From 1a30f1aafc09cb139220ef574e6ba0bf4afc22aa Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Sat, 11 Apr 2015 18:13:47 -0700
Subject: [PATCH] fix regression with completion records for assignment
 expressions - fixes #1204

---
 .../transformers/es6/destructuring.js             | 10 ++++++++--
 src/babel/traversal/path/index.js                 | 15 ++++++++++++++-
 .../actual.js                                     |  2 ++
 .../expected.js                                   |  7 +++++++
 .../assignment-expression/expected.js             |  4 ++--
 5 files changed, 33 insertions(+), 5 deletions(-)
 create mode 100644 test/core/fixtures/transformation/es6.destructuring/assignment-expression-completion-record/actual.js
 create mode 100644 test/core/fixtures/transformation/es6.destructuring/assignment-expression-completion-record/expected.js

diff --git a/src/babel/transformation/transformers/es6/destructuring.js b/src/babel/transformation/transformers/es6/destructuring.js
index 510eebfee7..3d774451d7 100644
--- a/src/babel/transformation/transformers/es6/destructuring.js
+++ b/src/babel/transformation/transformers/es6/destructuring.js
@@ -126,10 +126,11 @@ export function AssignmentExpression(node, parent, scope, file) {
   if (!t.isPattern(node.left)) return;
 
   var ref = scope.generateUidIdentifier("temp");
-  scope.push({ id: ref });
 
   var nodes = [];
-  nodes.push(t.expressionStatement(t.assignmentExpression("=", ref, node.right)));
+  nodes.push(t.variableDeclaration("var", [
+    t.variableDeclarator(ref, node.right)
+  ]));
 
   var destructuring = new DestructuringTransformer({
     operator: node.operator,
@@ -137,6 +138,11 @@ export function AssignmentExpression(node, parent, scope, file) {
     scope: scope,
     nodes: nodes
   });
+
+  if (t.isArrayExpression(node.right)) {
+    destructuring.arrays[ref.name] = true;
+  }
+
   destructuring.init(node.left, ref);
 
   nodes.push(t.expressionStatement(ref));
diff --git a/src/babel/traversal/path/index.js b/src/babel/traversal/path/index.js
index 0356e9929d..b7476c109d 100644
--- a/src/babel/traversal/path/index.js
+++ b/src/babel/traversal/path/index.js
@@ -132,11 +132,24 @@ export default class TraversalPath {
 
   _maybePopFromStatements(nodes) {
     var last = nodes[nodes.length - 1];
-    if (t.isExpressionStatement(last) && t.isIdentifier(last.expression)) {
+    if (t.isExpressionStatement(last) && t.isIdentifier(last.expression) && !this.isCompletionRecord()) {
       nodes.pop();
     }
   }
 
+  isCompletionRecord() {
+    var path = this;
+
+    do {
+      var container = path.container;
+      if (Array.isArray(container) && path.key !== container.length - 1) {
+        return false;
+      }
+    } while (path = path.parentPath && !path.isProgram());
+
+    return true;
+  }
+
   isStatementOrBlock() {
     if (t.isLabeledStatement(this.parent) || t.isBlockStatement(this.container)) {
       return false;
diff --git a/test/core/fixtures/transformation/es6.destructuring/assignment-expression-completion-record/actual.js b/test/core/fixtures/transformation/es6.destructuring/assignment-expression-completion-record/actual.js
new file mode 100644
index 0000000000..63c2b6595f
--- /dev/null
+++ b/test/core/fixtures/transformation/es6.destructuring/assignment-expression-completion-record/actual.js
@@ -0,0 +1,2 @@
+var x, y;
+[x, y] = [1, 2];
diff --git a/test/core/fixtures/transformation/es6.destructuring/assignment-expression-completion-record/expected.js b/test/core/fixtures/transformation/es6.destructuring/assignment-expression-completion-record/expected.js
new file mode 100644
index 0000000000..8f31c828a4
--- /dev/null
+++ b/test/core/fixtures/transformation/es6.destructuring/assignment-expression-completion-record/expected.js
@@ -0,0 +1,7 @@
+"use strict";
+
+var x, y;
+var _temp = [1, 2];
+x = _temp[0];
+y = _temp[1];
+_temp;
diff --git a/test/core/fixtures/transformation/es6.destructuring/assignment-expression/expected.js b/test/core/fixtures/transformation/es6.destructuring/assignment-expression/expected.js
index 9ef5dc3448..72bddcac55 100644
--- a/test/core/fixtures/transformation/es6.destructuring/assignment-expression/expected.js
+++ b/test/core/fixtures/transformation/es6.destructuring/assignment-expression/expected.js
@@ -1,5 +1,5 @@
 "use strict";
 
-var _temp, _temp2;
+var _temp;
 
-console.log((_temp = [123], _temp2 = babelHelpers.slicedToArray(_temp, 1), x = _temp2[0], _temp));
+console.log((_temp = [123], x = _temp[0], _temp));