[eslint config] [base] [breaking] comma-dangle: require trailing commas for functions

README.md

@@ -816,8 +816,8 @@ Other Style Guides
     ```javascript
     // bad
     function foo(bar,
-      baz,
-      quux) {
+                 baz,
+                 quux) {
       // body
     }
 
@@ -2430,6 +2430,56 @@ Other Style Guides
       'Batman',
       'Superman',
     ];
+
+    // bad
+    function createHero(
+      firstName,
+      lastName,
+      inventorOf
+    ) {
+      // does nothing
+    }
+
+    // good
+    function createHero(
+      firstName,
+      lastName,
+      inventorOf,
+    ) {
+      // does nothing
+    }
+
+    // good (note that a comma must not appear after a "rest" element)
+    function createHero(
+      firstName,
+      lastName,
+      inventorOf,
+      ...heroArgs
+    ) {
+      // does nothing
+    }
+
+    // bad
+    createHero(
+      firstName,
+      lastName,
+      inventorOf
+    );
+
+    // good
+    createHero(
+      firstName,
+      lastName,
+      inventorOf,
+    );
+
+    // good (note that a comma must not appear after a "rest" element)
+    createHero(
+      firstName,
+      lastName,
+      inventorOf,
+      ...heroArgs
+    )
     ```
 
 **[⬆ back to top](#table-of-contents)**

packages/eslint-config-airbnb-base/rules/errors.js

@@ -1,7 +1,13 @@
 module.exports = {
   rules: {
     // require trailing commas in multiline object literals
-    'comma-dangle': ['error', 'always-multiline'],
+    'comma-dangle': ['error', {
+      arrays: 'always-multiline',
+      objects: 'always-multiline',
+      imports: 'always-multiline',
+      exports: 'always-multiline',
+      functions: 'always-multiline',
+    }],
 
     // disallow assignment in conditional expressions
     'no-cond-assign': ['error', 'always'],