Make jsesc isScriptContext optional

+ Adds option isScriptContext to constant folding plugin
+ Fix #440, fix #413
+ Related #384, #382

Author: boopathi

packages/babel-plugin-minify-constant-folding/__tests__/constant-folding-test.js

@@ -3,9 +3,9 @@ jest.autoMockOff();
 const babel = require("babel-core");
 const unpad = require("../../../utils/unpad");
 
-function transform(code) {
+function transform(code, opts = {}) {
   return babel.transform(code, {
-    plugins: [require("../src/index")]
+    plugins: [[require("../src/index"), opts]]
   }).code;
 }
 
@@ -83,7 +83,7 @@ describe("constant-folding-plugin", () => {
       "<\\\\/script";
     `
     );
-    expect(transform(source)).toBe(expected);
+    expect(transform(source, { isScriptContext: true })).toBe(expected);
   });
 
   it("should handle style escape", () => {
@@ -98,7 +98,7 @@ describe("constant-folding-plugin", () => {
       "<\\\\/style";
     `
     );
-    expect(transform(source)).toBe(expected);
+    expect(transform(source, { isScriptContext: true })).toBe(expected);
   });
 
   it("should handle html comment escape", () => {
@@ -113,6 +113,20 @@ describe("constant-folding-plugin", () => {
       "\\\\x3C!--";
     `
     );
+    expect(transform(source, { isScriptContext: true })).toBe(expected);
+  });
+
+  it("should fix #440", () => {
+    const source = unpad(
+      `
+      var x = "'cool'" + "test";
+      `
+    );
+    const expected = unpad(
+      `
+      var x = "'cool'test";
+      `
+    );
     expect(transform(source)).toBe(expected);
   });
 });

packages/babel-plugin-minify-constant-folding/src/index.js

@@ -55,7 +55,7 @@ module.exports = ({ types: t, traverse }) => {
       },
 
       // TODO: look into evaluating binding too (could result in more code, but gzip?)
-      Expression(path) {
+      Expression(path, { opts: { isScriptContext = false } }) {
         const { node } = path;
 
         if (node[seen]) {
@@ -122,10 +122,8 @@ module.exports = ({ types: t, traverse }) => {
           }
 
           // https://github.com/babel/babili/issues/382
-          if (typeof res.value === "string") {
-            res.value = jsesc(res.value, {
-              isScriptContext: true
-            });
+          if (typeof res.value === "string" && isScriptContext) {
+            res.value = jsesc(res.value, { isScriptContext });
           }
 
           const node = t.valueToNode(res.value);