From fbd9c35dd37c2466b809a89c79703583de77d275 Mon Sep 17 00:00:00 2001
From: Harrison Shoff <hi@hshoff.com>
Date: Sun, 14 Feb 2016 11:14:38 -0800
Subject: [PATCH] [eslint-v2][arrays] add array-callback-return rule

---
 README.md                                     | 45 +++++++++++++++++++
 .../rules/best-practices.js                   |  3 ++
 2 files changed, 48 insertions(+)

diff --git a/README.md b/README.md
index 46e78358..b52dbdcc 100644
--- a/README.md
+++ b/README.md
@@ -346,6 +346,51 @@ Other Style Guides
     const nodes = Array.from(foo);
     ```
 
+  - [4.5](#4.5) <a name='4.5'></a> Use return statements in array method callbacks. It's ok to omit the return if the function body consists of a single statement following [8.2](#8.2). eslint: [array-callback-return](http://eslint.org/docs/rules/array-callback-return)
+
+    ```javascript
+    // good
+    [1, 2, 3].map((x) => {
+      const y = x + 1;
+      return x * y;
+    });
+
+    // good
+    [1, 2, 3].map(x => x + 1);
+
+    // bad
+    const flat = {};
+    [[0, 1], [2, 3], [4, 5]].reduce((memo, item, index) => {
+      const flatten = memo.concat(item);
+      flat[index] = memo.concat(item);
+    });
+
+    // good
+    const flat = {};
+    [[0, 1], [2, 3], [4, 5]].reduce((memo, item, index) => {
+      const flatten = memo.concat(item);
+      flat[index] = flatten;
+      return flatten;
+    });
+
+    // bad
+    [1, 2, 3].filter((x) => {
+      if (x > 2) {
+        return true;
+      } else {
+        return false;
+      }
+    });
+
+    // good
+    [1, 2, 3].filter((x) => {
+      if (x > 2) {
+        return true;
+      }
+      return false;
+    });
+    ```
+
 **[⬆ back to top](#table-of-contents)**
 
 ## Destructuring
diff --git a/packages/eslint-config-airbnb/rules/best-practices.js b/packages/eslint-config-airbnb/rules/best-practices.js
index 5a50af00..6f667924 100644
--- a/packages/eslint-config-airbnb/rules/best-practices.js
+++ b/packages/eslint-config-airbnb/rules/best-practices.js
@@ -2,6 +2,9 @@ module.exports = {
   'rules': {
     // enforces getter/setter pairs in objects
     'accessor-pairs': 0,
+    // enforces return statements in callbacks of array's methods
+    // http://eslint.org/docs/rules/array-callback-return
+    'array-callback-return': 2,
     // treat var statements as if they were block scoped
     'block-scoped-var': 2,
     // specify the maximum cyclomatic complexity allowed in a program