fix(1685): refine export assignment diagnostics to match strada

internal/checker/checker.go

@@ -5417,7 +5417,7 @@ func (c *Checker) checkExternalModuleExports(node *ast.Node) {
 		exportEqualsSymbol := moduleSymbol.Exports[ast.InternalSymbolNameExportEquals]
 		if exportEqualsSymbol != nil && c.hasExportedMembers(moduleSymbol) {
 			declaration := core.OrElse(c.getDeclarationOfAliasSymbol(exportEqualsSymbol), exportEqualsSymbol.ValueDeclaration)
-			if declaration != nil && !isTopLevelInExternalModuleAugmentation(declaration) {
+			if declaration != nil && !isTopLevelInExternalModuleAugmentation(declaration) && !ast.IsInJSFile(declaration) {
 				c.error(declaration, diagnostics.An_export_assignment_cannot_be_used_in_a_module_with_other_exported_elements)
 			}
 		}

internal/transformers/declarations/transform.go

@@ -1498,6 +1498,9 @@ func (tx *DeclarationTransformer) ensureModifierFlags(node *ast.Node) ast.Modifi
 		mask ^= ast.ModifierFlagsAmbient
 		additions = ast.ModifierFlagsNone
 	}
+	if tx.shouldSuppressExport(node) {
+		mask ^= ast.ModifierFlagsExport
+	}
 	return maskModifierFlags(tx.host, node, mask, additions)
 }
 
@@ -1796,3 +1799,22 @@ func (tx *DeclarationTransformer) transformJSDocOptionalType(input *ast.JSDocOpt
 	tx.EmitContext().SetOriginal(replacement, input.AsNode())
 	return replacement
 }
+
+func (tx *DeclarationTransformer) shouldSuppressExport(node *ast.Node) bool {
+	if node.Kind == ast.KindJSTypeAliasDeclaration && ast.IsSourceFile(node.Parent) && ast.IsExternalOrCommonJSModule(node.Parent.AsSourceFile()) {
+		sourceFile := node.Parent.AsSourceFile()
+		exports := []*ast.Node{
+			sourceFile.CommonJSModuleIndicator,
+			sourceFile.ExternalModuleIndicator,
+		}
+		for _, export := range exports {
+			if export == nil {
+				continue
+			}
+			if ast.IsAnyExportAssignment(export) && export.AsExportAssignment().IsExportEquals {
+				return true
+			}
+		}
+	}
+	return false
+}

testdata/baselines/reference/submodule/compiler/jsDeclarationEmitExportAssignedFunctionWithExtraTypedefsMembers.errors.txt

@@ -1,8 +1,7 @@
-index.js(9,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 index.js(9,34): error TS7006: Parameter 'options' implicitly has an 'any' type.
 
 
-==== index.js (2 errors) ====
+==== index.js (1 errors) ====
     /**
      * @typedef Options
      * @property {string} opt
@@ -12,8 +11,6 @@ index.js(9,34): error TS7006: Parameter 'options' implicitly has an 'any' type.
      * @param {Options} options
      */
     module.exports = function loader(options) {}
-    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
                                      ~~~~~~~
 !!! error TS7006: Parameter 'options' implicitly has an 'any' type.
 

testdata/baselines/reference/submodule/compiler/jsDeclarationEmitExportAssignedFunctionWithExtraTypedefsMembers.js

@@ -34,7 +34,7 @@ module.exports = function loader(options) { };
 
 
 //// [index.d.ts]
-export type Options = {
+type Options = {
     opt: string;
 };
 declare const _default: (options: any) => void;

testdata/baselines/reference/submodule/compiler/jsDeclarationEmitExportAssignedFunctionWithExtraTypedefsMembers.js.diff

@@ -25,8 +25,7 @@
 -}
 -declare function _exports(options: Options): void;
 -export = _exports;
--type Options = {
-+export type Options = {
+ type Options = {
      opt: string;
  };
 +declare const _default: (options: any) => void;

testdata/baselines/reference/submodule/compiler/jsExportAssignmentNonMutableLocation.errors.txt

@@ -1,18 +1,13 @@
-file.js(4,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 file.js(8,9): error TS2339: Property 'customSymbol2' does not exist on type 'typeof import("file")'.
 
 
-==== file.js (2 errors) ====
+==== file.js (1 errors) ====
     const customSymbol = Symbol("custom");
 
     // This is a common pattern in Node’s built-in modules:
     module.exports = {
-    ~~~~~~~~~~~~~~~~~~
         customSymbol,
-    ~~~~~~~~~~~~~~~~~
     };
-    ~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
 
     exports.customSymbol2 = Symbol("custom");
             ~~~~~~~~~~~~~

testdata/baselines/reference/submodule/compiler/jsExportMemberMergedWithModuleAugmentation3.errors.txt

@@ -1,14 +1,11 @@
 /x.js(1,16): error TS2339: Property 'x' does not exist on type 'typeof import("/y")'.
-/x.js(2,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 
 
-==== /x.js (2 errors) ====
+==== /x.js (1 errors) ====
     module.exports.x = 1;
                    ~
 !!! error TS2339: Property 'x' does not exist on type 'typeof import("/y")'.
     module.exports = require("./y.js");
-    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
 
 ==== /y.d.ts (0 errors) ====
     export declare type x = 1;

testdata/baselines/reference/submodule/compiler/pushTypeGetTypeOfAlias.errors.txt

@@ -1,12 +1,9 @@
-bar.js(1,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 bar.js(2,9): error TS2339: Property 'blah' does not exist on type 'typeof import("bar")'.
 bar.js(2,24): error TS2339: Property 'someProp' does not exist on type 'typeof import("bar")'.
 
 
-==== bar.js (3 errors) ====
+==== bar.js (2 errors) ====
     module.exports = function () {};
-    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
     exports.blah = exports.someProp;
             ~~~~
 !!! error TS2339: Property 'blah' does not exist on type 'typeof import("bar")'.

testdata/baselines/reference/submodule/conformance/callbackCrossModule.errors.txt

@@ -1,15 +1,12 @@
-mod1.js(5,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 use.js(1,30): error TS2694: Namespace 'C' has no exported member 'Con'.
 
 
-==== mod1.js (1 errors) ====
+==== mod1.js (0 errors) ====
     /** @callback Con - some kind of continuation
      * @param {object | undefined} error
      * @return {any} I don't even know what this should return
      */
     module.exports = C
-    ~~~~~~~~~~~~~~~~~~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
     function C() {
         this.p = 1
     }

testdata/baselines/reference/submodule/conformance/commonJSAliasedExport.errors.txt

@@ -1,5 +1,4 @@
 bug43713.js(1,9): error TS2305: Module '"./commonJSAliasedExport"' has no exported member 'funky'.
-commonJSAliasedExport.js(6,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 commonJSAliasedExport.js(7,16): error TS2339: Property 'funky' does not exist on type '(ast: any) => any'.
 
 
@@ -12,15 +11,13 @@ commonJSAliasedExport.js(7,16): error TS2339: Property 'funky' does not exist on
     var diddy = funky(1)
 
 
-==== commonJSAliasedExport.js (2 errors) ====
+==== commonJSAliasedExport.js (1 errors) ====
     const donkey = (ast) =>  ast;
 
     function funky(declaration) {
         return false;
     }
     module.exports = donkey;
-    ~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
     module.exports.funky = funky;
                    ~~~~~
 !!! error TS2339: Property 'funky' does not exist on type '(ast: any) => any'.

testdata/baselines/reference/submodule/conformance/conflictingCommonJSES2015Exports.errors.txt

@@ -1,12 +1,9 @@
-bug24934.js(2,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 use.js(1,21): error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'esModuleInterop' flag and referencing its default export.
 
 
-==== bug24934.js (1 errors) ====
+==== bug24934.js (0 errors) ====
     export function abc(a, b, c) { return 5; }
     module.exports = { abc };
-    ~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
 ==== use.js (1 errors) ====
     import { abc } from './bug24934';
                         ~~~~~~~~~~~~

testdata/baselines/reference/submodule/conformance/jsDeclarationsClassExtendsVisibility.errors.txt

@@ -1,17 +1,14 @@
-cls.js(7,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 cls.js(8,16): error TS2339: Property 'Strings' does not exist on type 'typeof Foo'.
 
 
-==== cls.js (2 errors) ====
+==== cls.js (1 errors) ====
     const Bar = require("./bar");
     const Strings = {
         a: "A",
         b: "B"
     };
     class Foo extends Bar {}
     module.exports = Foo;
-    ~~~~~~~~~~~~~~~~~~~~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
     module.exports.Strings = Strings;
                    ~~~~~~~
 !!! error TS2339: Property 'Strings' does not exist on type 'typeof Foo'.

testdata/baselines/reference/submodule/conformance/jsDeclarationsClassStatic.errors.txt

@@ -1,8 +1,7 @@
-source.js(15,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 source.js(16,16): error TS2339: Property 'Strings' does not exist on type 'typeof Handler'.
 
 
-==== source.js (2 errors) ====
+==== source.js (1 errors) ====
     class Handler {
     	static get OPTIONS() {
     		return 1;
@@ -18,8 +17,6 @@ source.js(16,16): error TS2339: Property 'Strings' does not exist on type 'typeo
     }
 
     module.exports = Handler;
-    ~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
     module.exports.Strings = Strings
                    ~~~~~~~
 !!! error TS2339: Property 'Strings' does not exist on type 'typeof Handler'.

testdata/baselines/reference/submodule/conformance/jsDeclarationsCrossfileMerge.errors.txt

@@ -1,13 +1,10 @@
-index.js(3,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 index.js(4,16): error TS2339: Property 'memberName' does not exist on type '() => void'.
 
 
-==== index.js (2 errors) ====
+==== index.js (1 errors) ====
     const m = require("./exporter");
 
     module.exports = m.default;
-    ~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
     module.exports.memberName = "thing";
                    ~~~~~~~~~~
 !!! error TS2339: Property 'memberName' does not exist on type '() => void'.

testdata/baselines/reference/submodule/conformance/jsDeclarationsExportAssignedClassExpressionAnonymousWithSub.errors.txt

@@ -1,25 +1,15 @@
-index.js(1,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
 index.js(9,16): error TS2339: Property 'Sub' does not exist on type 'typeof (Anonymous class)'.
 
 
-==== index.js (2 errors) ====
+==== index.js (1 errors) ====
     module.exports = class {
-    ~~~~~~~~~~~~~~~~~~~~~~~~
         /**
-    ~~~~~~~
          * @param {number} p
-    ~~~~~~~~~~~~~~~~~~~~~~~~
          */
-    ~~~~~~~
         constructor(p) {
-    ~~~~~~~~~~~~~~~~~~~~
             this.t = 12 + p;
-    ~~~~~~~~~~~~~~~~~~~~~~~~
         }
-    ~~~~~
     }
-    ~
-!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
     module.exports.Sub = class {
                    ~~~
 !!! error TS2339: Property 'Sub' does not exist on type 'typeof (Anonymous class)'.