properly replace labels in spec for of transformer - fixes #913, closes #914

src/babel/transformation/transformers/es6/for-of.js

@@ -32,7 +32,11 @@ export function ForOfStatement(node, parent, scope, file) {
   // todo: find out why this is necessary? #538
   loop._scopeInfo = node._scopeInfo;
 
-  return build.node;
+  if (build.replaceParent) {
+    this.parentPath.node = build.node;
+  } else {
+    return build.node;
+  }
 }
 
 var breakVisitor = {
@@ -97,7 +101,9 @@ var loose = function (node, parent, scope, file) {
 
   scope.traverse(node, breakVisitor, {
     iteratorKey: iteratorKey,
-    wrapReturn:  function (node) {
+    label:       t.isLabeledStatement(parent) && parent.label.name,
+
+    wrapReturn: function (node) {
       return t.ifStatement(
         t.logicalExpression(
           "&&",
@@ -105,8 +111,7 @@ var loose = function (node, parent, scope, file) {
           t.memberExpression(iteratorKey, t.identifier("return")
         )
       ), node);
-    },
-    label:       t.isLabeledStatement(parent) && parent.label.name
+    }
   });
 
   //
@@ -119,6 +124,8 @@ var loose = function (node, parent, scope, file) {
 };
 
 var spec = function (node, parent, scope, file) {
+
+
   var left = node.left;
   var declar;
 
@@ -151,14 +158,22 @@ var spec = function (node, parent, scope, file) {
     BODY:                   null
   });
 
-  var loop = template[3].block.body[0];
+  var isLabeledParent = t.isLabeledStatement(parent);
+
+  var tryBody = template[3].block.body;
+  var loop = tryBody[0];
+
+  if (isLabeledParent) {
+    tryBody[0] = t.labeledStatement(parent.label, loop);
+  }
 
   //
 
   scope.traverse(node, breakVisitor, {
     iteratorKey: iteratorKey,
-    label:       t.isLabeledStatement(parent) && parent.label.name,
-    wrapReturn:  function (node) {
+    label:       isLabeledParent && parent.label.name,
+
+    wrapReturn: function (node) {
       return t.ifStatement(t.memberExpression(iteratorKey, t.identifier("return")), node);
     }
   });
@@ -166,8 +181,9 @@ var spec = function (node, parent, scope, file) {
   //
 
   return {
-    declar: declar,
-    loop:   loop,
-    node:   template
+    replaceParent: isLabeledParent,
+    declar:        declar,
+    loop:          loop,
+    node:          template
   };
 };

src/babel/types/builder-keys.json

@@ -84,6 +84,11 @@
     "name": null
   },
 
+  "LabeledStatement": {
+    "label": null,
+    "body": null
+  },
+
   "Literal": {
     "value": null
   },

test/fixtures/transformation/es6-for-of/break/expected.js

@@ -2,89 +2,89 @@
 
 // labels
 
-foo: {
-  var _iteratorNormalCompletion = true;
-  var _didIteratorError = false;
-  var _iteratorError = undefined;
+var _iteratorNormalCompletion = true;
+var _didIteratorError = false;
+var _iteratorError = undefined;
 
-  try {
-    for (var _iterator = foo()[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
-      var x = _step.value;
+try {
+  foo: for (var _iterator = foo()[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
+    var x = _step.value;
 
-      while (true) {
-        if (_iterator["return"]) _iterator["return"]();
-
-        break foo;
-      }
-    }
-  } catch (err) {
-    _didIteratorError = true;
-    _iteratorError = err;
-  } finally {
-    try {
-      if (!_iteratorNormalCompletion && _iterator["return"]) {
-        _iterator["return"]();
-      }
-    } finally {
-      if (_didIteratorError) {
-        throw _iteratorError;
-      }
-    }
-  }
-}foo: {
-  var _iteratorNormalCompletion2 = true;
-  var _didIteratorError2 = false;
-  var _iteratorError2 = undefined;
-
-  try {
-    for (var _iterator2 = foo()[Symbol.iterator](), _step2; !(_iteratorNormalCompletion2 = (_step2 = _iterator2.next()).done); _iteratorNormalCompletion2 = true) {
-      var x = _step2.value;
-
-      while (true) {
-        break;
-      }
-    }
-  } catch (err) {
-    _didIteratorError2 = true;
-    _iteratorError2 = err;
-  } finally {
-    try {
-      if (!_iteratorNormalCompletion2 && _iterator2["return"]) {
-        _iterator2["return"]();
-      }
-    } finally {
-      if (_didIteratorError2) {
-        throw _iteratorError2;
-      }
-    }
-  }
-}foo: {
-  var _iteratorNormalCompletion3 = true;
-  var _didIteratorError3 = false;
-  var _iteratorError3 = undefined;
-
-  try {
-    for (var _iterator3 = foo()[Symbol.iterator](), _step3; !(_iteratorNormalCompletion3 = (_step3 = _iterator3.next()).done); _iteratorNormalCompletion3 = true) {
-      var x = _step3.value;
-      if (_iterator3["return"]) _iterator3["return"]();
+    while (true) {
+      if (_iterator["return"]) _iterator["return"]();
 
       break foo;
     }
-  } catch (err) {
-    _didIteratorError3 = true;
-    _iteratorError3 = err;
+  }
+} catch (err) {
+  _didIteratorError = true;
+  _iteratorError = err;
+} finally {
+  try {
+    if (!_iteratorNormalCompletion && _iterator["return"]) {
+      _iterator["return"]();
+    }
   } finally {
-    try {
-      if (!_iteratorNormalCompletion3 && _iterator3["return"]) {
-        _iterator3["return"]();
-      }
-    } finally {
-      if (_didIteratorError3) {
-        throw _iteratorError3;
-      }
+    if (_didIteratorError) {
+      throw _iteratorError;
     }
   }
-} // basic
+}
+
+var _iteratorNormalCompletion2 = true;
+var _didIteratorError2 = false;
+var _iteratorError2 = undefined;
+
+try {
+  foo: for (var _iterator2 = foo()[Symbol.iterator](), _step2; !(_iteratorNormalCompletion2 = (_step2 = _iterator2.next()).done); _iteratorNormalCompletion2 = true) {
+    var x = _step2.value;
+
+    while (true) {
+      break;
+    }
+  }
+} catch (err) {
+  _didIteratorError2 = true;
+  _iteratorError2 = err;
+} finally {
+  try {
+    if (!_iteratorNormalCompletion2 && _iterator2["return"]) {
+      _iterator2["return"]();
+    }
+  } finally {
+    if (_didIteratorError2) {
+      throw _iteratorError2;
+    }
+  }
+}
+
+var _iteratorNormalCompletion3 = true;
+var _didIteratorError3 = false;
+var _iteratorError3 = undefined;
+
+try {
+  foo: for (var _iterator3 = foo()[Symbol.iterator](), _step3; !(_iteratorNormalCompletion3 = (_step3 = _iterator3.next()).done); _iteratorNormalCompletion3 = true) {
+    var x = _step3.value;
+    if (_iterator3["return"]) _iterator3["return"]();
+
+    break foo;
+  }
+} catch (err) {
+  _didIteratorError3 = true;
+  _iteratorError3 = err;
+} finally {
+  try {
+    if (!_iteratorNormalCompletion3 && _iterator3["return"]) {
+      _iterator3["return"]();
+    }
+  } finally {
+    if (_didIteratorError3) {
+      throw _iteratorError3;
+    }
+  }
+}
+
+// basic
 
 var _iteratorNormalCompletion4 = true;
 var _didIteratorError4 = false;
@@ -137,4 +137,4 @@ try {
       throw _iteratorError5;
     }
   }
-}
+}