Merge pull request #1382 from kondi/jscript

add optional jscript transformer for basic IE8 compatibility (fixes #1369)

src/babel/transformation/transformers/index.js

@@ -115,5 +115,6 @@ export default {
   "utility.inlineExpressions":             require("./utility/inline-expressions"),
   "utility.deadCodeElimination":           require("./utility/dead-code-elimination"),
 
+  jscript:                                 require("./other/jscript"),
   flow:                                    require("./other/flow")
 };

src/babel/transformation/transformers/other/jscript.js

@@ -0,0 +1,27 @@
+import * as t from "../../../types";
+
+export var metadata = {
+  optional: true
+};
+
+export function VariableDeclarator(node, print) {
+  var varName = node.id.name;
+  if (node.init) {
+    if (t.isFunctionExpression(node.init)) {
+      if (node.init.id) {
+        var fnName = node.init.id.name;
+        if (varName === fnName) {
+          node.init._ignoreUserWhitespace = true;
+          var closureBody = [
+            t.toStatement(node.init),
+            t.returnStatement(node.init.id)
+          ];
+          var init = t.callExpression(
+            t.functionExpression(null, [], t.blockStatement(closureBody)), []
+          );
+          return t.variableDeclarator(node.id, init);
+        }
+      }
+    }
+  }
+}

test/core/fixtures/transformation/jscript/options.json

@@ -0,0 +1,3 @@
+{
+  "optional": ["jscript"]
+}

test/core/fixtures/transformation/jscript/simple-class/actual.js

@@ -0,0 +1,2 @@
+class Test {
+}

test/core/fixtures/transformation/jscript/simple-class/expected.js

@@ -0,0 +1,9 @@
+"use strict";
+
+var Test = (function () {
+  function Test() {
+    babelHelpers.classCallCheck(this, Test);
+  }
+
+  return Test;
+})();

test/core/fixtures/transformation/jscript/simple-class/options.json

@@ -0,0 +1,3 @@
+{
+  "externalHelpers": true
+}

test/core/fixtures/transformation/jscript/var-named-function-expression/actual.js

@@ -0,0 +1,7 @@
+var IdenticalName = function IdenticalName(x) {
+  return x;
+};
+
+var DifferentNameA = function DifferentNameB(x) {
+  return x;
+};

test/core/fixtures/transformation/jscript/var-named-function-expression/expected.js

@@ -0,0 +1,13 @@
+"use strict";
+
+var IdenticalName = (function () {
+  function IdenticalName(x) {
+    return x;
+  }
+
+  return IdenticalName;
+})();
+
+var DifferentNameA = function DifferentNameB(x) {
+  return x;
+};