Add ignoreStateless option to no-multi-comp (fixes #290)

Author: yannickcr

docs/rules/no-multi-comp.md

@@ -32,6 +32,41 @@ var HelloJohn = React.createClass({
 });
 ```
 
+## Rule Options
+
+```js
+...
+"no-multi-comp": [<enabled>, { "ignoreStateless": <boolean> }]
+...
+```
+
+### `ignoreStateless`
+
+When `true` the rule will ignore stateless components and will allow you to have multiple stateless components, or one statefull component and some stateless components in the same file.
+
+The following patterns are considered okay and do not cause warnings:
+
+```js
+function Hello(props) {
+  return <div>Hello {props.name}</div>;
+}
+function HelloAgain(props) {
+  return <div>Hello again {props.name}</div>;
+}
+```
+
+```js
+function Hello(props) {
+  return <div>Hello {props.name}</div>;
+}
+class HelloJohn extends React.Component {
+  render() {
+    return <Hello name="John" />;
+  }
+}
+module.exports = HelloJohn;
+```
+
 ## When Not To Use It
 
 If you prefer to declare multiple components per files you can disable this rule.

lib/rules/no-multi-comp.js

@@ -12,8 +12,20 @@ var Components = require('../util/Components');
 
 module.exports = Components.detect(function(context, components) {
 
+  var configuration = context.options[0] || {};
+  var ignoreStateless = configuration.ignoreStateless || false;
+
   var MULTI_COMP_MESSAGE = 'Declare only one React component per file';
 
+  /**
+   * Checks if the component is ignored
+   * @param {Object} component The component being checked.
+   * @returns {Boolean} True if the component is ignored, false if not.
+   */
+  function isIgnored(component) {
+    return ignoreStateless === true && /Function/.test(component.node.type);
+  }
+
   // --------------------------------------------------------------------------
   // Public
   // --------------------------------------------------------------------------
@@ -28,7 +40,7 @@ module.exports = Components.detect(function(context, components) {
       var i = 0;
 
       for (var component in list) {
-        if (!list.hasOwnProperty(component) || ++i === 1) {
+        if (!list.hasOwnProperty(component) || isIgnored(list[component]) || ++i === 1) {
           continue;
         }
         context.report(list[component].node, MULTI_COMP_MESSAGE);
@@ -37,4 +49,13 @@ module.exports = Components.detect(function(context, components) {
   };
 });
 
-module.exports.schema = [];
+module.exports.schema = [{
+  type: 'object',
+  properties: {
+    ignoreStateless: {
+      default: false,
+      type: 'boolean'
+    }
+  },
+  additionalProperties: false
+}];

tests/lib/rules/no-multi-comp.js

@@ -76,6 +76,37 @@ ruleTester.run('no-multi-comp', rule, {
       '};'
     ].join('\n'),
     parser: 'babel-eslint'
+  }, {
+    code: [
+      'function Hello(props) {',
+      '  return <div>Hello {props.name}</div>;',
+      '}',
+      'function HelloAgain(props) {',
+      '  return <div>Hello again {props.name}</div>;',
+      '}'
+    ].join('\n'),
+    parser: 'babel-eslint',
+    options: [{
+      ignoreStateless: true
+    }]
+  }, {
+    code: [
+      'function Hello(props) {',
+      '  return <div>Hello {props.name}</div>;',
+      '}',
+      'class HelloJohn extends React.Component {',
+      '  render() {',
+      '    return <Hello name="John" />;',
+      '  }',
+      '}'
+    ].join('\r'),
+    ecmaFeatures: {
+      classes: true,
+      jsx: true
+    },
+    options: [{
+      ignoreStateless: true
+    }]
   }],
 
   invalid: [{
@@ -127,5 +158,38 @@ ruleTester.run('no-multi-comp', rule, {
       message: 'Declare only one React component per file',
       line: 11
     }]
+  }, {
+    code: [
+      'function Hello(props) {',
+      '  return <div>Hello {props.name}</div>;',
+      '}',
+      'function HelloAgain(props) {',
+      '  return <div>Hello again {props.name}</div>;',
+      '}'
+    ].join('\n'),
+    parser: 'babel-eslint',
+    errors: [{
+      message: 'Declare only one React component per file',
+      line: 4
+    }]
+  }, {
+    code: [
+      'function Hello(props) {',
+      '  return <div>Hello {props.name}</div>;',
+      '}',
+      'class HelloJohn extends React.Component {',
+      '  render() {',
+      '    return <Hello name="John" />;',
+      '  }',
+      '}'
+    ].join('\r'),
+    ecmaFeatures: {
+      classes: true,
+      jsx: true
+    },
+    errors: [{
+      message: 'Declare only one React component per file',
+      line: 4
+    }]
   }]
 });