From 6abee425d3f3ea3cf1a83e726cfbe9a5f1085d1d Mon Sep 17 00:00:00 2001
From: Amjad Masad <amjad.masad@gmail.com>
Date: Wed, 6 Jan 2016 15:59:39 -0800
Subject: [PATCH 1/2] Revert "`babel-types`: add `Binary` alias to
 `AssignmentExpression` definition (fixes T6887)"

This was causing problems with parenthesizing assignment expression
This reverts commit b5cf529d6b342b3dd8dd49c50cc9cd5fed4fc5a7.
---
 packages/babel-generator/src/generators/expressions.js | 4 +---
 packages/babel-generator/src/node/parentheses.js       | 4 ++--
 packages/babel-types/src/definitions/core.js           | 2 +-
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/packages/babel-generator/src/generators/expressions.js b/packages/babel-generator/src/generators/expressions.js
index 2e39f6f070..b5d9ecb860 100644
--- a/packages/babel-generator/src/generators/expressions.js
+++ b/packages/babel-generator/src/generators/expressions.js
@@ -155,10 +155,8 @@ export function AssignmentPattern(node: Object) {
 export function AssignmentExpression(node: Object, parent: Object) {
   // Somewhere inside a for statement `init` node but doesn't usually
   // needs a paren except for `in` expressions: `for (a in b ? a : b;;)`
-  // and for `ObjectPattern`: `({ f } = { f: 2 };`
   let parens = this._inForStatementInit && node.operator === "in" &&
-               !n.needsParens(node, parent) ||
-               t.isObjectPattern(node.left);
+               !n.needsParens(node, parent);
 
   if (parens) {
     this.push("(");
diff --git a/packages/babel-generator/src/node/parentheses.js b/packages/babel-generator/src/node/parentheses.js
index 6a02ba09c8..777bb6e519 100644
--- a/packages/babel-generator/src/node/parentheses.js
+++ b/packages/babel-generator/src/node/parentheses.js
@@ -66,7 +66,7 @@ export function Binary(node: Object, parent: Object): boolean {
     return true;
   }
 
-  if (t.isBinary(parent) && !t.isAssignmentExpression(parent)) {
+  if (t.isBinary(parent)) {
     let parentOp  = parent.operator;
     let parentPos = PRECEDENCE[parentOp];
 
@@ -216,7 +216,7 @@ export function ConditionalExpression(node: Object, parent: Object): boolean {
     return true;
   }
 
-  if (t.isBinary(parent) && !t.isAssignmentExpression(parent)) {
+  if (t.isBinary(parent)) {
     return true;
   }
 
diff --git a/packages/babel-types/src/definitions/core.js b/packages/babel-types/src/definitions/core.js
index 89e5572c78..f817dd5da4 100644
--- a/packages/babel-types/src/definitions/core.js
+++ b/packages/babel-types/src/definitions/core.js
@@ -42,7 +42,7 @@ defineType("AssignmentExpression", {
   },
   builder: ["operator", "left", "right"],
   visitor: ["left", "right"],
-  aliases: ["Binary", "Expression"]
+  aliases: ["Expression"]
 });
 
 defineType("BinaryExpression", {

From ec983b276eb010de789efb00cfa7b7a0138bebf5 Mon Sep 17 00:00:00 2001
From: Amjad Masad <amjad.masad@gmail.com>
Date: Wed, 6 Jan 2016 16:03:45 -0800
Subject: [PATCH 2/2] add assignment expression parentheses test

---
 .../test/fixtures/parentheses/assignment-expression/actual.js  | 3 +++
 .../fixtures/parentheses/assignment-expression/expected.js     | 3 +++
 2 files changed, 6 insertions(+)
 create mode 100644 packages/babel-generator/test/fixtures/parentheses/assignment-expression/actual.js
 create mode 100644 packages/babel-generator/test/fixtures/parentheses/assignment-expression/expected.js

diff --git a/packages/babel-generator/test/fixtures/parentheses/assignment-expression/actual.js b/packages/babel-generator/test/fixtures/parentheses/assignment-expression/actual.js
new file mode 100644
index 0000000000..f1b168c720
--- /dev/null
+++ b/packages/babel-generator/test/fixtures/parentheses/assignment-expression/actual.js
@@ -0,0 +1,3 @@
+1 + (a = 2);
+1 + (a += 2);
+a = a || (a = {});
diff --git a/packages/babel-generator/test/fixtures/parentheses/assignment-expression/expected.js b/packages/babel-generator/test/fixtures/parentheses/assignment-expression/expected.js
new file mode 100644
index 0000000000..f1b168c720
--- /dev/null
+++ b/packages/babel-generator/test/fixtures/parentheses/assignment-expression/expected.js
@@ -0,0 +1,3 @@
+1 + (a = 2);
+1 + (a += 2);
+a = a || (a = {});