Merge pull request #3586 from loganfsmyth/fix-retainLines-generator-issue

Avoid duplicated identifier sharing location - fixes T7436

packages/babel-plugin-transform-regenerator/src/hoist.js

@@ -26,7 +26,9 @@ exports.hoist = function(funPath) {
     let exprs = [];
 
     vdec.declarations.forEach(function(dec) {
-      vars[dec.id.name] = dec.id;
+      // Note: We duplicate 'dec.id' here to ensure that the variable declaration IDs don't
+      // have the same 'loc' value, since that can make sourcemaps and retainLines behave poorly.
+      vars[dec.id.name] = t.identifier(dec.id.name);
 
       if (dec.init) {
         exprs.push(t.assignmentExpression(

packages/babel-plugin-transform-regenerator/test/fixtures/variable-renaming/retain-lines/actual.js

@@ -0,0 +1,7 @@
+var func = function * (){
+  yield obj
+      .method()
+      .method2();
+
+  const actual = true;
+};

packages/babel-plugin-transform-regenerator/test/fixtures/variable-renaming/retain-lines/expected.js

@@ -0,0 +1,6 @@
+var func = regeneratorRuntime.mark(function _callee() {var actual;return regeneratorRuntime.wrap(function _callee$(_context) {while (1) switch (_context.prev = _context.next) {case 0:_context.next = 2;return (
+                    obj.
+                    method().
+                    method2());case 2:
+
+                actual = true;case 3:case "end":return _context.stop();}}, _callee, this);});

packages/babel-plugin-transform-regenerator/test/fixtures/variable-renaming/retain-lines/options.json

@@ -0,0 +1,6 @@
+{
+  "plugins": [
+    "transform-regenerator"
+  ],
+  "retainLines": true
+}