Merge pull request airbnb#619 from kesne/jgens/react-cleanup

[eslint config] [breaking] [react] Minor cleanup for the React styleguide

Author: ljharb

packages/eslint-config-airbnb/rules/react.js

@@ -21,6 +21,9 @@ module.exports = {
     // Validate props indentation in JSX
     // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-indent-props.md
     'react/jsx-indent-props': [2, 2],
+    // Prevent usage of .bind() and arrow functions in JSX props
+    // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-no-bind.md
+    'react/jsx-no-bind': 2,
     // Prevent duplicate props in JSX
     // https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-no-duplicate-props.md
     'react/jsx-no-duplicate-props': 0,

react/README.md

@@ -56,10 +56,10 @@
 
     ```javascript
     // bad
-    const reservationCard = require('./ReservationCard');
+    import reservationCard from './ReservationCard';
 
     // good
-    const ReservationCard = require('./ReservationCard');
+    import ReservationCard from './ReservationCard';
 
     // bad
     const ReservationItem = <ReservationCard />;
@@ -68,17 +68,17 @@
     const reservationItem = <ReservationCard />;
     ```
 
-  **Component Naming**: Use the filename as the component name. For example, `ReservationCard.jsx` should have a reference name of `ReservationCard`. However, for root components of a directory, use `index.jsx` as the filename and use the directory name as the component name:
+  - **Component Naming**: Use the filename as the component name. For example, `ReservationCard.jsx` should have a reference name of `ReservationCard`. However, for root components of a directory, use `index.jsx` as the filename and use the directory name as the component name:
 
     ```javascript
     // bad
-    const Footer = require('./Footer/Footer.jsx')
+    import Footer from './Footer/Footer';
 
     // bad
-    const Footer = require('./Footer/index.jsx')
+    import Footer from './Footer/index';
 
     // good
-    const Footer = require('./Footer')
+    import Footer from './Footer';
     ```
 
 ## Declaration
@@ -186,14 +186,30 @@
     />
     ```
 
+  - Omit the value of the prop when it is explicitly `true`.
+
+  eslint rules: [`react/jsx-boolean-value`](https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-boolean-value.md).
+
+    ```javascript
+    // bad
+    <Foo
+      hidden={true}
+    />
+
+    // good
+    <Foo
+      hidden
+    />
+    ```
+
 ## Parentheses
 
   - Wrap JSX tags in parentheses when they span more than one line.
 
   eslint rules: [`react/wrap-multilines`](https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/wrap-multilines.md).
 
     ```javascript
-    /// bad
+    // bad
     render() {
       return <MyComponent className="long body" foo="bar">
                <MyChild />
@@ -249,14 +265,50 @@
 
 ## Methods
 
+  - Bind event handlers for the render method in the constructor.
+
+  > Why? A bind call in a the render path create a brand new function on every single render.
+
+  eslint rules: [`react/jsx-no-bind`](https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-no-bind.md).
+
+    ```javascript
+    // bad
+    class extends React.Component {
+      onClickDiv() {
+        // do stuff
+      }
+
+      render() {
+        return <div onClick={this.onClickDiv.bind(this)} />
+      }
+    }
+
+    // good
+    class extends React.Component {
+      constructor(props) {
+        super(props);
+
+        this.onClickDiv = this.onClickDiv.bind(this);
+      }
+
+      onClickDiv() {
+        // do stuff
+      }
+
+      render() {
+        return <div onClick={this.onClickDiv} />
+      }
+    }
+    ```
+
   - Do not use underscore prefix for internal methods of a React component.
 
     ```javascript
     // bad
     React.createClass({
       _onClickSubmit() {
         // do stuff
-      }
+      },
 
       // other stuff
     });
@@ -268,7 +320,7 @@
       }
 
       // other stuff
-    });
+    }
     ```
 
 ## Ordering