fix regression with completion records for assignment expressions - fixes #1204

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));

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;