diff --git a/.gitignore b/.gitignore
index 1052d7d8a..983986903 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,7 +4,9 @@
 /.tern-port
 /local
 /bin/_acorn.js
-/acorn/dist
+/acorn/dist/*
 /acorn-loose/dist
 /acorn-walk/dist
 /yarn.lock
+!/acorn/dist/acorn.d.ts
+!/acorn/dist/acorn.mjs.d.ts
\ No newline at end of file
diff --git a/AUTHORS b/AUTHORS
index c7a0fb8a0..f73abdf0d 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -30,11 +30,13 @@ Fabien LOISON
 Felix Maier
 Forbes Lindesay
 Gilad Peleg
+Huáng Jùnliàng
 impinball
 Ingvar Stepanyan
 Jackson Ray Hamilton
 Jesse McCarthy
 Jiaxing Wang
+Joe Krump
 Joel Kemp
 Johannes Herr
 John-David Dalton
@@ -68,6 +70,7 @@ Olivier Thomann
 Oskar Schöldström
 Paul Harper
 Peter Rust
+piotr
 PlNG
 Praveen N
 Prayag Verma
@@ -80,10 +83,15 @@ Sebastian McKenzie
 Shahar Soel
 Sheel Bedi
 Simen Bekkhus
+susiwen
+susiwen8
 Teddy Katz
 Timothy Gu
+Tim van der Lippe
 Toru Nagashima
+tuesmiddt
 Victor Homyakov
+Vladislav Tupikin
 Wexpo Lyu
 zsjforcn
 龙腾道
diff --git a/acorn-loose/CHANGELOG.md b/acorn-loose/CHANGELOG.md
index 83d191ec1..3c01af63b 100644
--- a/acorn-loose/CHANGELOG.md
+++ b/acorn-loose/CHANGELOG.md
@@ -1,3 +1,17 @@
+## 7.1.0 (2020-06-11)
+
+### Bug fixes
+
+Fix various issues in regexp validation.
+
+### New features
+
+Add support for `import.meta`.
+
+Add support for optional chaining (`?.`) and nullish coalescing (`??`).
+
+Support `export * as ns from "source"`.
+
 ## 7.0.0 (2019-08-12)
 
 ### Breaking changes
diff --git a/acorn-loose/LICENSE b/acorn-loose/LICENSE
index 2c0632b6a..cc5272c96 100644
--- a/acorn-loose/LICENSE
+++ b/acorn-loose/LICENSE
@@ -1,3 +1,5 @@
+MIT License
+
 Copyright (C) 2012-2018 by various contributors (see AUTHORS)
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
diff --git a/acorn-loose/README.md b/acorn-loose/README.md
index 3d8f5bac5..4641bd4fd 100644
--- a/acorn-loose/README.md
+++ b/acorn-loose/README.md
@@ -60,3 +60,7 @@ take the **`LooseParser`** class exported by the module, and call its
 static `extend` method with one or more plugins to get a customized
 parser class. The class has a static `parse` method that acts like the
 top-level `parse` method.
+
+**isDummy**`(node)` takes a `Node` and returns `true` if it is a dummy node
+inserted by the parser. The function performs a simple equality check on the
+node's name.
diff --git a/acorn-loose/package.json b/acorn-loose/package.json
index 4beee085e..3bb01da11 100644
--- a/acorn-loose/package.json
+++ b/acorn-loose/package.json
@@ -4,7 +4,7 @@
   "homepage": "https://github.com/acornjs/acorn",
   "main": "dist/acorn-loose.js",
   "module": "dist/acorn-loose.mjs",
-  "version": "7.0.0",
+  "version": "7.1.0",
   "engines": {"node": ">=0.4.0"},
   "dependencies": {
     "acorn": "^7.0.0"
diff --git a/acorn-loose/src/expression.js b/acorn-loose/src/expression.js
index dbc41bd60..4cfe1100d 100644
--- a/acorn-loose/src/expression.js
+++ b/acorn-loose/src/expression.js
@@ -102,7 +102,7 @@ lp.parseExprOp = function(left, start, minPrec, noIn, indent, line) {
         let rightStart = this.storeCurrentPos()
         node.right = this.parseExprOp(this.parseMaybeUnary(false), rightStart, prec, noIn, indent, line)
       }
-      this.finishNode(node, /&&|\|\|/.test(node.operator) ? "LogicalExpression" : "BinaryExpression")
+      this.finishNode(node, /&&|\|\||\?\?/.test(node.operator) ? "LogicalExpression" : "BinaryExpression")
       return this.parseExprOp(node, start, minPrec, noIn, indent, line)
     }
   }
@@ -159,17 +159,23 @@ lp.parseExprSubscripts = function() {
 }
 
 lp.parseSubscripts = function(base, start, noCalls, startIndent, line) {
+  const optionalSupported = this.options.ecmaVersion >= 11
+  let optionalChained = false
   for (;;) {
     if (this.curLineStart !== line && this.curIndent <= startIndent && this.tokenStartsLine()) {
       if (this.tok.type === tt.dot && this.curIndent === startIndent)
         --startIndent
       else
-        return base
+        break
     }
 
     let maybeAsyncArrow = base.type === "Identifier" && base.name === "async" && !this.canInsertSemicolon()
+    let optional = optionalSupported && this.eat(tt.questionDot)
+    if (optional) {
+      optionalChained = true
+    }
 
-    if (this.eat(tt.dot)) {
+    if ((optional && this.tok.type !== tt.parenL && this.tok.type !== tt.bracketL && this.tok.type !== tt.backQuote) || this.eat(tt.dot)) {
       let node = this.startNodeAt(start)
       node.object = base
       if (this.curLineStart !== line && this.curIndent <= startIndent && this.tokenStartsLine())
@@ -177,6 +183,9 @@ lp.parseSubscripts = function(base, start, noCalls, startIndent, line) {
       else
         node.property = this.parsePropertyAccessor() || this.dummyIdent()
       node.computed = false
+      if (optionalSupported) {
+        node.optional = optional
+      }
       base = this.finishNode(node, "MemberExpression")
     } else if (this.tok.type === tt.bracketL) {
       this.pushCx()
@@ -185,6 +194,9 @@ lp.parseSubscripts = function(base, start, noCalls, startIndent, line) {
       node.object = base
       node.property = this.parseExpression()
       node.computed = true
+      if (optionalSupported) {
+        node.optional = optional
+      }
       this.popCx()
       this.expect(tt.bracketR)
       base = this.finishNode(node, "MemberExpression")
@@ -195,6 +207,9 @@ lp.parseSubscripts = function(base, start, noCalls, startIndent, line) {
       let node = this.startNodeAt(start)
       node.callee = base
       node.arguments = exprList
+      if (optionalSupported) {
+        node.optional = optional
+      }
       base = this.finishNode(node, "CallExpression")
     } else if (this.tok.type === tt.backQuote) {
       let node = this.startNodeAt(start)
@@ -202,9 +217,16 @@ lp.parseSubscripts = function(base, start, noCalls, startIndent, line) {
       node.quasi = this.parseTemplate()
       base = this.finishNode(node, "TaggedTemplateExpression")
     } else {
-      return base
+      break
     }
   }
+
+  if (optionalChained) {
+    const chainNode = this.startNodeAt(start)
+    chainNode.expression = base
+    base = this.finishNode(chainNode, "ChainExpression")
+  }
+  return base
 }
 
 lp.parseExprAtom = function() {
@@ -244,7 +266,7 @@ lp.parseExprAtom = function() {
     node = this.startNode()
     node.value = this.tok.value
     node.raw = this.input.slice(this.tok.start, this.tok.end)
-    if (this.tok.type === tt.num && node.raw.charCodeAt(node.raw.length - 1) === 110) node.bigint = node.raw.slice(0, -1)
+    if (this.tok.type === tt.num && node.raw.charCodeAt(node.raw.length - 1) === 110) node.bigint = node.raw.slice(0, -1).replace(/_/g, "")
     this.next()
     return this.finishNode(node, "Literal")
 
@@ -310,10 +332,13 @@ lp.parseExprAtom = function() {
 
 lp.parseExprImport = function() {
   const node = this.startNode()
-  this.next() // skip `import`
+  const meta = this.parseIdent(true)
   switch (this.tok.type) {
   case tt.parenL:
     return this.parseDynamicImport(node)
+  case tt.dot:
+    node.meta = meta
+    return this.parseImportMeta(node)
   default:
     node.name = "import"
     return this.finishNode(node, "Identifier")
@@ -325,6 +350,12 @@ lp.parseDynamicImport = function(node) {
   return this.finishNode(node, "ImportExpression")
 }
 
+lp.parseImportMeta = function(node) {
+  this.next() // skip '.'
+  node.property = this.parseIdent(true)
+  return this.finishNode(node, "MetaProperty")
+}
+
 lp.parseNew = function() {
   let node = this.startNode(), startIndent = this.curIndent, line = this.curLineStart
   let meta = this.parseIdent(true)
diff --git a/acorn-loose/src/index.js b/acorn-loose/src/index.js
index 903781c5f..cfa0b497b 100644
--- a/acorn-loose/src/index.js
+++ b/acorn-loose/src/index.js
@@ -36,6 +36,7 @@ import "./statement"
 import "./expression"
 
 export {LooseParser} from "./state"
+export {isDummy} from "./parseutil"
 
 defaultOptions.tabSize = 4
 
diff --git a/acorn-loose/src/parseutil.js b/acorn-loose/src/parseutil.js
index 4501e2d46..534efd4b0 100644
--- a/acorn-loose/src/parseutil.js
+++ b/acorn-loose/src/parseutil.js
@@ -1 +1,3 @@
-export function isDummy(node) { return node.name === "✖" }
+export const dummyValue = "✖"
+
+export function isDummy(node) { return node.name === dummyValue }
diff --git a/acorn-loose/src/state.js b/acorn-loose/src/state.js
index 52887231d..322306fe4 100644
--- a/acorn-loose/src/state.js
+++ b/acorn-loose/src/state.js
@@ -1,4 +1,5 @@
 import {Parser, SourceLocation, tokTypes as tt, Node, lineBreak, isNewLine} from "acorn"
+import {dummyValue} from "./parseutil"
 
 function noop() {}
 
@@ -63,13 +64,13 @@ export class LooseParser {
 
   dummyIdent() {
     let dummy = this.dummyNode("Identifier")
-    dummy.name = "✖"
+    dummy.name = dummyValue
     return dummy
   }
 
   dummyString() {
     let dummy = this.dummyNode("Literal")
-    dummy.value = dummy.raw = "✖"
+    dummy.value = dummy.raw = dummyValue
     return dummy
   }
 
diff --git a/acorn-loose/src/statement.js b/acorn-loose/src/statement.js
index a5b574044..355d278f2 100644
--- a/acorn-loose/src/statement.js
+++ b/acorn-loose/src/statement.js
@@ -176,10 +176,13 @@ lp.parseStatement = function() {
     return this.parseClass(true)
 
   case tt._import:
-    if (this.options.ecmaVersion > 10 && this.lookAhead(1).type === tt.parenL) {
-      node.expression = this.parseExpression()
-      this.semicolon()
-      return this.finishNode(node, "ExpressionStatement")
+    if (this.options.ecmaVersion > 10) {
+      const nextType = this.lookAhead(1).type
+      if (nextType === tt.parenL || nextType === tt.dot) {
+        node.expression = this.parseExpression()
+        this.semicolon()
+        return this.finishNode(node, "ExpressionStatement")
+      }
     }
 
     return this.parseImport()
@@ -358,6 +361,13 @@ lp.parseExport = function() {
   let node = this.startNode()
   this.next()
   if (this.eat(tt.star)) {
+    if (this.options.ecmaVersion >= 11) {
+      if (this.eatContextual("as")) {
+        node.exported = this.parseExprAtom()
+      } else {
+        node.exported = null
+      }
+    }
     node.source = this.eatContextual("from") ? this.parseExprAtom() : this.dummyString()
     return this.finishNode(node, "ExportAllDeclaration")
   }
diff --git a/acorn-loose/src/tokenize.js b/acorn-loose/src/tokenize.js
index e838b48d8..da20b7daf 100644
--- a/acorn-loose/src/tokenize.js
+++ b/acorn-loose/src/tokenize.js
@@ -1,5 +1,6 @@
 import {tokTypes as tt, Token, isNewLine, SourceLocation, getLineInfo, lineBreakG} from "acorn"
 import {LooseParser} from "./state"
+import {dummyValue} from "./parseutil"
 
 const lp = LooseParser.prototype
 
@@ -73,7 +74,7 @@ lp.readToken = function() {
         throw e
       }
       this.resetTo(pos)
-      if (replace === true) replace = {start: pos, end: pos, type: tt.name, value: "✖"}
+      if (replace === true) replace = {start: pos, end: pos, type: tt.name, value: dummyValue}
       if (replace) {
         if (this.options.locations)
           replace.loc = new SourceLocation(
diff --git a/acorn-walk/CHANGELOG.md b/acorn-walk/CHANGELOG.md
index 82d439902..c6c2e058a 100644
--- a/acorn-walk/CHANGELOG.md
+++ b/acorn-walk/CHANGELOG.md
@@ -1,3 +1,25 @@
+## 7.2.0 (2020-06-17)
+
+### New features
+
+Support optional chaining and nullish coalescing.
+
+Support `import.meta`.
+
+Add support for `export * as ns from "source"`.
+
+## 7.1.1 (2020-02-13)
+
+### Bug fixes
+
+Clean up the type definitions to actually work well with the main parser.
+
+## 7.1.0 (2020-02-11)
+
+### New features
+
+Add a TypeScript definition file for the library.
+
 ## 7.0.0 (2017-08-12)
 
 ### New features
diff --git a/acorn-walk/LICENSE b/acorn-walk/LICENSE
index 2c0632b6a..cc5272c96 100644
--- a/acorn-walk/LICENSE
+++ b/acorn-walk/LICENSE
@@ -1,3 +1,5 @@
+MIT License
+
 Copyright (C) 2012-2018 by various contributors (see AUTHORS)
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
diff --git a/acorn-walk/dist/walk.d.ts b/acorn-walk/dist/walk.d.ts
new file mode 100644
index 000000000..00cc005f1
--- /dev/null
+++ b/acorn-walk/dist/walk.d.ts
@@ -0,0 +1,112 @@
+import {Node} from 'acorn';
+
+declare module "acorn-walk" {
+  type FullWalkerCallback<TState> = (
+    node: Node,
+    state: TState,
+    type: string
+  ) => void;
+
+  type FullAncestorWalkerCallback<TState> = (
+    node: Node,
+    state: TState | Node[],
+    ancestors: Node[],
+    type: string
+  ) => void;
+  type WalkerCallback<TState> = (node: Node, state: TState) => void;
+
+  type SimpleWalkerFn<TState> = (
+    node: Node,
+    state: TState
+  ) => void;
+  
+  type AncestorWalkerFn<TState> = (
+    node: Node,
+    state: TState| Node[],
+    ancestors: Node[]
+  ) => void;
+
+  type RecursiveWalkerFn<TState> = (
+    node: Node,
+    state: TState,
+    callback: WalkerCallback<TState>
+  ) => void;
+  
+  type SimpleVisitors<TState> = {
+    [type: string]: SimpleWalkerFn<TState>
+  };
+
+  type AncestorVisitors<TState> = {
+    [type: string]: AncestorWalkerFn<TState>
+  };
+  
+  type RecursiveVisitors<TState> = {
+    [type: string]: RecursiveWalkerFn<TState>
+  };
+
+  type FindPredicate = (type: string, node: Node) => boolean;
+
+  interface Found<TState> {
+    node: Node,
+    state: TState
+  }
+
+  export function simple<TState>(
+    node: Node,
+    visitors: SimpleVisitors<TState>,
+    base?: RecursiveVisitors<TState>,
+    state?: TState
+  ): void;
+
+  export function ancestor<TState>(
+    node: Node,
+    visitors: AncestorVisitors<TState>,
+    base?: RecursiveVisitors<TState>,
+    state?: TState
+  ): void;
+
+  export function recursive<TState>(
+    node: Node,
+    state: TState,
+    functions: RecursiveVisitors<TState>,
+    base?: RecursiveVisitors<TState>
+  ): void;
+
+  export function full<TState>(
+    node: Node,
+    callback: FullWalkerCallback<TState>,
+    base?: RecursiveVisitors<TState>,
+    state?: TState
+  ): void;
+
+  export function fullAncestor<TState>(
+    node: Node,
+    callback: FullAncestorWalkerCallback<TState>,
+    base?: RecursiveVisitors<TState>,
+    state?: TState
+  ): void;
+
+  export function make<TState>(
+    functions: RecursiveVisitors<TState>,
+    base?: RecursiveVisitors<TState>
+  ): RecursiveVisitors<TState>;
+
+  export function findNodeAt<TState>(
+    node: Node,
+    start: number | undefined,
+    end?: number | undefined,
+    type?: FindPredicate | string,
+    base?: RecursiveVisitors<TState>,
+    state?: TState
+  ): Found<TState> | undefined;
+
+  export function findNodeAround<TState>(
+    node: Node,
+    start: number | undefined,
+    type?: FindPredicate | string,
+    base?: RecursiveVisitors<TState>,
+    state?: TState
+  ): Found<TState> | undefined;
+
+  export const findNodeAfter: typeof findNodeAround;
+}
diff --git a/acorn-walk/package.json b/acorn-walk/package.json
index 375c21fc8..ae8da3cf3 100644
--- a/acorn-walk/package.json
+++ b/acorn-walk/package.json
@@ -3,8 +3,9 @@
   "description": "ECMAScript (ESTree) AST walker",
   "homepage": "https://github.com/acornjs/acorn",
   "main": "dist/walk.js",
+  "types": "dist/walk.d.ts",
   "module": "dist/walk.mjs",
-  "version": "7.0.0",
+  "version": "7.2.0",
   "engines": {"node": ">=0.4.0"},
   "maintainers": [
     {
diff --git a/acorn-walk/src/index.js b/acorn-walk/src/index.js
index d95af12be..2a044b7df 100644
--- a/acorn-walk/src/index.js
+++ b/acorn-walk/src/index.js
@@ -192,7 +192,7 @@ base.Program = base.BlockStatement = (node, st, c) => {
 }
 base.Statement = skipThrough
 base.EmptyStatement = ignore
-base.ExpressionStatement = base.ParenthesizedExpression =
+base.ExpressionStatement = base.ParenthesizedExpression = base.ChainExpression =
   (node, st, c) => c(node.expression, st, "Expression")
 base.IfStatement = (node, st, c) => {
   c(node.test, st, "Expression")
@@ -353,6 +353,8 @@ base.ExportNamedDeclaration = base.ExportDefaultDeclaration = (node, st, c) => {
   if (node.source) c(node.source, st, "Expression")
 }
 base.ExportAllDeclaration = (node, st, c) => {
+  if (node.exported)
+    c(node.exported, st)
   c(node.source, st, "Expression")
 }
 base.ImportDeclaration = (node, st, c) => {
diff --git a/acorn/CHANGELOG.md b/acorn/CHANGELOG.md
index e893c221a..164fd27c6 100644
--- a/acorn/CHANGELOG.md
+++ b/acorn/CHANGELOG.md
@@ -1,3 +1,61 @@
+## 7.4.0 (2020-08-03)
+
+### New features
+
+Add support for logical assignment operators.
+
+Add support for numeric separators.
+
+## 7.3.1 (2020-06-11)
+
+### Bug fixes
+
+Make the string in the `version` export match the actual library version.
+
+## 7.3.0 (2020-06-11)
+
+### Bug fixes
+
+Fix a bug that caused parsing of object patterns with a property named `set` that had a default value to fail.
+
+### New features
+
+Add support for optional chaining (`?.`).
+
+## 7.2.0 (2020-05-09)
+
+### Bug fixes
+
+Fix precedence issue in parsing of async arrow functions.
+
+### New features
+
+Add support for nullish coalescing.
+
+Add support for `import.meta`.
+
+Support `export * as ...` syntax.
+
+Upgrade to Unicode 13.
+
+## 6.4.1 (2020-03-09)
+
+### Bug fixes
+
+More carefully check for valid UTF16 surrogate pairs in regexp validator.
+
+## 7.1.1 (2020-03-01)
+
+### Bug fixes
+
+Treat `\8` and `\9` as invalid escapes in template strings.
+
+Allow unicode escapes in property names that are keywords.
+
+Don't error on an exponential operator expression as argument to `await`.
+
+More carefully check for valid UTF16 surrogate pairs in regexp validator.
+
 ## 7.1.0 (2019-09-24)
 
 ### Bug fixes
diff --git a/acorn/LICENSE b/acorn/LICENSE
index 2c0632b6a..cc5272c96 100644
--- a/acorn/LICENSE
+++ b/acorn/LICENSE
@@ -1,3 +1,5 @@
+MIT License
+
 Copyright (C) 2012-2018 by various contributors (see AUTHORS)
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
diff --git a/acorn/README.md b/acorn/README.md
index 585f2736f..52d2e9b71 100644
--- a/acorn/README.md
+++ b/acorn/README.md
@@ -266,5 +266,4 @@ Plugins for ECMAScript proposals:
  - [`acorn-stage3`](https://github.com/acornjs/acorn-stage3): Parse most stage 3 proposals, bundling:
    - [`acorn-class-fields`](https://github.com/acornjs/acorn-class-fields): Parse [class fields proposal](https://github.com/tc39/proposal-class-fields)
    - [`acorn-import-meta`](https://github.com/acornjs/acorn-import-meta): Parse [import.meta proposal](https://github.com/tc39/proposal-import-meta)
-   - [`acorn-numeric-separator`](https://github.com/acornjs/acorn-numeric-separator): Parse [numeric separator proposal](https://github.com/tc39/proposal-numeric-separator)
    - [`acorn-private-methods`](https://github.com/acornjs/acorn-private-methods): parse [private methods, getters and setters proposal](https://github.com/tc39/proposal-private-methods)n
diff --git a/acorn/dist/acorn.mjs.d.ts b/acorn/dist/acorn.mjs.d.ts
new file mode 100644
index 000000000..5f633595e
--- /dev/null
+++ b/acorn/dist/acorn.mjs.d.ts
@@ -0,0 +1,2 @@
+import * as acorn from "./acorn";
+export = acorn;
\ No newline at end of file
diff --git a/acorn/package.json b/acorn/package.json
index b9ff2b366..25bfa862b 100644
--- a/acorn/package.json
+++ b/acorn/package.json
@@ -3,8 +3,9 @@
   "description": "ECMAScript parser",
   "homepage": "https://github.com/acornjs/acorn",
   "main": "dist/acorn.js",
+  "types": "dist/acorn.d.ts",
   "module": "dist/acorn.mjs",
-  "version": "7.1.0",
+  "version": "7.4.0",
   "engines": {"node": ">=0.4.0"},
   "maintainers": [
     {
diff --git a/acorn/src/expression.js b/acorn/src/expression.js
index de4ebd0c9..d71701374 100644
--- a/acorn/src/expression.js
+++ b/acorn/src/expression.js
@@ -44,9 +44,11 @@ pp.checkPropClash = function(prop, propHash, refDestructuringErrors) {
   if (this.options.ecmaVersion >= 6) {
     if (name === "__proto__" && kind === "init") {
       if (propHash.proto) {
-        if (refDestructuringErrors && refDestructuringErrors.doubleProto < 0) refDestructuringErrors.doubleProto = key.start
-        // Backwards-compat kludge. Can be removed in version 6.0
-        else this.raiseRecoverable(key.start, "Redefinition of __proto__ property")
+        if (refDestructuringErrors) {
+          if (refDestructuringErrors.doubleProto < 0)
+            refDestructuringErrors.doubleProto = key.start
+          // Backwards-compat kludge. Can be removed in version 6.0
+        } else this.raiseRecoverable(key.start, "Redefinition of __proto__ property")
       }
       propHash.proto = true
     }
@@ -111,12 +113,11 @@ pp.parseMaybeAssign = function(noIn, refDestructuringErrors, afterLeftParse) {
     else this.exprAllowed = false
   }
 
-  let ownDestructuringErrors = false, oldParenAssign = -1, oldTrailingComma = -1, oldShorthandAssign = -1
+  let ownDestructuringErrors = false, oldParenAssign = -1, oldTrailingComma = -1
   if (refDestructuringErrors) {
     oldParenAssign = refDestructuringErrors.parenthesizedAssign
     oldTrailingComma = refDestructuringErrors.trailingComma
-    oldShorthandAssign = refDestructuringErrors.shorthandAssign
-    refDestructuringErrors.parenthesizedAssign = refDestructuringErrors.trailingComma = refDestructuringErrors.shorthandAssign = -1
+    refDestructuringErrors.parenthesizedAssign = refDestructuringErrors.trailingComma = -1
   } else {
     refDestructuringErrors = new DestructuringErrors
     ownDestructuringErrors = true
@@ -131,8 +132,11 @@ pp.parseMaybeAssign = function(noIn, refDestructuringErrors, afterLeftParse) {
     let node = this.startNodeAt(startPos, startLoc)
     node.operator = this.value
     node.left = this.type === tt.eq ? this.toAssignable(left, false, refDestructuringErrors) : left
-    if (!ownDestructuringErrors) DestructuringErrors.call(refDestructuringErrors)
-    refDestructuringErrors.shorthandAssign = -1 // reset because shorthand default was used correctly
+    if (!ownDestructuringErrors) {
+      refDestructuringErrors.parenthesizedAssign = refDestructuringErrors.trailingComma = refDestructuringErrors.doubleProto = -1
+    }
+    if (refDestructuringErrors.shorthandAssign >= node.left.start)
+      refDestructuringErrors.shorthandAssign = -1 // reset because shorthand default was used correctly
     this.checkLVal(left)
     this.next()
     node.right = this.parseMaybeAssign(noIn)
@@ -142,7 +146,6 @@ pp.parseMaybeAssign = function(noIn, refDestructuringErrors, afterLeftParse) {
   }
   if (oldParenAssign > -1) refDestructuringErrors.parenthesizedAssign = oldParenAssign
   if (oldTrailingComma > -1) refDestructuringErrors.trailingComma = oldTrailingComma
-  if (oldShorthandAssign > -1) refDestructuringErrors.shorthandAssign = oldShorthandAssign
   return left
 }
 
@@ -183,11 +186,20 @@ pp.parseExprOp = function(left, leftStartPos, leftStartLoc, minPrec, noIn) {
   if (prec != null && (!noIn || this.type !== tt._in)) {
     if (prec > minPrec) {
       let logical = this.type === tt.logicalOR || this.type === tt.logicalAND
+      let coalesce = this.type === tt.coalesce
+      if (coalesce) {
+        // Handle the precedence of `tt.coalesce` as equal to the range of logical expressions.
+        // In other words, `node.right` shouldn't contain logical expressions in order to check the mixed error.
+        prec = tt.logicalAND.binop
+      }
       let op = this.value
       this.next()
       let startPos = this.start, startLoc = this.startLoc
       let right = this.parseExprOp(this.parseMaybeUnary(null, false), startPos, startLoc, prec, noIn)
-      let node = this.buildBinary(leftStartPos, leftStartLoc, left, right, op, logical)
+      let node = this.buildBinary(leftStartPos, leftStartLoc, left, right, op, logical || coalesce)
+      if ((logical && this.type === tt.coalesce) || (coalesce && (this.type === tt.logicalOR || this.type === tt.logicalAND))) {
+        this.raiseRecoverable(this.start, "Logical expressions and coalesce expressions cannot be mixed. Wrap either by parentheses")
+      }
       return this.parseExprOp(node, leftStartPos, leftStartLoc, minPrec, noIn)
     }
   }
@@ -247,8 +259,8 @@ pp.parseMaybeUnary = function(refDestructuringErrors, sawUnary) {
 pp.parseExprSubscripts = function(refDestructuringErrors) {
   let startPos = this.start, startLoc = this.startLoc
   let expr = this.parseExprAtom(refDestructuringErrors)
-  let skipArrowSubscripts = expr.type === "ArrowFunctionExpression" && this.input.slice(this.lastTokStart, this.lastTokEnd) !== ")"
-  if (this.checkExpressionErrors(refDestructuringErrors) || skipArrowSubscripts) return expr
+  if (expr.type === "ArrowFunctionExpression" && this.input.slice(this.lastTokStart, this.lastTokEnd) !== ")")
+    return expr
   let result = this.parseSubscripts(expr, startPos, startLoc)
   if (refDestructuringErrors && result.type === "MemberExpression") {
     if (refDestructuringErrors.parenthesizedAssign >= result.start) refDestructuringErrors.parenthesizedAssign = -1
@@ -259,22 +271,42 @@ pp.parseExprSubscripts = function(refDestructuringErrors) {
 
 pp.parseSubscripts = function(base, startPos, startLoc, noCalls) {
   let maybeAsyncArrow = this.options.ecmaVersion >= 8 && base.type === "Identifier" && base.name === "async" &&
-      this.lastTokEnd === base.end && !this.canInsertSemicolon() && this.input.slice(base.start, base.end) === "async"
+      this.lastTokEnd === base.end && !this.canInsertSemicolon() && base.end - base.start === 5 &&
+      this.potentialArrowAt === base.start
+  let optionalChained = false
+
   while (true) {
-    let element = this.parseSubscript(base, startPos, startLoc, noCalls, maybeAsyncArrow)
-    if (element === base || element.type === "ArrowFunctionExpression") return element
+    let element = this.parseSubscript(base, startPos, startLoc, noCalls, maybeAsyncArrow, optionalChained)
+
+    if (element.optional) optionalChained = true
+    if (element === base || element.type === "ArrowFunctionExpression") {
+      if (optionalChained) {
+        const chainNode = this.startNodeAt(startPos, startLoc)
+        chainNode.expression = element
+        element = this.finishNode(chainNode, "ChainExpression")
+      }
+      return element
+    }
+
     base = element
   }
 }
 
-pp.parseSubscript = function(base, startPos, startLoc, noCalls, maybeAsyncArrow) {
+pp.parseSubscript = function(base, startPos, startLoc, noCalls, maybeAsyncArrow, optionalChained) {
+  let optionalSupported = this.options.ecmaVersion >= 11
+  let optional = optionalSupported && this.eat(tt.questionDot)
+  if (noCalls && optional) this.raise(this.lastTokStart, "Optional chaining cannot appear in the callee of new expressions")
+
   let computed = this.eat(tt.bracketL)
-  if (computed || this.eat(tt.dot)) {
+  if (computed || (optional && this.type !== tt.parenL && this.type !== tt.backQuote) || this.eat(tt.dot)) {
     let node = this.startNodeAt(startPos, startLoc)
     node.object = base
     node.property = computed ? this.parseExpression() : this.parseIdent(this.options.allowReserved !== "never")
     node.computed = !!computed
     if (computed) this.expect(tt.bracketR)
+    if (optionalSupported) {
+      node.optional = optional
+    }
     base = this.finishNode(node, "MemberExpression")
   } else if (!noCalls && this.eat(tt.parenL)) {
     let refDestructuringErrors = new DestructuringErrors, oldYieldPos = this.yieldPos, oldAwaitPos = this.awaitPos, oldAwaitIdentPos = this.awaitIdentPos
@@ -282,7 +314,7 @@ pp.parseSubscript = function(base, startPos, startLoc, noCalls, maybeAsyncArrow)
     this.awaitPos = 0
     this.awaitIdentPos = 0
     let exprList = this.parseExprList(tt.parenR, this.options.ecmaVersion >= 8, false, refDestructuringErrors)
-    if (maybeAsyncArrow && !this.canInsertSemicolon() && this.eat(tt.arrow)) {
+    if (maybeAsyncArrow && !optional && !this.canInsertSemicolon() && this.eat(tt.arrow)) {
       this.checkPatternErrors(refDestructuringErrors, false)
       this.checkYieldAwaitInDefaultParams()
       if (this.awaitIdentPos > 0)
@@ -299,8 +331,14 @@ pp.parseSubscript = function(base, startPos, startLoc, noCalls, maybeAsyncArrow)
     let node = this.startNodeAt(startPos, startLoc)
     node.callee = base
     node.arguments = exprList
+    if (optionalSupported) {
+      node.optional = optional
+    }
     base = this.finishNode(node, "CallExpression")
   } else if (this.type === tt.backQuote) {
+    if (optional || optionalChained) {
+      this.raise(this.start, "Optional chaining cannot appear in the tag of tagged template expressions")
+    }
     let node = this.startNodeAt(startPos, startLoc)
     node.tag = base
     node.quasi = this.parseTemplate({isTagged: true})
@@ -423,10 +461,18 @@ pp.parseExprAtom = function(refDestructuringErrors) {
 
 pp.parseExprImport = function() {
   const node = this.startNode()
-  this.next() // skip `import`
+
+  // Consume `import` as an identifier for `import.meta`.
+  // Because `this.parseIdent(true)` doesn't check escape sequences, it needs the check of `this.containsEsc`.
+  if (this.containsEsc) this.raiseRecoverable(this.start, "Escape sequence in keyword import")
+  const meta = this.parseIdent(true)
+
   switch (this.type) {
   case tt.parenL:
     return this.parseDynamicImport(node)
+  case tt.dot:
+    node.meta = meta
+    return this.parseImportMeta(node)
   default:
     this.unexpected()
   }
@@ -451,11 +497,27 @@ pp.parseDynamicImport = function(node) {
   return this.finishNode(node, "ImportExpression")
 }
 
+pp.parseImportMeta = function(node) {
+  this.next() // skip `.`
+
+  const containsEsc = this.containsEsc
+  node.property = this.parseIdent(true)
+
+  if (node.property.name !== "meta")
+    this.raiseRecoverable(node.property.start, "The only valid meta property for import is 'import.meta'")
+  if (containsEsc)
+    this.raiseRecoverable(node.start, "'import.meta' must not contain escaped characters")
+  if (this.options.sourceType !== "module")
+    this.raiseRecoverable(node.start, "Cannot use 'import.meta' outside a module")
+
+  return this.finishNode(node, "MetaProperty")
+}
+
 pp.parseLiteral = function(value) {
   let node = this.startNode()
   node.value = value
   node.raw = this.input.slice(this.start, this.end)
-  if (node.raw.charCodeAt(node.raw.length - 1) === 110) node.bigint = node.raw.slice(0, -1)
+  if (node.raw.charCodeAt(node.raw.length - 1) === 110) node.bigint = node.raw.slice(0, -1).replace(/_/g, "")
   this.next()
   return this.finishNode(node, "Literal")
 }
@@ -546,16 +608,19 @@ pp.parseParenArrowList = function(startPos, startLoc, exprList) {
 const empty = []
 
 pp.parseNew = function() {
+  if (this.containsEsc) this.raiseRecoverable(this.start, "Escape sequence in keyword new")
   let node = this.startNode()
   let meta = this.parseIdent(true)
   if (this.options.ecmaVersion >= 6 && this.eat(tt.dot)) {
     node.meta = meta
     let containsEsc = this.containsEsc
     node.property = this.parseIdent(true)
-    if (node.property.name !== "target" || containsEsc)
-      this.raiseRecoverable(node.property.start, "The only valid meta property for new is new.target")
+    if (node.property.name !== "target")
+      this.raiseRecoverable(node.property.start, "The only valid meta property for new is 'new.target'")
+    if (containsEsc)
+      this.raiseRecoverable(node.start, "'new.target' must not contain escaped characters")
     if (!this.inNonArrowFunction())
-      this.raiseRecoverable(node.start, "new.target can only be used in functions")
+      this.raiseRecoverable(node.start, "'new.target' can only be used in functions")
     return this.finishNode(node, "MetaProperty")
   }
   let startPos = this.start, startLoc = this.startLoc, isImport = this.type === tt._import
@@ -699,7 +764,7 @@ pp.parsePropertyValue = function(prop, isPattern, isGenerator, isAsync, startPos
   } else if (!isPattern && !containsEsc &&
              this.options.ecmaVersion >= 5 && !prop.computed && prop.key.type === "Identifier" &&
              (prop.key.name === "get" || prop.key.name === "set") &&
-             (this.type !== tt.comma && this.type !== tt.braceR)) {
+             (this.type !== tt.comma && this.type !== tt.braceR && this.type !== tt.eq)) {
     if (isGenerator || isAsync) this.unexpected()
     prop.kind = prop.key.name
     this.parsePropertyName(prop)
@@ -834,16 +899,14 @@ pp.parseFunctionBody = function(node, isArrowFunction, isMethod) {
     // Add the params to varDeclaredNames to ensure that an error is thrown
     // if a let/const declaration in the function clashes with one of the params.
     this.checkParams(node, !oldStrict && !useStrict && !isArrowFunction && !isMethod && this.isSimpleParamList(node.params))
-    node.body = this.parseBlock(false)
+    // Ensure the function name isn't a forbidden identifier in strict mode, e.g. 'eval'
+    if (this.strict && node.id) this.checkLVal(node.id, BIND_OUTSIDE)
+    node.body = this.parseBlock(false, undefined, useStrict && !oldStrict)
     node.expression = false
     this.adaptDirectivePrologue(node.body.body)
     this.labels = oldLabels
   }
   this.exitScope()
-
-  // Ensure the function name isn't a forbidden identifier in strict mode, e.g. 'eval'
-  if (this.strict && node.id) this.checkLVal(node.id, BIND_OUTSIDE)
-  this.strict = oldStrict
 }
 
 pp.isSimpleParamList = function(params) {
@@ -929,7 +992,7 @@ pp.parseIdent = function(liberal, isBinding) {
   } else {
     this.unexpected()
   }
-  this.next()
+  this.next(!!liberal)
   this.finishNode(node, "Identifier")
   if (!liberal) {
     this.checkUnreserved(node)
@@ -961,6 +1024,6 @@ pp.parseAwait = function() {
 
   let node = this.startNode()
   this.next()
-  node.argument = this.parseMaybeUnary(null, true)
+  node.argument = this.parseMaybeUnary(null, false)
   return this.finishNode(node, "AwaitExpression")
 }
diff --git a/acorn/src/identifier.js b/acorn/src/identifier.js
index 339066260..0d7c3d136 100644
--- a/acorn/src/identifier.js
+++ b/acorn/src/identifier.js
@@ -27,8 +27,8 @@ export const keywordRelationalOperator = /^in(stanceof)?$/
 // are only applied when a character is found to actually have a
 // code point above 128.
 // Generated by `bin/generate-identifier-regex.js`.
-let nonASCIIidentifierStartChars = "\xaa\xb5\xba\xc0-\xd6\xd8-\xf6\xf8-\u02c1\u02c6-\u02d1\u02e0-\u02e4\u02ec\u02ee\u0370-\u0374\u0376\u0377\u037a-\u037d\u037f\u0386\u0388-\u038a\u038c\u038e-\u03a1\u03a3-\u03f5\u03f7-\u0481\u048a-\u052f\u0531-\u0556\u0559\u0560-\u0588\u05d0-\u05ea\u05ef-\u05f2\u0620-\u064a\u066e\u066f\u0671-\u06d3\u06d5\u06e5\u06e6\u06ee\u06ef\u06fa-\u06fc\u06ff\u0710\u0712-\u072f\u074d-\u07a5\u07b1\u07ca-\u07ea\u07f4\u07f5\u07fa\u0800-\u0815\u081a\u0824\u0828\u0840-\u0858\u0860-\u086a\u08a0-\u08b4\u08b6-\u08bd\u0904-\u0939\u093d\u0950\u0958-\u0961\u0971-\u0980\u0985-\u098c\u098f\u0990\u0993-\u09a8\u09aa-\u09b0\u09b2\u09b6-\u09b9\u09bd\u09ce\u09dc\u09dd\u09df-\u09e1\u09f0\u09f1\u09fc\u0a05-\u0a0a\u0a0f\u0a10\u0a13-\u0a28\u0a2a-\u0a30\u0a32\u0a33\u0a35\u0a36\u0a38\u0a39\u0a59-\u0a5c\u0a5e\u0a72-\u0a74\u0a85-\u0a8d\u0a8f-\u0a91\u0a93-\u0aa8\u0aaa-\u0ab0\u0ab2\u0ab3\u0ab5-\u0ab9\u0abd\u0ad0\u0ae0\u0ae1\u0af9\u0b05-\u0b0c\u0b0f\u0b10\u0b13-\u0b28\u0b2a-\u0b30\u0b32\u0b33\u0b35-\u0b39\u0b3d\u0b5c\u0b5d\u0b5f-\u0b61\u0b71\u0b83\u0b85-\u0b8a\u0b8e-\u0b90\u0b92-\u0b95\u0b99\u0b9a\u0b9c\u0b9e\u0b9f\u0ba3\u0ba4\u0ba8-\u0baa\u0bae-\u0bb9\u0bd0\u0c05-\u0c0c\u0c0e-\u0c10\u0c12-\u0c28\u0c2a-\u0c39\u0c3d\u0c58-\u0c5a\u0c60\u0c61\u0c80\u0c85-\u0c8c\u0c8e-\u0c90\u0c92-\u0ca8\u0caa-\u0cb3\u0cb5-\u0cb9\u0cbd\u0cde\u0ce0\u0ce1\u0cf1\u0cf2\u0d05-\u0d0c\u0d0e-\u0d10\u0d12-\u0d3a\u0d3d\u0d4e\u0d54-\u0d56\u0d5f-\u0d61\u0d7a-\u0d7f\u0d85-\u0d96\u0d9a-\u0db1\u0db3-\u0dbb\u0dbd\u0dc0-\u0dc6\u0e01-\u0e30\u0e32\u0e33\u0e40-\u0e46\u0e81\u0e82\u0e84\u0e86-\u0e8a\u0e8c-\u0ea3\u0ea5\u0ea7-\u0eb0\u0eb2\u0eb3\u0ebd\u0ec0-\u0ec4\u0ec6\u0edc-\u0edf\u0f00\u0f40-\u0f47\u0f49-\u0f6c\u0f88-\u0f8c\u1000-\u102a\u103f\u1050-\u1055\u105a-\u105d\u1061\u1065\u1066\u106e-\u1070\u1075-\u1081\u108e\u10a0-\u10c5\u10c7\u10cd\u10d0-\u10fa\u10fc-\u1248\u124a-\u124d\u1250-\u1256\u1258\u125a-\u125d\u1260-\u1288\u128a-\u128d\u1290-\u12b0\u12b2-\u12b5\u12b8-\u12be\u12c0\u12c2-\u12c5\u12c8-\u12d6\u12d8-\u1310\u1312-\u1315\u1318-\u135a\u1380-\u138f\u13a0-\u13f5\u13f8-\u13fd\u1401-\u166c\u166f-\u167f\u1681-\u169a\u16a0-\u16ea\u16ee-\u16f8\u1700-\u170c\u170e-\u1711\u1720-\u1731\u1740-\u1751\u1760-\u176c\u176e-\u1770\u1780-\u17b3\u17d7\u17dc\u1820-\u1878\u1880-\u18a8\u18aa\u18b0-\u18f5\u1900-\u191e\u1950-\u196d\u1970-\u1974\u1980-\u19ab\u19b0-\u19c9\u1a00-\u1a16\u1a20-\u1a54\u1aa7\u1b05-\u1b33\u1b45-\u1b4b\u1b83-\u1ba0\u1bae\u1baf\u1bba-\u1be5\u1c00-\u1c23\u1c4d-\u1c4f\u1c5a-\u1c7d\u1c80-\u1c88\u1c90-\u1cba\u1cbd-\u1cbf\u1ce9-\u1cec\u1cee-\u1cf3\u1cf5\u1cf6\u1cfa\u1d00-\u1dbf\u1e00-\u1f15\u1f18-\u1f1d\u1f20-\u1f45\u1f48-\u1f4d\u1f50-\u1f57\u1f59\u1f5b\u1f5d\u1f5f-\u1f7d\u1f80-\u1fb4\u1fb6-\u1fbc\u1fbe\u1fc2-\u1fc4\u1fc6-\u1fcc\u1fd0-\u1fd3\u1fd6-\u1fdb\u1fe0-\u1fec\u1ff2-\u1ff4\u1ff6-\u1ffc\u2071\u207f\u2090-\u209c\u2102\u2107\u210a-\u2113\u2115\u2118-\u211d\u2124\u2126\u2128\u212a-\u2139\u213c-\u213f\u2145-\u2149\u214e\u2160-\u2188\u2c00-\u2c2e\u2c30-\u2c5e\u2c60-\u2ce4\u2ceb-\u2cee\u2cf2\u2cf3\u2d00-\u2d25\u2d27\u2d2d\u2d30-\u2d67\u2d6f\u2d80-\u2d96\u2da0-\u2da6\u2da8-\u2dae\u2db0-\u2db6\u2db8-\u2dbe\u2dc0-\u2dc6\u2dc8-\u2dce\u2dd0-\u2dd6\u2dd8-\u2dde\u3005-\u3007\u3021-\u3029\u3031-\u3035\u3038-\u303c\u3041-\u3096\u309b-\u309f\u30a1-\u30fa\u30fc-\u30ff\u3105-\u312f\u3131-\u318e\u31a0-\u31ba\u31f0-\u31ff\u3400-\u4db5\u4e00-\u9fef\ua000-\ua48c\ua4d0-\ua4fd\ua500-\ua60c\ua610-\ua61f\ua62a\ua62b\ua640-\ua66e\ua67f-\ua69d\ua6a0-\ua6ef\ua717-\ua71f\ua722-\ua788\ua78b-\ua7bf\ua7c2-\ua7c6\ua7f7-\ua801\ua803-\ua805\ua807-\ua80a\ua80c-\ua822\ua840-\ua873\ua882-\ua8b3\ua8f2-\ua8f7\ua8fb\ua8fd\ua8fe\ua90a-\ua925\ua930-\ua946\ua960-\ua97c\ua984-\ua9b2\ua9cf\ua9e0-\ua9e4\ua9e6-\ua9ef\ua9fa-\ua9fe\uaa00-\uaa28\uaa40-\uaa42\uaa44-\uaa4b\uaa60-\uaa76\uaa7a\uaa7e-\uaaaf\uaab1\uaab5\uaab6\uaab9-\uaabd\uaac0\uaac2\uaadb-\uaadd\uaae0-\uaaea\uaaf2-\uaaf4\uab01-\uab06\uab09-\uab0e\uab11-\uab16\uab20-\uab26\uab28-\uab2e\uab30-\uab5a\uab5c-\uab67\uab70-\uabe2\uac00-\ud7a3\ud7b0-\ud7c6\ud7cb-\ud7fb\uf900-\ufa6d\ufa70-\ufad9\ufb00-\ufb06\ufb13-\ufb17\ufb1d\ufb1f-\ufb28\ufb2a-\ufb36\ufb38-\ufb3c\ufb3e\ufb40\ufb41\ufb43\ufb44\ufb46-\ufbb1\ufbd3-\ufd3d\ufd50-\ufd8f\ufd92-\ufdc7\ufdf0-\ufdfb\ufe70-\ufe74\ufe76-\ufefc\uff21-\uff3a\uff41-\uff5a\uff66-\uffbe\uffc2-\uffc7\uffca-\uffcf\uffd2-\uffd7\uffda-\uffdc"
-let nonASCIIidentifierChars = "\u200c\u200d\xb7\u0300-\u036f\u0387\u0483-\u0487\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u064b-\u0669\u0670\u06d6-\u06dc\u06df-\u06e4\u06e7\u06e8\u06ea-\u06ed\u06f0-\u06f9\u0711\u0730-\u074a\u07a6-\u07b0\u07c0-\u07c9\u07eb-\u07f3\u07fd\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0859-\u085b\u08d3-\u08e1\u08e3-\u0903\u093a-\u093c\u093e-\u094f\u0951-\u0957\u0962\u0963\u0966-\u096f\u0981-\u0983\u09bc\u09be-\u09c4\u09c7\u09c8\u09cb-\u09cd\u09d7\u09e2\u09e3\u09e6-\u09ef\u09fe\u0a01-\u0a03\u0a3c\u0a3e-\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a66-\u0a71\u0a75\u0a81-\u0a83\u0abc\u0abe-\u0ac5\u0ac7-\u0ac9\u0acb-\u0acd\u0ae2\u0ae3\u0ae6-\u0aef\u0afa-\u0aff\u0b01-\u0b03\u0b3c\u0b3e-\u0b44\u0b47\u0b48\u0b4b-\u0b4d\u0b56\u0b57\u0b62\u0b63\u0b66-\u0b6f\u0b82\u0bbe-\u0bc2\u0bc6-\u0bc8\u0bca-\u0bcd\u0bd7\u0be6-\u0bef\u0c00-\u0c04\u0c3e-\u0c44\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62\u0c63\u0c66-\u0c6f\u0c81-\u0c83\u0cbc\u0cbe-\u0cc4\u0cc6-\u0cc8\u0cca-\u0ccd\u0cd5\u0cd6\u0ce2\u0ce3\u0ce6-\u0cef\u0d00-\u0d03\u0d3b\u0d3c\u0d3e-\u0d44\u0d46-\u0d48\u0d4a-\u0d4d\u0d57\u0d62\u0d63\u0d66-\u0d6f\u0d82\u0d83\u0dca\u0dcf-\u0dd4\u0dd6\u0dd8-\u0ddf\u0de6-\u0def\u0df2\u0df3\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0e50-\u0e59\u0eb1\u0eb4-\u0ebc\u0ec8-\u0ecd\u0ed0-\u0ed9\u0f18\u0f19\u0f20-\u0f29\u0f35\u0f37\u0f39\u0f3e\u0f3f\u0f71-\u0f84\u0f86\u0f87\u0f8d-\u0f97\u0f99-\u0fbc\u0fc6\u102b-\u103e\u1040-\u1049\u1056-\u1059\u105e-\u1060\u1062-\u1064\u1067-\u106d\u1071-\u1074\u1082-\u108d\u108f-\u109d\u135d-\u135f\u1369-\u1371\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17b4-\u17d3\u17dd\u17e0-\u17e9\u180b-\u180d\u1810-\u1819\u18a9\u1920-\u192b\u1930-\u193b\u1946-\u194f\u19d0-\u19da\u1a17-\u1a1b\u1a55-\u1a5e\u1a60-\u1a7c\u1a7f-\u1a89\u1a90-\u1a99\u1ab0-\u1abd\u1b00-\u1b04\u1b34-\u1b44\u1b50-\u1b59\u1b6b-\u1b73\u1b80-\u1b82\u1ba1-\u1bad\u1bb0-\u1bb9\u1be6-\u1bf3\u1c24-\u1c37\u1c40-\u1c49\u1c50-\u1c59\u1cd0-\u1cd2\u1cd4-\u1ce8\u1ced\u1cf4\u1cf7-\u1cf9\u1dc0-\u1df9\u1dfb-\u1dff\u203f\u2040\u2054\u20d0-\u20dc\u20e1\u20e5-\u20f0\u2cef-\u2cf1\u2d7f\u2de0-\u2dff\u302a-\u302f\u3099\u309a\ua620-\ua629\ua66f\ua674-\ua67d\ua69e\ua69f\ua6f0\ua6f1\ua802\ua806\ua80b\ua823-\ua827\ua880\ua881\ua8b4-\ua8c5\ua8d0-\ua8d9\ua8e0-\ua8f1\ua8ff-\ua909\ua926-\ua92d\ua947-\ua953\ua980-\ua983\ua9b3-\ua9c0\ua9d0-\ua9d9\ua9e5\ua9f0-\ua9f9\uaa29-\uaa36\uaa43\uaa4c\uaa4d\uaa50-\uaa59\uaa7b-\uaa7d\uaab0\uaab2-\uaab4\uaab7\uaab8\uaabe\uaabf\uaac1\uaaeb-\uaaef\uaaf5\uaaf6\uabe3-\uabea\uabec\uabed\uabf0-\uabf9\ufb1e\ufe00-\ufe0f\ufe20-\ufe2f\ufe33\ufe34\ufe4d-\ufe4f\uff10-\uff19\uff3f"
+let nonASCIIidentifierStartChars = "\xaa\xb5\xba\xc0-\xd6\xd8-\xf6\xf8-\u02c1\u02c6-\u02d1\u02e0-\u02e4\u02ec\u02ee\u0370-\u0374\u0376\u0377\u037a-\u037d\u037f\u0386\u0388-\u038a\u038c\u038e-\u03a1\u03a3-\u03f5\u03f7-\u0481\u048a-\u052f\u0531-\u0556\u0559\u0560-\u0588\u05d0-\u05ea\u05ef-\u05f2\u0620-\u064a\u066e\u066f\u0671-\u06d3\u06d5\u06e5\u06e6\u06ee\u06ef\u06fa-\u06fc\u06ff\u0710\u0712-\u072f\u074d-\u07a5\u07b1\u07ca-\u07ea\u07f4\u07f5\u07fa\u0800-\u0815\u081a\u0824\u0828\u0840-\u0858\u0860-\u086a\u08a0-\u08b4\u08b6-\u08c7\u0904-\u0939\u093d\u0950\u0958-\u0961\u0971-\u0980\u0985-\u098c\u098f\u0990\u0993-\u09a8\u09aa-\u09b0\u09b2\u09b6-\u09b9\u09bd\u09ce\u09dc\u09dd\u09df-\u09e1\u09f0\u09f1\u09fc\u0a05-\u0a0a\u0a0f\u0a10\u0a13-\u0a28\u0a2a-\u0a30\u0a32\u0a33\u0a35\u0a36\u0a38\u0a39\u0a59-\u0a5c\u0a5e\u0a72-\u0a74\u0a85-\u0a8d\u0a8f-\u0a91\u0a93-\u0aa8\u0aaa-\u0ab0\u0ab2\u0ab3\u0ab5-\u0ab9\u0abd\u0ad0\u0ae0\u0ae1\u0af9\u0b05-\u0b0c\u0b0f\u0b10\u0b13-\u0b28\u0b2a-\u0b30\u0b32\u0b33\u0b35-\u0b39\u0b3d\u0b5c\u0b5d\u0b5f-\u0b61\u0b71\u0b83\u0b85-\u0b8a\u0b8e-\u0b90\u0b92-\u0b95\u0b99\u0b9a\u0b9c\u0b9e\u0b9f\u0ba3\u0ba4\u0ba8-\u0baa\u0bae-\u0bb9\u0bd0\u0c05-\u0c0c\u0c0e-\u0c10\u0c12-\u0c28\u0c2a-\u0c39\u0c3d\u0c58-\u0c5a\u0c60\u0c61\u0c80\u0c85-\u0c8c\u0c8e-\u0c90\u0c92-\u0ca8\u0caa-\u0cb3\u0cb5-\u0cb9\u0cbd\u0cde\u0ce0\u0ce1\u0cf1\u0cf2\u0d04-\u0d0c\u0d0e-\u0d10\u0d12-\u0d3a\u0d3d\u0d4e\u0d54-\u0d56\u0d5f-\u0d61\u0d7a-\u0d7f\u0d85-\u0d96\u0d9a-\u0db1\u0db3-\u0dbb\u0dbd\u0dc0-\u0dc6\u0e01-\u0e30\u0e32\u0e33\u0e40-\u0e46\u0e81\u0e82\u0e84\u0e86-\u0e8a\u0e8c-\u0ea3\u0ea5\u0ea7-\u0eb0\u0eb2\u0eb3\u0ebd\u0ec0-\u0ec4\u0ec6\u0edc-\u0edf\u0f00\u0f40-\u0f47\u0f49-\u0f6c\u0f88-\u0f8c\u1000-\u102a\u103f\u1050-\u1055\u105a-\u105d\u1061\u1065\u1066\u106e-\u1070\u1075-\u1081\u108e\u10a0-\u10c5\u10c7\u10cd\u10d0-\u10fa\u10fc-\u1248\u124a-\u124d\u1250-\u1256\u1258\u125a-\u125d\u1260-\u1288\u128a-\u128d\u1290-\u12b0\u12b2-\u12b5\u12b8-\u12be\u12c0\u12c2-\u12c5\u12c8-\u12d6\u12d8-\u1310\u1312-\u1315\u1318-\u135a\u1380-\u138f\u13a0-\u13f5\u13f8-\u13fd\u1401-\u166c\u166f-\u167f\u1681-\u169a\u16a0-\u16ea\u16ee-\u16f8\u1700-\u170c\u170e-\u1711\u1720-\u1731\u1740-\u1751\u1760-\u176c\u176e-\u1770\u1780-\u17b3\u17d7\u17dc\u1820-\u1878\u1880-\u18a8\u18aa\u18b0-\u18f5\u1900-\u191e\u1950-\u196d\u1970-\u1974\u1980-\u19ab\u19b0-\u19c9\u1a00-\u1a16\u1a20-\u1a54\u1aa7\u1b05-\u1b33\u1b45-\u1b4b\u1b83-\u1ba0\u1bae\u1baf\u1bba-\u1be5\u1c00-\u1c23\u1c4d-\u1c4f\u1c5a-\u1c7d\u1c80-\u1c88\u1c90-\u1cba\u1cbd-\u1cbf\u1ce9-\u1cec\u1cee-\u1cf3\u1cf5\u1cf6\u1cfa\u1d00-\u1dbf\u1e00-\u1f15\u1f18-\u1f1d\u1f20-\u1f45\u1f48-\u1f4d\u1f50-\u1f57\u1f59\u1f5b\u1f5d\u1f5f-\u1f7d\u1f80-\u1fb4\u1fb6-\u1fbc\u1fbe\u1fc2-\u1fc4\u1fc6-\u1fcc\u1fd0-\u1fd3\u1fd6-\u1fdb\u1fe0-\u1fec\u1ff2-\u1ff4\u1ff6-\u1ffc\u2071\u207f\u2090-\u209c\u2102\u2107\u210a-\u2113\u2115\u2118-\u211d\u2124\u2126\u2128\u212a-\u2139\u213c-\u213f\u2145-\u2149\u214e\u2160-\u2188\u2c00-\u2c2e\u2c30-\u2c5e\u2c60-\u2ce4\u2ceb-\u2cee\u2cf2\u2cf3\u2d00-\u2d25\u2d27\u2d2d\u2d30-\u2d67\u2d6f\u2d80-\u2d96\u2da0-\u2da6\u2da8-\u2dae\u2db0-\u2db6\u2db8-\u2dbe\u2dc0-\u2dc6\u2dc8-\u2dce\u2dd0-\u2dd6\u2dd8-\u2dde\u3005-\u3007\u3021-\u3029\u3031-\u3035\u3038-\u303c\u3041-\u3096\u309b-\u309f\u30a1-\u30fa\u30fc-\u30ff\u3105-\u312f\u3131-\u318e\u31a0-\u31bf\u31f0-\u31ff\u3400-\u4dbf\u4e00-\u9ffc\ua000-\ua48c\ua4d0-\ua4fd\ua500-\ua60c\ua610-\ua61f\ua62a\ua62b\ua640-\ua66e\ua67f-\ua69d\ua6a0-\ua6ef\ua717-\ua71f\ua722-\ua788\ua78b-\ua7bf\ua7c2-\ua7ca\ua7f5-\ua801\ua803-\ua805\ua807-\ua80a\ua80c-\ua822\ua840-\ua873\ua882-\ua8b3\ua8f2-\ua8f7\ua8fb\ua8fd\ua8fe\ua90a-\ua925\ua930-\ua946\ua960-\ua97c\ua984-\ua9b2\ua9cf\ua9e0-\ua9e4\ua9e6-\ua9ef\ua9fa-\ua9fe\uaa00-\uaa28\uaa40-\uaa42\uaa44-\uaa4b\uaa60-\uaa76\uaa7a\uaa7e-\uaaaf\uaab1\uaab5\uaab6\uaab9-\uaabd\uaac0\uaac2\uaadb-\uaadd\uaae0-\uaaea\uaaf2-\uaaf4\uab01-\uab06\uab09-\uab0e\uab11-\uab16\uab20-\uab26\uab28-\uab2e\uab30-\uab5a\uab5c-\uab69\uab70-\uabe2\uac00-\ud7a3\ud7b0-\ud7c6\ud7cb-\ud7fb\uf900-\ufa6d\ufa70-\ufad9\ufb00-\ufb06\ufb13-\ufb17\ufb1d\ufb1f-\ufb28\ufb2a-\ufb36\ufb38-\ufb3c\ufb3e\ufb40\ufb41\ufb43\ufb44\ufb46-\ufbb1\ufbd3-\ufd3d\ufd50-\ufd8f\ufd92-\ufdc7\ufdf0-\ufdfb\ufe70-\ufe74\ufe76-\ufefc\uff21-\uff3a\uff41-\uff5a\uff66-\uffbe\uffc2-\uffc7\uffca-\uffcf\uffd2-\uffd7\uffda-\uffdc"
+let nonASCIIidentifierChars = "\u200c\u200d\xb7\u0300-\u036f\u0387\u0483-\u0487\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u064b-\u0669\u0670\u06d6-\u06dc\u06df-\u06e4\u06e7\u06e8\u06ea-\u06ed\u06f0-\u06f9\u0711\u0730-\u074a\u07a6-\u07b0\u07c0-\u07c9\u07eb-\u07f3\u07fd\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0859-\u085b\u08d3-\u08e1\u08e3-\u0903\u093a-\u093c\u093e-\u094f\u0951-\u0957\u0962\u0963\u0966-\u096f\u0981-\u0983\u09bc\u09be-\u09c4\u09c7\u09c8\u09cb-\u09cd\u09d7\u09e2\u09e3\u09e6-\u09ef\u09fe\u0a01-\u0a03\u0a3c\u0a3e-\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a66-\u0a71\u0a75\u0a81-\u0a83\u0abc\u0abe-\u0ac5\u0ac7-\u0ac9\u0acb-\u0acd\u0ae2\u0ae3\u0ae6-\u0aef\u0afa-\u0aff\u0b01-\u0b03\u0b3c\u0b3e-\u0b44\u0b47\u0b48\u0b4b-\u0b4d\u0b55-\u0b57\u0b62\u0b63\u0b66-\u0b6f\u0b82\u0bbe-\u0bc2\u0bc6-\u0bc8\u0bca-\u0bcd\u0bd7\u0be6-\u0bef\u0c00-\u0c04\u0c3e-\u0c44\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62\u0c63\u0c66-\u0c6f\u0c81-\u0c83\u0cbc\u0cbe-\u0cc4\u0cc6-\u0cc8\u0cca-\u0ccd\u0cd5\u0cd6\u0ce2\u0ce3\u0ce6-\u0cef\u0d00-\u0d03\u0d3b\u0d3c\u0d3e-\u0d44\u0d46-\u0d48\u0d4a-\u0d4d\u0d57\u0d62\u0d63\u0d66-\u0d6f\u0d81-\u0d83\u0dca\u0dcf-\u0dd4\u0dd6\u0dd8-\u0ddf\u0de6-\u0def\u0df2\u0df3\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0e50-\u0e59\u0eb1\u0eb4-\u0ebc\u0ec8-\u0ecd\u0ed0-\u0ed9\u0f18\u0f19\u0f20-\u0f29\u0f35\u0f37\u0f39\u0f3e\u0f3f\u0f71-\u0f84\u0f86\u0f87\u0f8d-\u0f97\u0f99-\u0fbc\u0fc6\u102b-\u103e\u1040-\u1049\u1056-\u1059\u105e-\u1060\u1062-\u1064\u1067-\u106d\u1071-\u1074\u1082-\u108d\u108f-\u109d\u135d-\u135f\u1369-\u1371\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17b4-\u17d3\u17dd\u17e0-\u17e9\u180b-\u180d\u1810-\u1819\u18a9\u1920-\u192b\u1930-\u193b\u1946-\u194f\u19d0-\u19da\u1a17-\u1a1b\u1a55-\u1a5e\u1a60-\u1a7c\u1a7f-\u1a89\u1a90-\u1a99\u1ab0-\u1abd\u1abf\u1ac0\u1b00-\u1b04\u1b34-\u1b44\u1b50-\u1b59\u1b6b-\u1b73\u1b80-\u1b82\u1ba1-\u1bad\u1bb0-\u1bb9\u1be6-\u1bf3\u1c24-\u1c37\u1c40-\u1c49\u1c50-\u1c59\u1cd0-\u1cd2\u1cd4-\u1ce8\u1ced\u1cf4\u1cf7-\u1cf9\u1dc0-\u1df9\u1dfb-\u1dff\u203f\u2040\u2054\u20d0-\u20dc\u20e1\u20e5-\u20f0\u2cef-\u2cf1\u2d7f\u2de0-\u2dff\u302a-\u302f\u3099\u309a\ua620-\ua629\ua66f\ua674-\ua67d\ua69e\ua69f\ua6f0\ua6f1\ua802\ua806\ua80b\ua823-\ua827\ua82c\ua880\ua881\ua8b4-\ua8c5\ua8d0-\ua8d9\ua8e0-\ua8f1\ua8ff-\ua909\ua926-\ua92d\ua947-\ua953\ua980-\ua983\ua9b3-\ua9c0\ua9d0-\ua9d9\ua9e5\ua9f0-\ua9f9\uaa29-\uaa36\uaa43\uaa4c\uaa4d\uaa50-\uaa59\uaa7b-\uaa7d\uaab0\uaab2-\uaab4\uaab7\uaab8\uaabe\uaabf\uaac1\uaaeb-\uaaef\uaaf5\uaaf6\uabe3-\uabea\uabec\uabed\uabf0-\uabf9\ufb1e\ufe00-\ufe0f\ufe20-\ufe2f\ufe33\ufe34\ufe4d-\ufe4f\uff10-\uff19\uff3f"
 
 const nonASCIIidentifierStart = new RegExp("[" + nonASCIIidentifierStartChars + "]")
 const nonASCIIidentifier = new RegExp("[" + nonASCIIidentifierStartChars + nonASCIIidentifierChars + "]")
@@ -42,10 +42,10 @@ nonASCIIidentifierStartChars = nonASCIIidentifierChars = null
 // generated by bin/generate-identifier-regex.js
 
 // eslint-disable-next-line comma-spacing
-const astralIdentifierStartCodes = [0,11,2,25,2,18,2,1,2,14,3,13,35,122,70,52,268,28,4,48,48,31,14,29,6,37,11,29,3,35,5,7,2,4,43,157,19,35,5,35,5,39,9,51,157,310,10,21,11,7,153,5,3,0,2,43,2,1,4,0,3,22,11,22,10,30,66,18,2,1,11,21,11,25,71,55,7,1,65,0,16,3,2,2,2,28,43,28,4,28,36,7,2,27,28,53,11,21,11,18,14,17,111,72,56,50,14,50,14,35,477,28,11,0,9,21,155,22,13,52,76,44,33,24,27,35,30,0,12,34,4,0,13,47,15,3,22,0,2,0,36,17,2,24,85,6,2,0,2,3,2,14,2,9,8,46,39,7,3,1,3,21,2,6,2,1,2,4,4,0,19,0,13,4,159,52,19,3,21,0,33,47,21,1,2,0,185,46,42,3,37,47,21,0,60,42,14,0,72,26,230,43,117,63,32,0,161,7,3,38,17,0,2,0,29,0,11,39,8,0,22,0,12,45,20,0,35,56,264,8,2,36,18,0,50,29,113,6,2,1,2,37,22,0,26,5,2,1,2,31,15,0,328,18,270,921,103,110,18,195,2749,1070,4050,582,8634,568,8,30,114,29,19,47,17,3,32,20,6,18,689,63,129,74,6,0,67,12,65,1,2,0,29,6135,9,754,9486,286,50,2,18,3,9,395,2309,106,6,12,4,8,8,9,5991,84,2,70,2,1,3,0,3,1,3,3,2,11,2,0,2,6,2,64,2,3,3,7,2,6,2,27,2,3,2,4,2,0,4,6,2,339,3,24,2,24,2,30,2,24,2,30,2,24,2,30,2,24,2,30,2,24,2,7,2357,44,11,6,17,0,370,43,1301,196,60,67,8,0,1205,3,2,26,2,1,2,0,3,0,2,9,2,3,2,0,2,0,7,0,5,0,2,0,2,0,2,2,2,1,2,0,3,0,2,0,2,0,2,0,2,0,2,1,2,0,3,3,2,6,2,3,2,3,2,0,2,9,2,16,6,2,2,4,2,16,4421,42710,42,4148,12,221,3,5761,15,7472,3104,541]
+const astralIdentifierStartCodes = [0,11,2,25,2,18,2,1,2,14,3,13,35,122,70,52,268,28,4,48,48,31,14,29,6,37,11,29,3,35,5,7,2,4,43,157,19,35,5,35,5,39,9,51,157,310,10,21,11,7,153,5,3,0,2,43,2,1,4,0,3,22,11,22,10,30,66,18,2,1,11,21,11,25,71,55,7,1,65,0,16,3,2,2,2,28,43,28,4,28,36,7,2,27,28,53,11,21,11,18,14,17,111,72,56,50,14,50,14,35,349,41,7,1,79,28,11,0,9,21,107,20,28,22,13,52,76,44,33,24,27,35,30,0,3,0,9,34,4,0,13,47,15,3,22,0,2,0,36,17,2,24,85,6,2,0,2,3,2,14,2,9,8,46,39,7,3,1,3,21,2,6,2,1,2,4,4,0,19,0,13,4,159,52,19,3,21,2,31,47,21,1,2,0,185,46,42,3,37,47,21,0,60,42,14,0,72,26,230,43,117,63,32,7,3,0,3,7,2,1,2,23,16,0,2,0,95,7,3,38,17,0,2,0,29,0,11,39,8,0,22,0,12,45,20,0,35,56,264,8,2,36,18,0,50,29,113,6,2,1,2,37,22,0,26,5,2,1,2,31,15,0,328,18,190,0,80,921,103,110,18,195,2749,1070,4050,582,8634,568,8,30,114,29,19,47,17,3,32,20,6,18,689,63,129,74,6,0,67,12,65,1,2,0,29,6135,9,1237,43,8,8952,286,50,2,18,3,9,395,2309,106,6,12,4,8,8,9,5991,84,2,70,2,1,3,0,3,1,3,3,2,11,2,0,2,6,2,64,2,3,3,7,2,6,2,27,2,3,2,4,2,0,4,6,2,339,3,24,2,24,2,30,2,24,2,30,2,24,2,30,2,24,2,30,2,24,2,7,2357,44,11,6,17,0,370,43,1301,196,60,67,8,0,1205,3,2,26,2,1,2,0,3,0,2,9,2,3,2,0,2,0,7,0,5,0,2,0,2,0,2,2,2,1,2,0,3,0,2,0,2,0,2,0,2,0,2,1,2,0,3,3,2,6,2,3,2,3,2,0,2,9,2,16,6,2,2,4,2,16,4421,42717,35,4148,12,221,3,5761,15,7472,3104,541,1507,4938]
 
 // eslint-disable-next-line comma-spacing
-const astralIdentifierCodes = [509,0,227,0,150,4,294,9,1368,2,2,1,6,3,41,2,5,0,166,1,574,3,9,9,525,10,176,2,54,14,32,9,16,3,46,10,54,9,7,2,37,13,2,9,6,1,45,0,13,2,49,13,9,3,4,9,83,11,7,0,161,11,6,9,7,3,56,1,2,6,3,1,3,2,10,0,11,1,3,6,4,4,193,17,10,9,5,0,82,19,13,9,214,6,3,8,28,1,83,16,16,9,82,12,9,9,84,14,5,9,243,14,166,9,232,6,3,6,4,0,29,9,41,6,2,3,9,0,10,10,47,15,406,7,2,7,17,9,57,21,2,13,123,5,4,0,2,1,2,6,2,0,9,9,49,4,2,1,2,4,9,9,330,3,19306,9,135,4,60,6,26,9,1014,0,2,54,8,3,19723,1,5319,4,4,5,9,7,3,6,31,3,149,2,1418,49,513,54,5,49,9,0,15,0,23,4,2,14,1361,6,2,16,3,6,2,1,2,4,262,6,10,9,419,13,1495,6,110,6,6,9,792487,239]
+const astralIdentifierCodes = [509,0,227,0,150,4,294,9,1368,2,2,1,6,3,41,2,5,0,166,1,574,3,9,9,370,1,154,10,176,2,54,14,32,9,16,3,46,10,54,9,7,2,37,13,2,9,6,1,45,0,13,2,49,13,9,3,2,11,83,11,7,0,161,11,6,9,7,3,56,1,2,6,3,1,3,2,10,0,11,1,3,6,4,4,193,17,10,9,5,0,82,19,13,9,214,6,3,8,28,1,83,16,16,9,82,12,9,9,84,14,5,9,243,14,166,9,71,5,2,1,3,3,2,0,2,1,13,9,120,6,3,6,4,0,29,9,41,6,2,3,9,0,10,10,47,15,406,7,2,7,17,9,57,21,2,13,123,5,4,0,2,1,2,6,2,0,9,9,49,4,2,1,2,4,9,9,330,3,19306,9,135,4,60,6,26,9,1014,0,2,54,8,3,82,0,12,1,19628,1,5319,4,4,5,9,7,3,6,31,3,149,2,1418,49,513,54,5,49,9,0,15,0,23,4,2,14,1361,6,2,16,3,6,2,1,2,4,262,6,10,9,419,13,1495,6,110,6,6,9,4759,9,787719,239]
 
 // This has a complexity linear to the value of the code. The
 // assumption is that looking up astral identifier characters is
diff --git a/acorn/src/index.js b/acorn/src/index.js
index f466a3b9f..eb118534b 100644
--- a/acorn/src/index.js
+++ b/acorn/src/index.js
@@ -31,7 +31,7 @@ import {isIdentifierChar, isIdentifierStart} from "./identifier"
 import {Token} from "./tokenize"
 import {isNewLine, lineBreak, lineBreakG, nonASCIIwhitespace} from "./whitespace"
 
-export const version = "7.1.0"
+export const version = "7.4.0"
 export {
   Parser,
   defaultOptions,
diff --git a/acorn/src/lval.js b/acorn/src/lval.js
index 8ad4b2639..03b3ce8c6 100644
--- a/acorn/src/lval.js
+++ b/acorn/src/lval.js
@@ -73,6 +73,10 @@ pp.toAssignable = function(node, isBinding, refDestructuringErrors) {
       this.toAssignable(node.expression, isBinding, refDestructuringErrors)
       break
 
+    case "ChainExpression":
+      this.raiseRecoverable(node.start, "Optional chaining cannot appear in left-hand side")
+      break
+
     case "MemberExpression":
       if (!isBinding) break
 
@@ -201,6 +205,10 @@ pp.checkLVal = function(expr, bindingType = BIND_NONE, checkClashes) {
     if (bindingType !== BIND_NONE && bindingType !== BIND_OUTSIDE) this.declareName(expr.name, bindingType, expr.start)
     break
 
+  case "ChainExpression":
+    this.raiseRecoverable(expr.start, "Optional chaining cannot appear in left-hand side")
+    break
+
   case "MemberExpression":
     if (bindingType) this.raiseRecoverable(expr.start, "Binding member expression")
     break
diff --git a/acorn/src/parseutil.js b/acorn/src/parseutil.js
index bce71b54e..98e35237f 100644
--- a/acorn/src/parseutil.js
+++ b/acorn/src/parseutil.js
@@ -14,7 +14,14 @@ pp.strictDirective = function(start) {
     start += skipWhiteSpace.exec(this.input)[0].length
     let match = literal.exec(this.input.slice(start))
     if (!match) return false
-    if ((match[1] || match[2]) === "use strict") return true
+    if ((match[1] || match[2]) === "use strict") {
+      skipWhiteSpace.lastIndex = start + match[0].length
+      let spaceAfter = skipWhiteSpace.exec(this.input), end = spaceAfter.index + spaceAfter[0].length
+      let next = this.input.charAt(end)
+      return next === ";" || next === "}" ||
+        (lineBreak.test(spaceAfter[0]) &&
+         !(/[(`.[+\-/*%<>=,?^&]/.test(next) || next === "!" && this.input.charAt(end + 1) === "="))
+    }
     start += match[0].length
 
     // Skip semicolon, if any.
diff --git a/acorn/src/regexp.js b/acorn/src/regexp.js
index ee19bcf55..d0e66df83 100644
--- a/acorn/src/regexp.js
+++ b/acorn/src/regexp.js
@@ -40,47 +40,49 @@ export class RegExpValidationState {
 
   // If u flag is given, this returns the code point at the index (it combines a surrogate pair).
   // Otherwise, this returns the code unit of the index (can be a part of a surrogate pair).
-  at(i) {
+  at(i, forceU = false) {
     const s = this.source
     const l = s.length
     if (i >= l) {
       return -1
     }
     const c = s.charCodeAt(i)
-    if (!this.switchU || c <= 0xD7FF || c >= 0xE000 || i + 1 >= l) {
+    if (!(forceU || this.switchU) || c <= 0xD7FF || c >= 0xE000 || i + 1 >= l) {
       return c
     }
-    return (c << 10) + s.charCodeAt(i + 1) - 0x35FDC00
+    const next = s.charCodeAt(i + 1)
+    return next >= 0xDC00 && next <= 0xDFFF ? (c << 10) + next - 0x35FDC00 : c
   }
 
-  nextIndex(i) {
+  nextIndex(i, forceU = false) {
     const s = this.source
     const l = s.length
     if (i >= l) {
       return l
     }
-    const c = s.charCodeAt(i)
-    if (!this.switchU || c <= 0xD7FF || c >= 0xE000 || i + 1 >= l) {
+    let c = s.charCodeAt(i), next
+    if (!(forceU || this.switchU) || c <= 0xD7FF || c >= 0xE000 || i + 1 >= l ||
+        (next = s.charCodeAt(i + 1)) < 0xDC00 || next > 0xDFFF) {
       return i + 1
     }
     return i + 2
   }
 
-  current() {
-    return this.at(this.pos)
+  current(forceU = false) {
+    return this.at(this.pos, forceU)
   }
 
-  lookahead() {
-    return this.at(this.nextIndex(this.pos))
+  lookahead(forceU = false) {
+    return this.at(this.nextIndex(this.pos, forceU), forceU)
   }
 
-  advance() {
-    this.pos = this.nextIndex(this.pos)
+  advance(forceU = false) {
+    this.pos = this.nextIndex(this.pos, forceU)
   }
 
-  eat(ch) {
-    if (this.current() === ch) {
-      this.advance()
+  eat(ch, forceU = false) {
+    if (this.current(forceU) === ch) {
+      this.advance(forceU)
       return true
     }
     return false
@@ -152,7 +154,7 @@ pp.regexp_pattern = function(state) {
     if (state.eat(0x29 /* ) */)) {
       state.raise("Unmatched ')'")
     }
-    if (state.eat(0x5D /* [ */) || state.eat(0x7D /* } */)) {
+    if (state.eat(0x5D /* ] */) || state.eat(0x7D /* } */)) {
       state.raise("Lone quantifier brackets")
     }
   }
@@ -416,9 +418,9 @@ pp.regexp_eatExtendedPatternCharacter = function(state) {
   return false
 }
 
-// GroupSpecifier[U] ::
+// GroupSpecifier ::
 //   [empty]
-//   `?` GroupName[?U]
+//   `?` GroupName
 pp.regexp_groupSpecifier = function(state) {
   if (state.eat(0x3F /* ? */)) {
     if (this.regexp_eatGroupName(state)) {
@@ -432,8 +434,8 @@ pp.regexp_groupSpecifier = function(state) {
   }
 }
 
-// GroupName[U] ::
-//   `<` RegExpIdentifierName[?U] `>`
+// GroupName ::
+//   `<` RegExpIdentifierName `>`
 // Note: this updates `state.lastStringValue` property with the eaten name.
 pp.regexp_eatGroupName = function(state) {
   state.lastStringValue = ""
@@ -446,9 +448,9 @@ pp.regexp_eatGroupName = function(state) {
   return false
 }
 
-// RegExpIdentifierName[U] ::
-//   RegExpIdentifierStart[?U]
-//   RegExpIdentifierName[?U] RegExpIdentifierPart[?U]
+// RegExpIdentifierName ::
+//   RegExpIdentifierStart
+//   RegExpIdentifierName RegExpIdentifierPart
 // Note: this updates `state.lastStringValue` property with the eaten name.
 pp.regexp_eatRegExpIdentifierName = function(state) {
   state.lastStringValue = ""
@@ -462,17 +464,18 @@ pp.regexp_eatRegExpIdentifierName = function(state) {
   return false
 }
 
-// RegExpIdentifierStart[U] ::
+// RegExpIdentifierStart ::
 //   UnicodeIDStart
 //   `$`
 //   `_`
-//   `\` RegExpUnicodeEscapeSequence[?U]
+//   `\` RegExpUnicodeEscapeSequence[+U]
 pp.regexp_eatRegExpIdentifierStart = function(state) {
   const start = state.pos
-  let ch = state.current()
-  state.advance()
+  const forceU = this.options.ecmaVersion >= 11
+  let ch = state.current(forceU)
+  state.advance(forceU)
 
-  if (ch === 0x5C /* \ */ && this.regexp_eatRegExpUnicodeEscapeSequence(state)) {
+  if (ch === 0x5C /* \ */ && this.regexp_eatRegExpUnicodeEscapeSequence(state, forceU)) {
     ch = state.lastIntValue
   }
   if (isRegExpIdentifierStart(ch)) {
@@ -487,19 +490,20 @@ function isRegExpIdentifierStart(ch) {
   return isIdentifierStart(ch, true) || ch === 0x24 /* $ */ || ch === 0x5F /* _ */
 }
 
-// RegExpIdentifierPart[U] ::
+// RegExpIdentifierPart ::
 //   UnicodeIDContinue
 //   `$`
 //   `_`
-//   `\` RegExpUnicodeEscapeSequence[?U]
+//   `\` RegExpUnicodeEscapeSequence[+U]
 //   <ZWNJ>
 //   <ZWJ>
 pp.regexp_eatRegExpIdentifierPart = function(state) {
   const start = state.pos
-  let ch = state.current()
-  state.advance()
+  const forceU = this.options.ecmaVersion >= 11
+  let ch = state.current(forceU)
+  state.advance(forceU)
 
-  if (ch === 0x5C /* \ */ && this.regexp_eatRegExpUnicodeEscapeSequence(state)) {
+  if (ch === 0x5C /* \ */ && this.regexp_eatRegExpUnicodeEscapeSequence(state, forceU)) {
     ch = state.lastIntValue
   }
   if (isRegExpIdentifierPart(ch)) {
@@ -569,7 +573,7 @@ pp.regexp_eatCharacterEscape = function(state) {
     this.regexp_eatCControlLetter(state) ||
     this.regexp_eatZero(state) ||
     this.regexp_eatHexEscapeSequence(state) ||
-    this.regexp_eatRegExpUnicodeEscapeSequence(state) ||
+    this.regexp_eatRegExpUnicodeEscapeSequence(state, false) ||
     (!state.switchU && this.regexp_eatLegacyOctalEscapeSequence(state)) ||
     this.regexp_eatIdentityEscape(state)
   )
@@ -642,13 +646,14 @@ function isControlLetter(ch) {
 }
 
 // https://www.ecma-international.org/ecma-262/8.0/#prod-RegExpUnicodeEscapeSequence
-pp.regexp_eatRegExpUnicodeEscapeSequence = function(state) {
+pp.regexp_eatRegExpUnicodeEscapeSequence = function(state, forceU = false) {
   const start = state.pos
+  const switchU = forceU || state.switchU
 
   if (state.eat(0x75 /* u */)) {
     if (this.regexp_eatFixedHexDigits(state, 4)) {
       const lead = state.lastIntValue
-      if (state.switchU && lead >= 0xD800 && lead <= 0xDBFF) {
+      if (switchU && lead >= 0xD800 && lead <= 0xDBFF) {
         const leadSurrogateEnd = state.pos
         if (state.eat(0x5C /* \ */) && state.eat(0x75 /* u */) && this.regexp_eatFixedHexDigits(state, 4)) {
           const trail = state.lastIntValue
@@ -663,7 +668,7 @@ pp.regexp_eatRegExpUnicodeEscapeSequence = function(state) {
       return true
     }
     if (
-      state.switchU &&
+      switchU &&
       state.eat(0x7B /* { */) &&
       this.regexp_eatHexDigits(state) &&
       state.eat(0x7D /* } */) &&
@@ -671,7 +676,7 @@ pp.regexp_eatRegExpUnicodeEscapeSequence = function(state) {
     ) {
       return true
     }
-    if (state.switchU) {
+    if (switchU) {
       state.raise("Invalid unicode escape")
     }
     state.pos = start
@@ -837,7 +842,7 @@ pp.regexp_eatCharacterClass = function(state) {
   if (state.eat(0x5B /* [ */)) {
     state.eat(0x5E /* ^ */)
     this.regexp_classRanges(state)
-    if (state.eat(0x5D /* [ */)) {
+    if (state.eat(0x5D /* ] */)) {
       return true
     }
     // Unreachable since it threw "unterminated regular expression" error before.
@@ -885,7 +890,7 @@ pp.regexp_eatClassAtom = function(state) {
   }
 
   const ch = state.current()
-  if (ch !== 0x5D /* [ */) {
+  if (ch !== 0x5D /* ] */) {
     state.lastIntValue = ch
     state.advance()
     return true
diff --git a/acorn/src/statement.js b/acorn/src/statement.js
index 8cadb5118..4afea7503 100644
--- a/acorn/src/statement.js
+++ b/acorn/src/statement.js
@@ -122,7 +122,7 @@ pp.parseStatement = function(context, topLevel, exports) {
       skipWhiteSpace.lastIndex = this.pos
       let skip = skipWhiteSpace.exec(this.input)
       let next = this.pos + skip[0].length, nextCh = this.input.charCodeAt(next)
-      if (nextCh === 40) // '('
+      if (nextCh === 40 || nextCh === 46) // '(' or '.'
         return this.parseExpressionStatement(node, this.parseExpression())
     }
 
@@ -418,14 +418,16 @@ pp.parseExpressionStatement = function(node, expr) {
 // strict"` declarations when `allowStrict` is true (used for
 // function bodies).
 
-pp.parseBlock = function(createNewLexicalScope = true, node = this.startNode()) {
+pp.parseBlock = function(createNewLexicalScope = true, node = this.startNode(), exitStrict) {
   node.body = []
   this.expect(tt.braceL)
   if (createNewLexicalScope) this.enterScope(0)
-  while (!this.eat(tt.braceR)) {
+  while (this.type !== tt.braceR) {
     let stmt = this.parseStatement(null)
     node.body.push(stmt)
   }
+  if (exitStrict) this.strict = false
+  this.next()
   if (createNewLexicalScope) this.exitScope()
   return this.finishNode(node, "BlockStatement")
 }
@@ -578,7 +580,7 @@ pp.parseClass = function(node, isStatement) {
   let hadConstructor = false
   classBody.body = []
   this.expect(tt.braceL)
-  while (!this.eat(tt.braceR)) {
+  while (this.type !== tt.braceR) {
     const element = this.parseClassElement(node.superClass !== null)
     if (element) {
       classBody.body.push(element)
@@ -588,8 +590,9 @@ pp.parseClass = function(node, isStatement) {
       }
     }
   }
-  node.body = this.finishNode(classBody, "ClassBody")
   this.strict = oldStrict
+  this.next()
+  node.body = this.finishNode(classBody, "ClassBody")
   return this.finishNode(node, isStatement ? "ClassDeclaration" : "ClassExpression")
 }
 
@@ -673,6 +676,14 @@ pp.parseExport = function(node, exports) {
   this.next()
   // export * from '...'
   if (this.eat(tt.star)) {
+    if (this.options.ecmaVersion >= 11) {
+      if (this.eatContextual("as")) {
+        node.exported = this.parseIdent(true)
+        this.checkExport(exports, node.exported.name, this.lastTokStart)
+      } else {
+        node.exported = null
+      }
+    }
     this.expectContextual("from")
     if (this.type !== tt.string) this.unexpected()
     node.source = this.parseExprAtom()
diff --git a/acorn/src/tokenize.js b/acorn/src/tokenize.js
index f9f6b2f6f..6c86f5c51 100644
--- a/acorn/src/tokenize.js
+++ b/acorn/src/tokenize.js
@@ -28,7 +28,9 @@ const pp = Parser.prototype
 
 // Move to the next token
 
-pp.next = function() {
+pp.next = function(ignoreEscapeSequenceInKeyword) {
+  if (!ignoreEscapeSequenceInKeyword && this.type.keyword && this.containsEsc)
+    this.raiseRecoverable(this.start, "Escape sequence in keyword " + this.type.keyword)
   if (this.options.onToken)
     this.options.onToken(new Token(this))
 
@@ -231,7 +233,13 @@ pp.readToken_mult_modulo_exp = function(code) { // '%*'
 
 pp.readToken_pipe_amp = function(code) { // '|&'
   let next = this.input.charCodeAt(this.pos + 1)
-  if (next === code) return this.finishOp(code === 124 ? tt.logicalOR : tt.logicalAND, 2)
+  if (next === code) {
+    if (this.options.ecmaVersion >= 12) {
+      let next2 = this.input.charCodeAt(this.pos + 2)
+      if (next2 === 61) return this.finishOp(tt.assign, 3)
+    }
+    return this.finishOp(code === 124 ? tt.logicalOR : tt.logicalAND, 2)
+  }
   if (next === 61) return this.finishOp(tt.assign, 2)
   return this.finishOp(code === 124 ? tt.bitwiseOR : tt.bitwiseAND, 1)
 }
@@ -287,6 +295,25 @@ pp.readToken_eq_excl = function(code) { // '=!'
   return this.finishOp(code === 61 ? tt.eq : tt.prefix, 1)
 }
 
+pp.readToken_question = function() { // '?'
+  const ecmaVersion = this.options.ecmaVersion
+  if (ecmaVersion >= 11) {
+    let next = this.input.charCodeAt(this.pos + 1)
+    if (next === 46) {
+      let next2 = this.input.charCodeAt(this.pos + 2)
+      if (next2 < 48 || next2 > 57) return this.finishOp(tt.questionDot, 2)
+    }
+    if (next === 63) {
+      if (ecmaVersion >= 12) {
+        let next2 = this.input.charCodeAt(this.pos + 2)
+        if (next2 === 61) return this.finishOp(tt.assign, 3)
+      }
+      return this.finishOp(tt.coalesce, 2)
+    }
+  }
+  return this.finishOp(tt.question, 1)
+}
+
 pp.getTokenFromCode = function(code) {
   switch (code) {
   // The interpretation of a dot depends on whether it is followed
@@ -304,7 +331,6 @@ pp.getTokenFromCode = function(code) {
   case 123: ++this.pos; return this.finishToken(tt.braceL)
   case 125: ++this.pos; return this.finishToken(tt.braceR)
   case 58: ++this.pos; return this.finishToken(tt.colon)
-  case 63: ++this.pos; return this.finishToken(tt.question)
 
   case 96: // '`'
     if (this.options.ecmaVersion < 6) break
@@ -354,6 +380,9 @@ pp.getTokenFromCode = function(code) {
   case 61: case 33: // '=!'
     return this.readToken_eq_excl(code)
 
+  case 63: // '?'
+    return this.readToken_question()
+
   case 126: // '~'
     return this.finishOp(tt.prefix, 1)
   }
@@ -409,30 +438,67 @@ pp.readRegexp = function() {
 // were read, the integer value otherwise. When `len` is given, this
 // will return `null` unless the integer has exactly `len` digits.
 
-pp.readInt = function(radix, len) {
-  let start = this.pos, total = 0
-  for (let i = 0, e = len == null ? Infinity : len; i < e; ++i) {
+pp.readInt = function(radix, len, maybeLegacyOctalNumericLiteral) {
+  // `len` is used for character escape sequences. In that case, disallow separators.
+  const allowSeparators = this.options.ecmaVersion >= 12 && len === undefined
+
+  // `maybeLegacyOctalNumericLiteral` is true if it doesn't have prefix (0x,0o,0b)
+  // and isn't fraction part nor exponent part. In that case, if the first digit
+  // is zero then disallow separators.
+  const isLegacyOctalNumericLiteral = maybeLegacyOctalNumericLiteral && this.input.charCodeAt(this.pos) === 48
+
+  let start = this.pos, total = 0, lastCode = 0
+  for (let i = 0, e = len == null ? Infinity : len; i < e; ++i, ++this.pos) {
     let code = this.input.charCodeAt(this.pos), val
+
+    if (allowSeparators && code === 95) {
+      if (isLegacyOctalNumericLiteral) this.raiseRecoverable(this.pos, "Numeric separator is not allowed in legacy octal numeric literals")
+      if (lastCode === 95) this.raiseRecoverable(this.pos, "Numeric separator must be exactly one underscore")
+      if (i === 0) this.raiseRecoverable(this.pos, "Numeric separator is not allowed at the first of digits")
+      lastCode = code
+      continue
+    }
+
     if (code >= 97) val = code - 97 + 10 // a
     else if (code >= 65) val = code - 65 + 10 // A
     else if (code >= 48 && code <= 57) val = code - 48 // 0-9
     else val = Infinity
     if (val >= radix) break
-    ++this.pos
+    lastCode = code
     total = total * radix + val
   }
+
+  if (allowSeparators && lastCode === 95) this.raiseRecoverable(this.pos - 1, "Numeric separator is not allowed at the last of digits")
   if (this.pos === start || len != null && this.pos - start !== len) return null
 
   return total
 }
 
+function stringToNumber(str, isLegacyOctalNumericLiteral) {
+  if (isLegacyOctalNumericLiteral) {
+    return parseInt(str, 8)
+  }
+
+  // `parseFloat(value)` stops parsing at the first numeric separator then returns a wrong value.
+  return parseFloat(str.replace(/_/g, ""))
+}
+
+function stringToBigInt(str) {
+  if (typeof BigInt !== "function") {
+    return null
+  }
+
+  // `BigInt(value)` throws syntax error if the string contains numeric separators.
+  return BigInt(str.replace(/_/g, ""))
+}
+
 pp.readRadixNumber = function(radix) {
   let start = this.pos
   this.pos += 2 // 0x
   let val = this.readInt(radix)
   if (val == null) this.raise(this.start + 2, "Expected number in radix " + radix)
   if (this.options.ecmaVersion >= 11 && this.input.charCodeAt(this.pos) === 110) {
-    val = typeof BigInt !== "undefined" ? BigInt(this.input.slice(start, this.pos)) : null
+    val = stringToBigInt(this.input.slice(start, this.pos))
     ++this.pos
   } else if (isIdentifierStart(this.fullCharCodeAtPos())) this.raise(this.pos, "Identifier directly after number")
   return this.finishToken(tt.num, val)
@@ -442,18 +508,17 @@ pp.readRadixNumber = function(radix) {
 
 pp.readNumber = function(startsWithDot) {
   let start = this.pos
-  if (!startsWithDot && this.readInt(10) === null) this.raise(start, "Invalid number")
+  if (!startsWithDot && this.readInt(10, undefined, true) === null) this.raise(start, "Invalid number")
   let octal = this.pos - start >= 2 && this.input.charCodeAt(start) === 48
   if (octal && this.strict) this.raise(start, "Invalid number")
-  if (octal && /[89]/.test(this.input.slice(start, this.pos))) octal = false
   let next = this.input.charCodeAt(this.pos)
   if (!octal && !startsWithDot && this.options.ecmaVersion >= 11 && next === 110) {
-    let str = this.input.slice(start, this.pos)
-    let val = typeof BigInt !== "undefined" ? BigInt(str) : null
+    let val = stringToBigInt(this.input.slice(start, this.pos))
     ++this.pos
     if (isIdentifierStart(this.fullCharCodeAtPos())) this.raise(this.pos, "Identifier directly after number")
     return this.finishToken(tt.num, val)
   }
+  if (octal && /[89]/.test(this.input.slice(start, this.pos))) octal = false
   if (next === 46 && !octal) { // '.'
     ++this.pos
     this.readInt(10)
@@ -466,8 +531,7 @@ pp.readNumber = function(startsWithDot) {
   }
   if (isIdentifierStart(this.fullCharCodeAtPos())) this.raise(this.pos, "Identifier directly after number")
 
-  let str = this.input.slice(start, this.pos)
-  let val = octal ? parseInt(str, 8) : parseFloat(str)
+  let val = stringToNumber(this.input.slice(start, this.pos), octal)
   return this.finishToken(tt.num, val)
 }
 
@@ -628,6 +692,18 @@ pp.readEscapedChar = function(inTemplate) {
   case 10: // ' \n'
     if (this.options.locations) { this.lineStart = this.pos; ++this.curLine }
     return ""
+  case 56:
+  case 57:
+    if (inTemplate) {
+      const codePos = this.pos - 1
+
+      this.invalidStringToken(
+        codePos,
+        "Invalid escape sequence in template string"
+      )
+
+      return null
+    }
   default:
     if (ch >= 48 && ch <= 55) {
       let octalStr = this.input.substr(this.pos - 1, 3).match(/^[0-7]+/)[0]
@@ -707,7 +783,6 @@ pp.readWord = function() {
   let word = this.readWord1()
   let type = tt.name
   if (this.keywords.test(word)) {
-    if (this.containsEsc) this.raiseRecoverable(this.start, "Escape sequence in keyword " + word)
     type = keywordTypes[word]
   }
   return this.finishToken(type, word)
diff --git a/acorn/src/tokentype.js b/acorn/src/tokentype.js
index 7a8c48a6d..1e821ff40 100644
--- a/acorn/src/tokentype.js
+++ b/acorn/src/tokentype.js
@@ -70,6 +70,7 @@ export const types = {
   colon: new TokenType(":", beforeExpr),
   dot: new TokenType("."),
   question: new TokenType("?", beforeExpr),
+  questionDot: new TokenType("?."),
   arrow: new TokenType("=>", beforeExpr),
   template: new TokenType("template"),
   invalidTemplate: new TokenType("invalidTemplate"),
@@ -108,6 +109,7 @@ export const types = {
   star: binop("*", 10),
   slash: binop("/", 10),
   starstar: new TokenType("**", {beforeExpr: true}),
+  coalesce: binop("??", 1),
 
   // Keyword token types.
   _break: kw("break"),
diff --git a/bin/run_test262.js b/bin/run_test262.js
index c540507d7..ff55bcd19 100644
--- a/bin/run_test262.js
+++ b/bin/run_test262.js
@@ -10,16 +10,17 @@ const unsupportedFeatures = [
   "class-static-fields-private",
   "class-static-fields-public",
   "class-static-methods-private",
-  "export-star-as-namespace-from-module",
-  "import.meta",
-  "numeric-separator-literal"
+  "logical-assignment-operators",
 ];
 
 run(
-  (content, {sourceType}) => parse(content, {sourceType, ecmaVersion: 11, allowHashBang: true}),
+  (content, {sourceType}) => parse(content, {sourceType, ecmaVersion: 12, allowHashBang: true, allowAwaitOutsideFunction: true}),
   {
     testsDirectory: path.dirname(require.resolve("test262/package.json")),
     skip: test => (test.attrs.features && unsupportedFeatures.some(f => test.attrs.features.includes(f))),
-    whitelist: fs.readFileSync("./bin/test262.whitelist", "utf8").split("\n").filter(v => v)
+    whitelist: fs.readFileSync("./bin/test262.whitelist", "utf8")
+      .split("\n")
+      .filter(Boolean)
+      .map(filename => path.sep !== "/" ? filename.split("/").join(path.sep) : filename)
   }
 )
diff --git a/bin/test262.whitelist b/bin/test262.whitelist
index e69de29bb..725858f89 100644
--- a/bin/test262.whitelist
+++ b/bin/test262.whitelist
@@ -0,0 +1,40 @@
+built-ins/RegExp/property-escapes/generated/Emoji_Component.js (default)
+built-ins/RegExp/property-escapes/generated/Emoji_Component.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Emoji_Modifier.js (default)
+built-ins/RegExp/property-escapes/generated/Emoji_Modifier.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Emoji_Modifier_Base.js (default)
+built-ins/RegExp/property-escapes/generated/Emoji_Modifier_Base.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Emoji_Presentation.js (default)
+built-ins/RegExp/property-escapes/generated/Emoji_Presentation.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Extended_Pictographic.js (default)
+built-ins/RegExp/property-escapes/generated/Extended_Pictographic.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Script_-_Chorasmian.js (default)
+built-ins/RegExp/property-escapes/generated/Script_-_Chorasmian.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Script_-_Dives_Akuru.js (default)
+built-ins/RegExp/property-escapes/generated/Script_-_Dives_Akuru.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Script_-_Khitan_Small_Script.js (default)
+built-ins/RegExp/property-escapes/generated/Script_-_Khitan_Small_Script.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Script_-_Yezidi.js (default)
+built-ins/RegExp/property-escapes/generated/Script_-_Yezidi.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Chorasmian.js (default)
+built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Chorasmian.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Dives_Akuru.js (default)
+built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Dives_Akuru.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Khitan_Small_Script.js (default)
+built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Khitan_Small_Script.js (strict mode)
+built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Yezidi.js (default)
+built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Yezidi.js (strict mode)
+
+language/literals/string/legacy-non-octal-escape-sequence-8-strict.js (strict mode)
+
+language/expressions/await/await-BindingIdentifier-in-global.js (default)
+language/expressions/await/await-BindingIdentifier-in-global.js (strict mode)
+language/expressions/await/await-in-global.js (default)
+language/expressions/await/await-in-global.js (strict mode)
+language/expressions/await/await-in-nested-function.js (default)
+language/expressions/await/await-in-nested-function.js (strict mode)
+language/expressions/await/await-in-nested-generator.js (default)
+language/expressions/await/await-in-nested-generator.js (strict mode)
+
+language/statements/labeled/value-await-non-module.js (default)
+language/statements/labeled/value-await-non-module.js (strict mode)
diff --git a/package.json b/package.json
index eb0dd1c73..382f59e0b 100644
--- a/package.json
+++ b/package.json
@@ -41,9 +41,9 @@
     "eslint-plugin-standard": "^3.0.1",
     "rollup": "^1.7.0",
     "rollup-plugin-buble": "^0.19.0",
-    "test262": "git+https://github.com/tc39/test262.git#de567d3aa5de4eaa11e00131d26b9fe77997dfb0",
+    "test262": "git+https://github.com/tc39/test262.git#a6c819ad0f049f23f1a37af6b89dbb79fe3b9216",
     "test262-parser-runner": "^0.5.0",
     "test262-stream": "^1.2.1",
-    "unicode-12.0.0": "^0.7.9"
+    "unicode-13.0.0": "^0.8.0"
   }
 }
diff --git a/test/run.js b/test/run.js
index 4ea981b90..80d3ad42d 100644
--- a/test/run.js
+++ b/test/run.js
@@ -12,10 +12,17 @@
   require("./tests-async-iteration.js");
   require("./tests-regexp.js");
   require("./tests-regexp-2018.js");
+  require("./tests-regexp-2020.js");
   require("./tests-json-superset.js");
   require("./tests-optional-catch-binding.js");
   require("./tests-bigint.js");
   require("./tests-dynamic-import.js");
+  require("./tests-export-all-as-ns-from-source.js");
+  require("./tests-import-meta.js");
+  require("./tests-nullish-coalescing.js");
+  require("./tests-optional-chaining.js");
+  require("./tests-logical-assignment-operators.js");
+  require("./tests-numeric-separators.js");
   var acorn = require("../acorn")
   var acorn_loose = require("../acorn-loose")
 
diff --git a/test/tests-asyncawait.js b/test/tests-asyncawait.js
index 77de3c8b8..f5d84794b 100644
--- a/test/tests-asyncawait.js
+++ b/test/tests-asyncawait.js
@@ -3523,3 +3523,7 @@ test(
 test("({ async delete() {} })", {}, {ecmaVersion: 8})
 
 testFail("abc: async function a() {}", "Unexpected token (1:5)", {ecmaVersion: 8})
+
+test("(async() => { await 4 ** 2 })()", {}, {ecmaVersion: 8})
+
+testFail("4 + async() => 2", "Unexpected token (1:12)", {ecmaVersion: 8, loose: false})
diff --git a/test/tests-dynamic-import.js b/test/tests-dynamic-import.js
index 675a45365..92e52586f 100644
--- a/test/tests-dynamic-import.js
+++ b/test/tests-dynamic-import.js
@@ -204,7 +204,7 @@ test(
   { ecmaVersion: 11 }
 );
 
-testFail('function failsParse() { return import.then(); }', 'Unexpected token (1:37)', {
+testFail('function failsParse() { return import.then(); }', 'The only valid meta property for import is \'import.meta\' (1:38)', {
   ecmaVersion: 11,
   loose: false
 });
diff --git a/test/tests-export-all-as-ns-from-source.js b/test/tests-export-all-as-ns-from-source.js
new file mode 100644
index 000000000..8a7145e71
--- /dev/null
+++ b/test/tests-export-all-as-ns-from-source.js
@@ -0,0 +1,93 @@
+
+if (typeof exports != "undefined") {
+  var driver = require("./driver.js");
+  var test = driver.test, testFail = driver.testFail;
+  var acorn = require("../acorn");
+}
+
+//------------------------------------------------------------------------------
+// export * as ns from "source"
+//------------------------------------------------------------------------------
+
+test("export * as ns from \"source\"", {
+  "type": "Program",
+  "start": 0,
+  "end": 28,
+  "body": [
+    {
+      "type": "ExportAllDeclaration",
+      "start": 0,
+      "end": 28,
+      "exported": {
+        "type": "Identifier",
+        "start": 12,
+        "end": 14,
+        "name": "ns"
+      },
+      "source": {
+        "type": "Literal",
+        "start": 20,
+        "end": 28,
+        "value": "source",
+        "raw": "\"source\""
+      }
+    }
+  ],
+  "sourceType": "module"
+}, { sourceType: "module", ecmaVersion: 11 })
+
+test("export * as foo from \"bar\"", {
+  "type": "Program",
+  "start": 0,
+  "end": 26,
+  "body": [
+    {
+      "type": "ExportAllDeclaration",
+      "start": 0,
+      "end": 26,
+      "exported": {
+        "type": "Identifier",
+        "start": 12,
+        "end": 15,
+        "name": "foo"
+      },
+      "source": {
+        "type": "Literal",
+        "start": 21,
+        "end": 26,
+        "value": "bar",
+        "raw": "\"bar\""
+      }
+    }
+  ],
+  "sourceType": "module"
+}, { sourceType: "module", ecmaVersion: 11 })
+
+test("export * from \"source\"", {
+  "type": "Program",
+  "start": 0,
+  "end": 22,
+  "body": [
+    {
+      "type": "ExportAllDeclaration",
+      "start": 0,
+      "end": 22,
+      "exported": null,
+      "source": {
+        "type": "Literal",
+        "start": 14,
+        "end": 22,
+        "value": "source",
+        "raw": "\"source\""
+      }
+    }
+  ],
+  "sourceType": "module"
+}, { sourceType: "module", ecmaVersion: 11 })
+
+testFail("export * as ns from \"source\"", "'import' and 'export' may appear only with 'sourceType: module' (1:0)", { sourceType: "script", ecmaVersion: 11 })
+testFail("export * as ns from \"source\"", "Unexpected token (1:9)", { sourceType: "module", ecmaVersion: 10 })
+testFail("export * as ns", "Unexpected token (1:14)", { sourceType: "module", ecmaVersion: 11 })
+testFail("export * as from \"source\"", "Unexpected token (1:17)", { sourceType: "module", ecmaVersion: 11 })
+testFail("export * as ns \"source\"", "Unexpected token (1:15)", { sourceType: "module", ecmaVersion: 11 })
+testFail("export {} as ns from \"source\"", "Unexpected token (1:10)", { sourceType: "module", ecmaVersion: 11 })
diff --git a/test/tests-harmony.js b/test/tests-harmony.js
index ade46a220..7b681e80c 100644
--- a/test/tests-harmony.js
+++ b/test/tests-harmony.js
@@ -14781,10 +14781,10 @@ test("function foo() { new.target; }", {
   sourceType: "script"
 }, {ecmaVersion: 6});
 
-testFail("new.prop", "The only valid meta property for new is new.target (1:4)", {ecmaVersion: 6});
-testFail("new.target", "new.target can only be used in functions (1:0)", {ecmaVersion: 6});
+testFail("new.prop", "The only valid meta property for new is 'new.target' (1:4)", {ecmaVersion: 6});
+testFail("new.target", "'new.target' can only be used in functions (1:0)", {ecmaVersion: 6});
 test("function x() { return () => new.target }", {}, {ecmaVersion: 6});
-testFail("let y = () => new.target", "new.target can only be used in functions (1:14)", {ecmaVersion: 6});
+testFail("let y = () => new.target", "'new.target' can only be used in functions (1:14)", {ecmaVersion: 6});
 
 test("export default function foo() {} false", {
   body: [
@@ -16512,3 +16512,63 @@ test("let x = 1; x = 2", {}, {ecmaVersion: 6})
 test("function *f2() { () => yield / 1 }", {}, {ecmaVersion: 6})
 
 test("({ a = 42, b: c.d } = e)", {}, {ecmaVersion: 6})
+
+testFail("({ a = 42, b: c = d })", "Shorthand property assignments are valid only in destructuring patterns (1:5)", {ecmaVersion: 6})
+
+test("({ __proto__: x, __proto__: y, __proto__: z }) => {}", {}, {ecmaVersion: 6})
+
+// Don't parse first token after a class or strict function as strict
+test("class x {}\n05", {}, {ecmaVersion: 6})
+test("function x() { 'use strict' }\n05", {}, {ecmaVersion: 6})
+
+test("const myFn = ({ set = '' }) => {};", {
+  "type": "Program",
+  "body": [
+    {
+      "type": "VariableDeclaration",
+      "declarations": [
+        {
+          "type": "VariableDeclarator",
+          "id": {
+            "type": "Identifier",
+            "name": "myFn"
+          },
+          "init": {
+            "type": "ArrowFunctionExpression",
+            "params": [
+              {
+                "type": "ObjectPattern",
+                "properties": [
+                  {
+                    "type": "Property",
+                    "key": {
+                      "type": "Identifier",
+                      "name": "set"
+                    },
+                    "kind": "init",
+                    "value": {
+                      "type": "AssignmentPattern",
+                      "left": {
+                        "type": "Identifier",
+                        "name": "set"
+                      },
+                      "right": {
+                        "type": "Literal",
+                        "value": ""
+                      }
+                    }
+                  }
+                ]
+              }
+            ],
+            "body": {
+              "type": "BlockStatement",
+              "body": []
+            }
+          }
+        }
+      ],
+      "kind": "const"
+    }
+  ]
+}, {ecmaVersion: 6})
diff --git a/test/tests-import-meta.js b/test/tests-import-meta.js
new file mode 100644
index 000000000..7f93d7a3a
--- /dev/null
+++ b/test/tests-import-meta.js
@@ -0,0 +1,97 @@
+// Tests for ECMAScript 2020 `import.meta`
+
+if (typeof exports != 'undefined') {
+  var test = require('./driver.js').test;
+  var testFail = require('./driver.js').testFail;
+}
+
+test(
+  "import.meta",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 11,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 11,
+        "expression": {
+          "type": "MetaProperty",
+          "start": 0,
+          "end": 11,
+          "meta": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 6,
+            "name": "import"
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 7,
+            "end": 11,
+            "name": "meta"
+          }
+        }
+      }
+    ],
+    "sourceType": "module"
+  },
+  { ecmaVersion: 11, sourceType: "module" }
+);
+
+test(
+  "import.meta.url",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 15,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 15,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 15,
+          "object": {
+            "type": "MetaProperty",
+            "start": 0,
+            "end": 11,
+            "meta": {
+              "type": "Identifier",
+              "start": 0,
+              "end": 6,
+              "name": "import"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 7,
+              "end": 11,
+              "name": "meta"
+            }
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 12,
+            "end": 15,
+            "name": "url"
+          },
+          "computed": false
+        }
+      }
+    ],
+    "sourceType": "module"
+  },
+  { ecmaVersion: 11, sourceType: "module" }
+);
+
+testFail("import.meta", "Unexpected token (1:6)", { ecmaVersion: 10, sourceType: "module" });
+testFail("import.meta", "Cannot use 'import.meta' outside a module (1:0)", { ecmaVersion: 11, sourceType: "script" });
+testFail("import['meta']", "Unexpected token (1:6)", { ecmaVersion: 11, sourceType: "module" });
+testFail("a = import['meta']", "Unexpected token (1:10)", { ecmaVersion: 11, sourceType: "module" });
+testFail("import.target", "The only valid meta property for import is 'import.meta' (1:7)", { ecmaVersion: 11, sourceType: "module" });
+testFail("new.meta", "The only valid meta property for new is 'new.target' (1:4)", { ecmaVersion: 11, sourceType: "module" });
+testFail("im\\u0070ort.meta", "Escape sequence in keyword import (1:0)", { ecmaVersion: 11, sourceType: "module" });
+testFail("import.\\u006d\\u0065\\u0074\\u0061", "'import.meta' must not contain escaped characters (1:0)", { ecmaVersion: 11, sourceType: "module" });
diff --git a/test/tests-logical-assignment-operators.js b/test/tests-logical-assignment-operators.js
new file mode 100644
index 000000000..2e157f019
--- /dev/null
+++ b/test/tests-logical-assignment-operators.js
@@ -0,0 +1,182 @@
+// Tests for ECMAScript 2021 `&&=`, `||=`, `??=`
+
+if (typeof exports != 'undefined') {
+  var test = require('./driver.js').test;
+  var testFail = require('./driver.js').testFail;
+}
+
+test(
+  "a &&= b",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 7,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 7,
+        "expression": {
+          "type": "AssignmentExpression",
+          "start": 0,
+          "end": 7,
+          "operator": "&&=",
+          "left": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 1,
+            "name": "a"
+          },
+          "right": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          }
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+test(
+  "a ||= b",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 7,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 7,
+        "expression": {
+          "type": "AssignmentExpression",
+          "start": 0,
+          "end": 7,
+          "operator": "||=",
+          "left": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 1,
+            "name": "a"
+          },
+          "right": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          }
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+test(
+  "a ??= b",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 7,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 7,
+        "expression": {
+          "type": "AssignmentExpression",
+          "start": 0,
+          "end": 7,
+          "operator": "??=",
+          "left": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 1,
+            "name": "a"
+          },
+          "right": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          }
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+test(
+  "a &&= b ||= c ??= d",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 19,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 19,
+        "expression": {
+          "type": "AssignmentExpression",
+          "start": 0,
+          "end": 19,
+          "operator": "&&=",
+          "left": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 1,
+            "name": "a"
+          },
+          "right": {
+            "type": "AssignmentExpression",
+            "start": 6,
+            "end": 19,
+            "operator": "||=",
+            "left": {
+              "type": "Identifier",
+              "start": 6,
+              "end": 7,
+              "name": "b"
+            },
+            "right": {
+              "type": "AssignmentExpression",
+              "start": 12,
+              "end": 19,
+              "operator": "??=",
+              "left": {
+                "type": "Identifier",
+                "start": 12,
+                "end": 13,
+                "name": "c"
+              },
+              "right": {
+                "type": "Identifier",
+                "start": 18,
+                "end": 19,
+                "name": "d"
+              }
+            }
+          }
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+testFail("a &&= b", "Unexpected token (1:4)", { ecmaVersion: 11 });
+testFail("a ||= b", "Unexpected token (1:4)", { ecmaVersion: 11 });
+testFail("a ??= b", "Unexpected token (1:4)", { ecmaVersion: 11 });
+
+testFail("({a} &&= b)", "Assigning to rvalue (1:1)", { ecmaVersion: 12 });
+testFail("({a} ||= b)", "Assigning to rvalue (1:1)", { ecmaVersion: 12 });
+testFail("({a} ??= b)", "Assigning to rvalue (1:1)", { ecmaVersion: 12 });
diff --git a/test/tests-nullish-coalescing.js b/test/tests-nullish-coalescing.js
new file mode 100644
index 000000000..6cd14a5d9
--- /dev/null
+++ b/test/tests-nullish-coalescing.js
@@ -0,0 +1,546 @@
+
+if (typeof exports != "undefined") {
+  var driver = require("./driver.js");
+  var test = driver.test, testFail = driver.testFail, testAssert = driver.testAssert, misMatch = driver.misMatch;
+  var acorn = require("../acorn");
+}
+
+test("a ?? b", {
+  "type": "Program",
+  "start": 0,
+  "end": 6,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 6,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 6,
+        "left": {
+          "type": "Identifier",
+          "start": 0,
+          "end": 1,
+          "name": "a"
+        },
+        "operator": "??",
+        "right": {
+          "type": "Identifier",
+          "start": 5,
+          "end": 6,
+          "name": "b"
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("a ?? b ?? c", {
+  "type": "Program",
+  "start": 0,
+  "end": 11,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 11,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 11,
+        "left": {
+          "type": "LogicalExpression",
+          "start": 0,
+          "end": 6,
+          "left": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 1,
+            "name": "a"
+          },
+          "operator": "??",
+          "right": {
+            "type": "Identifier",
+            "start": 5,
+            "end": 6,
+            "name": "b"
+          }
+        },
+        "operator": "??",
+        "right": {
+          "type": "Identifier",
+          "start": 10,
+          "end": 11,
+          "name": "c"
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+test("a | b ?? c | d", {
+  "type": "Program",
+  "start": 0,
+  "end": 14,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 14,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 14,
+        "left": {
+          "type": "BinaryExpression",
+          "start": 0,
+          "end": 5,
+          "left": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 1,
+            "name": "a"
+          },
+          "operator": "|",
+          "right": {
+            "type": "Identifier",
+            "start": 4,
+            "end": 5,
+            "name": "b"
+          }
+        },
+        "operator": "??",
+        "right": {
+          "type": "BinaryExpression",
+          "start": 9,
+          "end": 14,
+          "left": {
+            "type": "Identifier",
+            "start": 9,
+            "end": 10,
+            "name": "c"
+          },
+          "operator": "|",
+          "right": {
+            "type": "Identifier",
+            "start": 13,
+            "end": 14,
+            "name": "d"
+          }
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("a ?? b ? c : d", {
+  "type": "Program",
+  "start": 0,
+  "end": 14,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 14,
+      "expression": {
+        "type": "ConditionalExpression",
+        "start": 0,
+        "end": 14,
+        "test": {
+          "type": "LogicalExpression",
+          "start": 0,
+          "end": 6,
+          "left": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 1,
+            "name": "a"
+          },
+          "operator": "??",
+          "right": {
+            "type": "Identifier",
+            "start": 5,
+            "end": 6,
+            "name": "b"
+          }
+        },
+        "consequent": {
+          "type": "Identifier",
+          "start": 9,
+          "end": 10,
+          "name": "c"
+        },
+        "alternate": {
+          "type": "Identifier",
+          "start": 13,
+          "end": 14,
+          "name": "d"
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+test("(a || b) ?? c", {
+  "type": "Program",
+  "start": 0,
+  "end": 13,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 13,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 13,
+        "left": {
+          "type": "LogicalExpression",
+          "start": 1,
+          "end": 7,
+          "left": {
+            "type": "Identifier",
+            "start": 1,
+            "end": 2,
+            "name": "a"
+          },
+          "operator": "||",
+          "right": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          }
+        },
+        "operator": "??",
+        "right": {
+          "type": "Identifier",
+          "start": 12,
+          "end": 13,
+          "name": "c"
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("a || (b ?? c)", {
+  "type": "Program",
+  "start": 0,
+  "end": 13,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 13,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 13,
+        "left": {
+          "type": "Identifier",
+          "start": 0,
+          "end": 1,
+          "name": "a"
+        },
+        "operator": "||",
+        "right": {
+          "type": "LogicalExpression",
+          "start": 6,
+          "end": 12,
+          "left": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          },
+          "operator": "??",
+          "right": {
+            "type": "Identifier",
+            "start": 11,
+            "end": 12,
+            "name": "c"
+          }
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+test("(a && b) ?? c", {
+  "type": "Program",
+  "start": 0,
+  "end": 13,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 13,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 13,
+        "left": {
+          "type": "LogicalExpression",
+          "start": 1,
+          "end": 7,
+          "left": {
+            "type": "Identifier",
+            "start": 1,
+            "end": 2,
+            "name": "a"
+          },
+          "operator": "&&",
+          "right": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          }
+        },
+        "operator": "??",
+        "right": {
+          "type": "Identifier",
+          "start": 12,
+          "end": 13,
+          "name": "c"
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("a && (b ?? c)", {
+  "type": "Program",
+  "start": 0,
+  "end": 13,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 13,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 13,
+        "left": {
+          "type": "Identifier",
+          "start": 0,
+          "end": 1,
+          "name": "a"
+        },
+        "operator": "&&",
+        "right": {
+          "type": "LogicalExpression",
+          "start": 6,
+          "end": 12,
+          "left": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          },
+          "operator": "??",
+          "right": {
+            "type": "Identifier",
+            "start": 11,
+            "end": 12,
+            "name": "c"
+          }
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+test("(a ?? b) || c", {
+  "type": "Program",
+  "start": 0,
+  "end": 13,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 13,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 13,
+        "left": {
+          "type": "LogicalExpression",
+          "start": 1,
+          "end": 7,
+          "left": {
+            "type": "Identifier",
+            "start": 1,
+            "end": 2,
+            "name": "a"
+          },
+          "operator": "??",
+          "right": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          }
+        },
+        "operator": "||",
+        "right": {
+          "type": "Identifier",
+          "start": 12,
+          "end": 13,
+          "name": "c"
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("a ?? (b || c)", {
+  "type": "Program",
+  "start": 0,
+  "end": 13,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 13,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 13,
+        "left": {
+          "type": "Identifier",
+          "start": 0,
+          "end": 1,
+          "name": "a"
+        },
+        "operator": "??",
+        "right": {
+          "type": "LogicalExpression",
+          "start": 6,
+          "end": 12,
+          "left": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          },
+          "operator": "||",
+          "right": {
+            "type": "Identifier",
+            "start": 11,
+            "end": 12,
+            "name": "c"
+          }
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+test("(a ?? b) && c", {
+  "type": "Program",
+  "start": 0,
+  "end": 13,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 13,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 13,
+        "left": {
+          "type": "LogicalExpression",
+          "start": 1,
+          "end": 7,
+          "left": {
+            "type": "Identifier",
+            "start": 1,
+            "end": 2,
+            "name": "a"
+          },
+          "operator": "??",
+          "right": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          }
+        },
+        "operator": "&&",
+        "right": {
+          "type": "Identifier",
+          "start": 12,
+          "end": 13,
+          "name": "c"
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("a ?? (b && c)", {
+  "type": "Program",
+  "start": 0,
+  "end": 13,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 13,
+      "expression": {
+        "type": "LogicalExpression",
+        "start": 0,
+        "end": 13,
+        "left": {
+          "type": "Identifier",
+          "start": 0,
+          "end": 1,
+          "name": "a"
+        },
+        "operator": "??",
+        "right": {
+          "type": "LogicalExpression",
+          "start": 6,
+          "end": 12,
+          "left": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 7,
+            "name": "b"
+          },
+          "operator": "&&",
+          "right": {
+            "type": "Identifier",
+            "start": 11,
+            "end": 12,
+            "name": "c"
+          }
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+testFail("a ?? b", "Unexpected token (1:3)", { ecmaVersion: 10 })
+testFail("?? b", "Unexpected token (1:0)", { ecmaVersion: 11 })
+testFail("a ??", "Unexpected token (1:4)", { ecmaVersion: 11 })
+testFail("a || b ?? c", "Logical expressions and coalesce expressions cannot be mixed. Wrap either by parentheses (1:7)", { ecmaVersion: 11 })
+testFail("a && b ?? c", "Logical expressions and coalesce expressions cannot be mixed. Wrap either by parentheses (1:7)", { ecmaVersion: 11 })
+testFail("a ?? b || c", "Logical expressions and coalesce expressions cannot be mixed. Wrap either by parentheses (1:7)", { ecmaVersion: 11 })
+testFail("a ?? b && c", "Logical expressions and coalesce expressions cannot be mixed. Wrap either by parentheses (1:7)", { ecmaVersion: 11 })
+
+testFail("a+1 || b+1 ?? c", "Logical expressions and coalesce expressions cannot be mixed. Wrap either by parentheses (1:11)", { ecmaVersion: 11 })
+testFail("a+1 && b+1 ?? c", "Logical expressions and coalesce expressions cannot be mixed. Wrap either by parentheses (1:11)", { ecmaVersion: 11 })
+testFail("a+1 ?? b+1 || c", "Logical expressions and coalesce expressions cannot be mixed. Wrap either by parentheses (1:11)", { ecmaVersion: 11 })
+testFail("a+1 ?? b+1 && c", "Logical expressions and coalesce expressions cannot be mixed. Wrap either by parentheses (1:11)", { ecmaVersion: 11 })
diff --git a/test/tests-numeric-separators.js b/test/tests-numeric-separators.js
new file mode 100644
index 000000000..e28ef5055
--- /dev/null
+++ b/test/tests-numeric-separators.js
@@ -0,0 +1,199 @@
+// Tests for ECMAScript 2021 Numeric Separators
+
+if (typeof exports != 'undefined') {
+  var test = require('./driver.js').test;
+  var testFail = require('./driver.js').testFail;
+}
+
+function bigint(str) {
+  if (typeof BigInt !== "function") {
+    return null
+  }
+  return BigInt(str)
+}
+
+test(
+  "123_456",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 7,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 7,
+        "expression": {
+          "type": "Literal",
+          "start": 0,
+          "end": 7,
+          "value": 123456,
+          "raw": "123_456"
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+test(
+  "123_456.123_456e+123_456",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 24,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 24,
+        "expression": {
+          "type": "Literal",
+          "start": 0,
+          "end": 24,
+          "value": 123456.123456e+123456,
+          "raw": "123_456.123_456e+123_456"
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+test(
+  "0b1010_0001",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 11,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 11,
+        "expression": {
+          "type": "Literal",
+          "start": 0,
+          "end": 11,
+          "value": 0b10100001,
+          "raw": "0b1010_0001"
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+test(
+  "0xDEAD_BEAF",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 11,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 11,
+        "expression": {
+          "type": "Literal",
+          "start": 0,
+          "end": 11,
+          "value": 0xDEADBEAF,
+          "raw": "0xDEAD_BEAF"
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+test(
+  "0o755_666",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 9,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 9,
+        "expression": {
+          "type": "Literal",
+          "start": 0,
+          "end": 9,
+          "value": 0o755666,
+          "raw": "0o755_666"
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+test(
+  "123_456n",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 8,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 8,
+        "expression": {
+          "type": "Literal",
+          "start": 0,
+          "end": 8,
+          "value": bigint("123456"),
+          "raw": "123_456n",
+          "bigint": "123456"
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+test(
+  ".012_345",
+  {
+    "type": "Program",
+    "start": 0,
+    "end": 8,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 8,
+        "expression": {
+          "type": "Literal",
+          "start": 0,
+          "end": 8,
+          "value": 0.012345,
+          "raw": ".012_345"
+        }
+      }
+    ],
+    "sourceType": "script"
+  },
+  { ecmaVersion: 12 }
+);
+
+testFail("123_456", "Identifier directly after number (1:3)", { ecmaVersion: 11 });
+testFail("123__456", "Numeric separator must be exactly one underscore (1:4)", { ecmaVersion: 12 });
+testFail("0._123456", "Numeric separator is not allowed at the first of digits (1:2)", { ecmaVersion: 12 });
+testFail("123456_", "Numeric separator is not allowed at the last of digits (1:6)", { ecmaVersion: 12 });
+testFail("012_345", "Numeric separator is not allowed in legacy octal numeric literals (1:3)", { ecmaVersion: 12 });
+
+testFail("'\\x2_0'", "Bad character escape sequence (1:3)", { ecmaVersion: 12 });
+testFail("'\\u00_20'", "Bad character escape sequence (1:3)", { ecmaVersion: 12 });
+testFail("'\\u{2_0}'", "Bad character escape sequence (1:4)", { ecmaVersion: 12 });
diff --git a/test/tests-optional-chaining.js b/test/tests-optional-chaining.js
new file mode 100644
index 000000000..18cb1f204
--- /dev/null
+++ b/test/tests-optional-chaining.js
@@ -0,0 +1,1429 @@
+
+if (typeof exports != "undefined") {
+  var driver = require("./driver.js");
+  var test = driver.test, testFail = driver.testFail, testAssert = driver.testAssert, misMatch = driver.misMatch;
+  var acorn = require("../acorn");
+}
+
+// Simple
+test("obj?.foo", {
+  "type": "Program",
+  "start": 0,
+  "end": 8,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 8,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 8,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 8,
+          "object": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 3,
+            "name": "obj"
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 5,
+            "end": 8,
+            "name": "foo"
+          },
+          "computed": false,
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("obj?.[foo]", {
+  "type": "Program",
+  "start": 0,
+  "end": 10,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 10,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 10,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 10,
+          "object": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 3,
+            "name": "obj"
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 6,
+            "end": 9,
+            "name": "foo"
+          },
+          "computed": true,
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("obj?.()", {
+  "type": "Program",
+  "start": 0,
+  "end": 7,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 7,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 7,
+        "expression": {
+          "type": "CallExpression",
+          "start": 0,
+          "end": 7,
+          "callee": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 3,
+            "name": "obj"
+          },
+          "arguments": [],
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+// Simple with spacing
+test("obj ?. foo", {
+  "type": "Program",
+  "start": 0,
+  "end": 10,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 10,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 10,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 10,
+          "object": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 3,
+            "name": "obj"
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 7,
+            "end": 10,
+            "name": "foo"
+          },
+          "computed": false,
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("obj ?. [foo]", {
+  "type": "Program",
+  "start": 0,
+  "end": 12,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 12,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 12,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 12,
+          "object": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 3,
+            "name": "obj"
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 8,
+            "end": 11,
+            "name": "foo"
+          },
+          "computed": true,
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("obj ?. ()", {
+  "type": "Program",
+  "start": 0,
+  "end": 9,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 9,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 9,
+        "expression": {
+          "type": "CallExpression",
+          "start": 0,
+          "end": 9,
+          "callee": {
+            "type": "Identifier",
+            "start": 0,
+            "end": 3,
+            "name": "obj"
+          },
+          "arguments": [],
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+// Existing valid syntax
+test("obj?.0:.1", {
+  "type": "Program",
+  "start": 0,
+  "end": 9,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 9,
+      "expression": {
+        "type": "ConditionalExpression",
+        "start": 0,
+        "end": 9,
+        "test": {
+          "type": "Identifier",
+          "start": 0,
+          "end": 3,
+          "name": "obj"
+        },
+        "consequent": {
+          "type": "Literal",
+          "start": 4,
+          "end": 6,
+          "value": 0,
+          "raw": ".0"
+        },
+        "alternate": {
+          "type": "Literal",
+          "start": 7,
+          "end": 9,
+          "value": 0.1,
+          "raw": ".1"
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+// Chaining
+test("obj?.aaa?.bbb", {
+  "type": "Program",
+  "start": 0,
+  "end": 13,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 13,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 13,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 13,
+          "object": {
+            "type": "MemberExpression",
+            "start": 0,
+            "end": 8,
+            "object": {
+              "type": "Identifier",
+              "start": 0,
+              "end": 3,
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 5,
+              "end": 8,
+              "name": "aaa"
+            },
+            "computed": false,
+            "optional": true
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 10,
+            "end": 13,
+            "name": "bbb"
+          },
+          "computed": false,
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("obj?.aaa.bbb", {
+  "type": "Program",
+  "start": 0,
+  "end": 12,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 12,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 12,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 12,
+          "object": {
+            "type": "MemberExpression",
+            "start": 0,
+            "end": 8,
+            "object": {
+              "type": "Identifier",
+              "start": 0,
+              "end": 3,
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 5,
+              "end": 8,
+              "name": "aaa"
+            },
+            "computed": false,
+            "optional": true
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 9,
+            "end": 12,
+            "name": "bbb"
+          },
+          "computed": false,
+          "optional": false
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(obj?.aaa)?.bbb", {
+  "type": "Program",
+  "start": 0,
+  "end": 15,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 15,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 15,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 15,
+          "object": {
+            "type": "ChainExpression",
+            "start": 1,
+            "end": 9,
+            "expression": {
+              "type": "MemberExpression",
+              "start": 1,
+              "end": 9,
+              "object": {
+                "type": "Identifier",
+                "start": 1,
+                "end": 4,
+                "name": "obj"
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 6,
+                "end": 9,
+                "name": "aaa"
+              },
+              "computed": false,
+              "optional": true
+            }
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 12,
+            "end": 15,
+            "name": "bbb"
+          },
+          "computed": false,
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(obj?.aaa).bbb", {
+  "type": "Program",
+  "start": 0,
+  "end": 14,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 14,
+      "expression": {
+        "type": "MemberExpression",
+        "start": 0,
+        "end": 14,
+        "object": {
+          "type": "ChainExpression",
+          "start": 1,
+          "end": 9,
+          "expression": {
+            "type": "MemberExpression",
+            "start": 1,
+            "end": 9,
+            "object": {
+              "type": "Identifier",
+              "start": 1,
+              "end": 4,
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 6,
+              "end": 9,
+              "name": "aaa"
+            },
+            "computed": false,
+            "optional": true
+          }
+        },
+        "property": {
+          "type": "Identifier",
+          "start": 11,
+          "end": 14,
+          "name": "bbb"
+        },
+        "computed": false,
+        "optional": false
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(obj?.aaa.bbb).ccc", {
+  "type": "Program",
+  "start": 0,
+  "end": 18,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 18,
+      "expression": {
+        "type": "MemberExpression",
+        "start": 0,
+        "end": 18,
+        "object": {
+          "type": "ChainExpression",
+          "start": 1,
+          "end": 13,
+          "expression": {
+            "type": "MemberExpression",
+            "start": 1,
+            "end": 13,
+            "object": {
+              "type": "MemberExpression",
+              "start": 1,
+              "end": 9,
+              "object": {
+                "type": "Identifier",
+                "start": 1,
+                "end": 4,
+                "name": "obj"
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 6,
+                "end": 9,
+                "name": "aaa"
+              },
+              "computed": false,
+              "optional": true
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 10,
+              "end": 13,
+              "name": "bbb"
+            },
+            "computed": false,
+            "optional": false
+          }
+        },
+        "property": {
+          "type": "Identifier",
+          "start": 15,
+          "end": 18,
+          "name": "ccc"
+        },
+        "computed": false,
+        "optional": false
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+test("func?.()?.bbb", {
+  "type": "Program",
+  "start": 0,
+  "end": 13,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 13,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 13,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 13,
+          "object": {
+            "type": "CallExpression",
+            "start": 0,
+            "end": 8,
+            "callee": {
+              "type": "Identifier",
+              "start": 0,
+              "end": 4,
+              "name": "func"
+            },
+            "arguments": [],
+            "optional": true
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 10,
+            "end": 13,
+            "name": "bbb"
+          },
+          "computed": false,
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("func?.().bbb", {
+  "type": "Program",
+  "start": 0,
+  "end": 12,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 12,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 12,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 12,
+          "object": {
+            "type": "CallExpression",
+            "start": 0,
+            "end": 8,
+            "callee": {
+              "type": "Identifier",
+              "start": 0,
+              "end": 4,
+              "name": "func"
+            },
+            "arguments": [],
+            "optional": true
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 9,
+            "end": 12,
+            "name": "bbb"
+          },
+          "computed": false,
+          "optional": false
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(func?.())?.bbb", {
+  "type": "Program",
+  "start": 0,
+  "end": 15,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 15,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 15,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 15,
+          "object": {
+            "type": "ChainExpression",
+            "start": 1,
+            "end": 9,
+            "expression": {
+              "type": "CallExpression",
+              "start": 1,
+              "end": 9,
+              "callee": {
+                "type": "Identifier",
+                "start": 1,
+                "end": 5,
+                "name": "func"
+              },
+              "arguments": [],
+              "optional": true
+            }
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 12,
+            "end": 15,
+            "name": "bbb"
+          },
+          "computed": false,
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(func?.()).bbb", {
+  "type": "Program",
+  "start": 0,
+  "end": 14,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 14,
+      "expression": {
+        "type": "MemberExpression",
+        "start": 0,
+        "end": 14,
+        "object": {
+          "type": "ChainExpression",
+          "start": 1,
+          "end": 9,
+          "expression": {
+            "type": "CallExpression",
+            "start": 1,
+            "end": 9,
+            "callee": {
+              "type": "Identifier",
+              "start": 1,
+              "end": 5,
+              "name": "func"
+            },
+            "arguments": [],
+            "optional": true
+          }
+        },
+        "property": {
+          "type": "Identifier",
+          "start": 11,
+          "end": 14,
+          "name": "bbb"
+        },
+        "computed": false,
+        "optional": false
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+test("obj?.aaa?.()", {
+  "type": "Program",
+  "start": 0,
+  "end": 12,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 12,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 12,
+        "expression": {
+          "type": "CallExpression",
+          "start": 0,
+          "end": 12,
+          "callee": {
+            "type": "MemberExpression",
+            "start": 0,
+            "end": 8,
+            "object": {
+              "type": "Identifier",
+              "start": 0,
+              "end": 3,
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 5,
+              "end": 8,
+              "name": "aaa"
+            },
+            "computed": false,
+            "optional": true
+          },
+          "arguments": [],
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("obj?.aaa()", {
+  "type": "Program",
+  "start": 0,
+  "end": 10,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 10,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 10,
+        "expression": {
+          "type": "CallExpression",
+          "start": 0,
+          "end": 10,
+          "callee": {
+            "type": "MemberExpression",
+            "start": 0,
+            "end": 8,
+            "object": {
+              "type": "Identifier",
+              "start": 0,
+              "end": 3,
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 5,
+              "end": 8,
+              "name": "aaa"
+            },
+            "computed": false,
+            "optional": true
+          },
+          "arguments": [],
+          "optional": false
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(obj?.aaa)?.()", {
+  "type": "Program",
+  "start": 0,
+  "end": 14,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 14,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 14,
+        "expression": {
+          "type": "CallExpression",
+          "start": 0,
+          "end": 14,
+          "callee": {
+            "type": "ChainExpression",
+            "start": 1,
+            "end": 9,
+            "expression": {
+              "type": "MemberExpression",
+              "start": 1,
+              "end": 9,
+              "object": {
+                "type": "Identifier",
+                "start": 1,
+                "end": 4,
+                "name": "obj"
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 6,
+                "end": 9,
+                "name": "aaa"
+              },
+              "computed": false,
+              "optional": true
+            }
+          },
+          "arguments": [],
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(obj?.aaa)()", {
+  "type": "Program",
+  "start": 0,
+  "end": 12,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 12,
+      "expression": {
+        "type": "CallExpression",
+        "start": 0,
+        "end": 12,
+        "callee": {
+          "type": "ChainExpression",
+          "start": 1,
+          "end": 9,
+          "expression": {
+            "type": "MemberExpression",
+            "start": 1,
+            "end": 9,
+            "object": {
+              "type": "Identifier",
+              "start": 1,
+              "end": 4,
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 6,
+              "end": 9,
+              "name": "aaa"
+            },
+            "computed": false,
+            "optional": true
+          }
+        },
+        "arguments": [],
+        "optional": false
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+test("delete obj?.foo", {
+  "type": "Program",
+  "start": 0,
+  "end": 15,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 15,
+      "expression": {
+        "type": "UnaryExpression",
+        "start": 0,
+        "end": 15,
+        "operator": "delete",
+        "prefix": true,
+        "argument": {
+          "type": "ChainExpression",
+          "start": 7,
+          "end": 15,
+          "expression": {
+            "type": "MemberExpression",
+            "start": 7,
+            "end": 15,
+            "object": {
+              "type": "Identifier",
+              "start": 7,
+              "end": 10,
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 12,
+              "end": 15,
+              "name": "foo"
+            },
+            "computed": false,
+            "optional": true
+          }
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+// OK if paranthesized.
+test("new (obj?.foo)()", {
+  "type": "Program",
+  "start": 0,
+  "end": 16,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 16,
+      "expression": {
+        "type": "NewExpression",
+        "start": 0,
+        "end": 16,
+        "callee": {
+          "type": "ChainExpression",
+          "start": 5,
+          "end": 13,
+          "expression": {
+            "type": "MemberExpression",
+            "start": 5,
+            "end": 13,
+            "object": {
+              "type": "Identifier",
+              "start": 5,
+              "end": 8,
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 10,
+              "end": 13,
+              "name": "foo"
+            },
+            "computed": false,
+            "optional": true
+          }
+        },
+        "arguments": []
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(obj?.foo)`template`", {
+  "type": "Program",
+  "start": 0,
+  "end": 20,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 20,
+      "expression": {
+        "type": "TaggedTemplateExpression",
+        "start": 0,
+        "end": 20,
+        "tag": {
+          "type": "ChainExpression",
+          "start": 1,
+          "end": 9,
+          "expression": {
+            "type": "MemberExpression",
+            "start": 1,
+            "end": 9,
+            "object": {
+              "type": "Identifier",
+              "start": 1,
+              "end": 4,
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 6,
+              "end": 9,
+              "name": "foo"
+            },
+            "computed": false,
+            "optional": true
+          }
+        },
+        "quasi": {
+          "type": "TemplateLiteral",
+          "start": 10,
+          "end": 20,
+          "expressions": [],
+          "quasis": [
+            {
+              "type": "TemplateElement",
+              "start": 11,
+              "end": 19,
+              "value": {
+                "raw": "template",
+                "cooked": "template"
+              },
+              "tail": true
+            }
+          ]
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(obj?.foo).bar = 0", {
+  "type": "Program",
+  "start": 0,
+  "end": 18,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 18,
+      "expression": {
+        "type": "AssignmentExpression",
+        "start": 0,
+        "end": 18,
+        "operator": "=",
+        "left": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 14,
+          "object": {
+            "type": "ChainExpression",
+            "start": 1,
+            "end": 9,
+            "expression": {
+              "type": "MemberExpression",
+              "start": 1,
+              "end": 9,
+              "object": {
+                "type": "Identifier",
+                "start": 1,
+                "end": 4,
+                "name": "obj"
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 6,
+                "end": 9,
+                "name": "foo"
+              },
+              "computed": false,
+              "optional": true
+            }
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 11,
+            "end": 14,
+            "name": "bar"
+          },
+          "computed": false,
+          "optional": false
+        },
+        "right": {
+          "type": "Literal",
+          "start": 17,
+          "end": 18,
+          "value": 0,
+          "raw": "0"
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(obj?.foo).bar++", {
+  "type": "Program",
+  "start": 0,
+  "end": 16,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 16,
+      "expression": {
+        "type": "UpdateExpression",
+        "start": 0,
+        "end": 16,
+        "operator": "++",
+        "prefix": false,
+        "argument": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 14,
+          "object": {
+            "type": "ChainExpression",
+            "start": 1,
+            "end": 9,
+            "expression": {
+              "type": "MemberExpression",
+              "start": 1,
+              "end": 9,
+              "object": {
+                "type": "Identifier",
+                "start": 1,
+                "end": 4,
+                "name": "obj"
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 6,
+                "end": 9,
+                "name": "foo"
+              },
+              "computed": false,
+              "optional": true
+            }
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 11,
+            "end": 14,
+            "name": "bar"
+          },
+          "computed": false,
+          "optional": false
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("for ((obj?.foo).bar of []);", {
+  "type": "Program",
+  "start": 0,
+  "end": 27,
+  "body": [
+    {
+      "type": "ForOfStatement",
+      "start": 0,
+      "end": 27,
+      "await": false,
+      "left": {
+        "type": "MemberExpression",
+        "start": 5,
+        "end": 19,
+        "object": {
+          "type": "ChainExpression",
+          "start": 6,
+          "end": 14,
+          "expression": {
+            "type": "MemberExpression",
+            "start": 6,
+            "end": 14,
+            "object": {
+              "type": "Identifier",
+              "start": 6,
+              "end": 9,
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 11,
+              "end": 14,
+              "name": "foo"
+            },
+            "computed": false,
+            "optional": true
+          }
+        },
+        "property": {
+          "type": "Identifier",
+          "start": 16,
+          "end": 19,
+          "name": "bar"
+        },
+        "computed": false,
+        "optional": false
+      },
+      "right": {
+        "type": "ArrayExpression",
+        "start": 23,
+        "end": 25,
+        "elements": []
+      },
+      "body": {
+        "type": "EmptyStatement",
+        "start": 26,
+        "end": 27
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+// With ParenthesizedExpression
+test("(obj?.aaa).bbb", {
+  "type": "Program",
+  "start": 0,
+  "end": 14,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 14,
+      "expression": {
+        "type": "MemberExpression",
+        "start": 0,
+        "end": 14,
+        "object": {
+          "type": "ParenthesizedExpression",
+          "start": 0,
+          "end": 10,
+          "expression": {
+            "type": "ChainExpression",
+            "start": 1,
+            "end": 9,
+            "expression": {
+              "type": "MemberExpression",
+              "start": 1,
+              "end": 9,
+              "object": {
+                "type": "Identifier",
+                "start": 1,
+                "end": 4,
+                "name": "obj"
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 6,
+                "end": 9,
+                "name": "aaa"
+              },
+              "computed": false,
+              "optional": true
+            }
+          }
+        },
+        "property": {
+          "type": "Identifier",
+          "start": 11,
+          "end": 14,
+          "name": "bbb"
+        },
+        "computed": false,
+        "optional": false
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11, preserveParens: true })
+
+// No ChainExpression if `callee|object` doesn't contain `?.` even if it's parenthesized.
+test("(obj.foo.bar)?.buz", {
+  "type": "Program",
+  "start": 0,
+  "end": 18,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 18,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 18,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 18,
+          "object": {
+            "type": "MemberExpression",
+            "start": 1,
+            "end": 12,
+            "object": {
+              "type": "MemberExpression",
+              "start": 1,
+              "end": 8,
+              "object": {
+                "type": "Identifier",
+                "start": 1,
+                "end": 4,
+                "name": "obj"
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 5,
+                "end": 8,
+                "name": "foo"
+              },
+              "computed": false,
+              "optional": false
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 9,
+              "end": 12,
+              "name": "bar"
+            },
+            "computed": false,
+            "optional": false
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 15,
+            "end": 18,
+            "name": "buz"
+          },
+          "computed": false,
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+test("(obj.foo())?.buz", {
+  "type": "Program",
+  "start": 0,
+  "end": 16,
+  "body": [
+    {
+      "type": "ExpressionStatement",
+      "start": 0,
+      "end": 16,
+      "expression": {
+        "type": "ChainExpression",
+        "start": 0,
+        "end": 16,
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 16,
+          "object": {
+            "type": "CallExpression",
+            "start": 1,
+            "end": 10,
+            "callee": {
+              "type": "MemberExpression",
+              "start": 1,
+              "end": 8,
+              "object": {
+                "type": "Identifier",
+                "start": 1,
+                "end": 4,
+                "name": "obj"
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 5,
+                "end": 8,
+                "name": "foo"
+              },
+              "computed": false,
+              "optional": false
+            },
+            "arguments": [],
+            "optional": false
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 13,
+            "end": 16,
+            "name": "buz"
+          },
+          "computed": false,
+          "optional": true
+        }
+      }
+    }
+  ],
+  "sourceType": "script"
+}, { ecmaVersion: 11 })
+
+// With an old ecmaVersion.
+testFail("obj?.foo", "Unexpected token (1:4)", { ecmaVersion: 10 })
+testFail("obj?.[foo]", "Unexpected token (1:4)", { ecmaVersion: 10 })
+testFail("obj?.()", "Unexpected token (1:4)", { ecmaVersion: 10 })
+
+// Syntax errors.
+testFail("obj?.0", "Unexpected token (1:6)", { ecmaVersion: 11 })
+testFail("async?.() => {}", "Unexpected token (1:10)", { ecmaVersion: 11 })
+testFail("new obj?.()", "Optional chaining cannot appear in the callee of new expressions (1:7)", { ecmaVersion: 11 })
+testFail("new obj?.foo()", "Optional chaining cannot appear in the callee of new expressions (1:7)", { ecmaVersion: 11 })
+testFail("obj?.foo\n`template`", "Optional chaining cannot appear in the tag of tagged template expressions (2:0)", { ecmaVersion: 11 })
+testFail("obj?.foo = 0", "Optional chaining cannot appear in left-hand side (1:0)", { ecmaVersion: 11 })
+testFail("obj?.foo.bar = 0", "Optional chaining cannot appear in left-hand side (1:0)", { ecmaVersion: 11 })
+testFail("obj?.().foo = 0", "Optional chaining cannot appear in left-hand side (1:0)", { ecmaVersion: 11 })
+testFail("obj?.foo++", "Optional chaining cannot appear in left-hand side (1:0)", { ecmaVersion: 11 })
+testFail("obj?.foo--", "Optional chaining cannot appear in left-hand side (1:0)", { ecmaVersion: 11 })
+testFail("++obj?.foo", "Optional chaining cannot appear in left-hand side (1:2)", { ecmaVersion: 11 })
+testFail("--obj?.foo", "Optional chaining cannot appear in left-hand side (1:2)", { ecmaVersion: 11 })
+testFail("obj?.foo.bar++", "Optional chaining cannot appear in left-hand side (1:0)", { ecmaVersion: 11 })
+testFail("for (obj?.foo in {});", "Optional chaining cannot appear in left-hand side (1:5)", { ecmaVersion: 11 })
+testFail("for (obj?.foo.bar in {});", "Optional chaining cannot appear in left-hand side (1:5)", { ecmaVersion: 11 })
+testFail("for (obj?.foo of []);", "Optional chaining cannot appear in left-hand side (1:5)", { ecmaVersion: 11 })
+testFail("for (obj?.foo.bar of []);", "Optional chaining cannot appear in left-hand side (1:5)", { ecmaVersion: 11 })
diff --git a/test/tests-regexp-2020.js b/test/tests-regexp-2020.js
new file mode 100644
index 000000000..7caff8f2a
--- /dev/null
+++ b/test/tests-regexp-2020.js
@@ -0,0 +1,21 @@
+if (typeof exports != "undefined") {
+  var test = require("./driver.js").test
+  var testFail = require("./driver.js").testFail
+}
+
+// https://github.com/tc39/ecma262/pull/1869
+testFail("/(?<\\ud835\\udc9c>.)/", "Invalid regular expression: /(?<\\ud835\\udc9c>.)/: Invalid capture group name (1:1)", { ecmaVersion: 2019 })
+test("/(?<\\ud835\\udc9c>.)/", {}, { ecmaVersion: 2020 })
+test("/(?<\\ud835\\udc9c>.)/u", {}, { ecmaVersion: 2019 })
+test("/(?<\\ud835\\udc9c>.)/u", {}, { ecmaVersion: 2020 })
+
+testFail("/(?<\\u{1d49c}>.)/", "Invalid regular expression: /(?<\\u{1d49c}>.)/: Invalid capture group name (1:1)", { ecmaVersion: 2019 })
+test("/(?<\\u{1d49c}>.)/", {}, { ecmaVersion: 2020 })
+test("/(?<\\u{1d49c}>.)/u", {}, { ecmaVersion: 2019 })
+test("/(?<\\u{1d49c}>.)/u", {}, { ecmaVersion: 2020 })
+
+testFail("/(?<𝒜>.)/", "Invalid regular expression: /(?<𝒜>.)/: Invalid capture group name (1:1)", { ecmaVersion: 2019 })
+test("/(?<𝒜>.)/", {}, { ecmaVersion: 2020 })
+test("/(?<𝒜>.)/u", {}, { ecmaVersion: 2019 })
+test("/(?<𝒜>.)/u", {}, { ecmaVersion: 2020 })
+
diff --git a/test/tests-regexp.js b/test/tests-regexp.js
index 6c4719486..804e00a59 100644
--- a/test/tests-regexp.js
+++ b/test/tests-regexp.js
@@ -1049,6 +1049,7 @@ test("/[\\d][\\12-\\14]{1,}[^\\d]/", {}, { ecmaVersion: 2015 })
 testFail("/[\\d][\\12-\\14]{1,}[^\\d]/u", "Invalid regular expression flag (1:1)", { ecmaVersion: 5 })
 testFail("/[\\d][\\12-\\14]{1,}[^\\d]/u", "Invalid regular expression: /[\\d][\\12-\\14]{1,}[^\\d]/: Invalid class escape (1:1)", { ecmaVersion: 2015 })
 test("/([a ]\\b)*\\b/", {}, { ecmaVersion: 5 })
+test("/[x-*]/u".replace("*", String.fromCharCode(0xd800)), {}, {ecmaVersion: 6})
 
 /*
 // This is test case generator.
diff --git a/test/tests.js b/test/tests.js
index 35fe29ca5..0a0031484 100644
--- a/test/tests.js
+++ b/test/tests.js
@@ -29428,7 +29428,7 @@ test("(\\u0061sync ())", {
 }, {ecmaVersion: 8})
 testFail("({ \\u0061sync x() { await x } })", "Unexpected token (1:14)", {ecmaVersion: 8})
 testFail("for (x \\u006ff y) {}", "Unexpected token (1:7)", {ecmaVersion: 6})
-testFail("function x () { new.ta\\u0072get }", "The only valid meta property for new is new.target (1:20)", {ecmaVersion: 6})
+testFail("function x () { new.ta\\u0072get }", "'new.target' must not contain escaped characters (1:16)", {ecmaVersion: 6})
 testFail("class X { st\\u0061tic y() {} }", "Unexpected token (1:22)", {ecmaVersion: 6})
 
 testFail("(x=1)=2", "Parenthesized pattern (1:0)")
@@ -29464,3 +29464,16 @@ test("/**/ --> comment\n", {})
 test("x.class++", {})
 
 testFail("½", "Unexpected character '½' (1:0)")
+
+// Ignore use-strict strings that aren't a stand-along expression
+test("'use strict'.foo; 05", {}, {ecmaVersion: 6})
+test("'use strict'\n.foo; 05", {}, {ecmaVersion: 6})
+test("\"use strict\"(foo); 05", {}, {ecmaVersion: 6})
+test("'use strict'`foo`; 05", {}, {ecmaVersion: 6})
+test("'use strict'\n+ 10; 05", {}, {ecmaVersion: 6})
+test("'use strict'\n!=10; 05", {}, {ecmaVersion: 6})
+
+// Don't ignore those that are, even with semicolon insertion
+testFail("\"use strict\"\nfoo\n05", "Invalid number (3:0)", {ecmaVersion: 6})
+testFail("\"use strict\"\n;(foo)\n05", "Invalid number (3:0)", {ecmaVersion: 6})
+testFail("'use strict'\n!blah; 05", "Invalid number (2:7)", {ecmaVersion: 6})