move jscript transformer to the builtin-trailing group and perform transform on exit - closes #1652, fixes #1651

src/babel/transformation/transformers/index.js

@@ -51,7 +51,6 @@ export default {
   "es6.spec.symbols":                      require("./es6/spec.symbols"),
   "es7.functionBind":                      require("./es7/function-bind"),
   "spec.undefinedToVoid":                  require("./spec/undefined-to-void"),
-  jscript:                                 require("./other/jscript"),
   flow:                                    require("./other/flow"),
 
   //- builtin-advanced
@@ -83,4 +82,5 @@ export default {
   "minification.memberExpressionLiterals": require("./minification/member-expression-literals"),
   "minification.propertyLiterals":         require("./minification/property-literals"),
   _blockHoist:                             require("./internal/block-hoist"),
+  jscript:                                 require("./other/jscript"),
 };

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

@@ -1,18 +1,21 @@
 import * as t from "../../../types";
 
 export var metadata = {
+  group: "builtin-trailing",
   optional: true
 };
 
-export function FunctionExpression(node, print) {
-  if (!node.id) return;
-  node._ignoreUserWhitespace = true;
+export var FunctionExpression = {
+  exit(node, print) {
+    if (!node.id) return;
+    node._ignoreUserWhitespace = true;
 
-  return t.callExpression(
-    t.functionExpression(null, [], t.blockStatement([
-      t.toStatement(node),
-      t.returnStatement(node.id)
-    ])),
-    []
-  );
-}
+    return t.callExpression(
+      t.functionExpression(null, [], t.blockStatement([
+        t.toStatement(node),
+        t.returnStatement(node.id)
+      ])),
+      []
+    );
+  }
+};

test/core/fixtures/transformation/jscript/arrow-function/exec.js

@@ -0,0 +1,9 @@
+class MyClass {
+  test() {
+    const that = this;
+    const func = () => this === that;
+    return func();
+  }
+}
+
+assert(new MyClass().test());