Optimizer: include char unescape to index

Author: DmitrySoshnikov

src/optimizer/__tests__/optimizer-integration-test.js

@@ -25,6 +25,14 @@ describe('optimizer-integration-test', () => {
       .toBe(optimized.toString());
   });
 
+  it('preserve escape', () => {
+    const original = /^[\^\*\$\(\)]\^\*\$\(\)$/;
+    const optimized = /^[^*$()]\^\*\$\(\)$/;
+
+    expect(optimizer.optimize(original).toString())
+      .toBe(optimized.toString());
+  });
+
   it('whitespace', () => {
     const original = /[ \n\r\t\f]+/;
     const optimized = /\s+/;

src/optimizer/transforms/__tests__/char-escape-unescape-transform-test.js

@@ -17,11 +17,18 @@ describe('\e -> e', () => {
     expect(re.toString()).toBe(/e\*/.toString());
   });
 
+  it('preserve escape', () => {
+    const re = transform(/\*\^\$\(\)\[/, [
+      charUnescape,
+    ]);
+    expect(re.toString()).toBe(/\*\^\$\(\)\[/.toString());
+  });
+
   it('char class', () => {
-    const re = transform(/[\e\*\(\]\ ]\(\n/, [
+    const re = transform(/[\e\*\(\]\ \^\$]\(\n/, [
       charUnescape,
     ]);
-    expect(re.toString()).toBe(/[e*(\] ]\(\n/.toString());
+    expect(re.toString()).toBe(/[e*(\] ^$]\(\n/.toString());
   });
 
 });

src/optimizer/transforms/char-escape-unescape-transform.js

@@ -39,5 +39,5 @@ function shouldUnescape(path) {
 }
 
 function preservesEscape(value) {
-  return /[*\[()+?]/.test(value);
+  return /[*\[()+?^$]/.test(value);
 }

src/optimizer/transforms/index.js

@@ -20,4 +20,7 @@ module.exports = [
 
   // aa* -> a+
   require('./char-star-to-plus-transform'),
+
+  // \e -> e
+  require('./char-escape-unescape-transform'),
 ];