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Add react/no-redundant-should-component-update
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,64 @@ | ||
| # Prevent usage of shouldComponentUpdate when extending React.PureComponent (react/no-redundant-should-component-update) | ||
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| Warns if you have `shouldComponentUpdate` defined when defining a component that extends React.PureComponent. | ||
| While having `shouldComponentUpdate` will still work, it becomes pointless to extend PureComponent. | ||
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| ## Rule Details | ||
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| The following patterns are considered warnings: | ||
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| ```jsx | ||
| class Foo extends React.PureComponent { | ||
| shouldComponentUpdate() { | ||
| // do check | ||
| } | ||
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| render() { | ||
| return <div>Radical!</div> | ||
| } | ||
| } | ||
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| function Bar() { | ||
| return class Baz extends React.PureComponent { | ||
| shouldComponentUpdate() { | ||
| // do check | ||
| } | ||
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| render() { | ||
| return <div>Groovy!</div> | ||
| } | ||
| } | ||
| } | ||
| ``` | ||
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| The following patterns are not considered warnings: | ||
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| ```jsx | ||
| class Foo extends React.Component { | ||
| shouldComponentUpdate() { | ||
| // do check | ||
| } | ||
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| render() { | ||
| return <div>Radical!</div> | ||
| } | ||
| } | ||
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| function Bar() { | ||
| return class Baz extends React.Component { | ||
| shouldComponentUpdate() { | ||
| // do check | ||
| } | ||
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| render() { | ||
| return <div>Groovy!</div> | ||
| } | ||
| } | ||
| } | ||
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| class Qux extends React.PureComponent { | ||
| render() { | ||
| return <div>Tubular!</div> | ||
| } | ||
| } | ||
| ``` |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,109 @@ | ||
| /** | ||
| * @fileoverview Flag shouldComponentUpdate when extending PureComponent | ||
| */ | ||
| 'use strict'; | ||
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| var Components = require('../util/Components'); | ||
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| function errorMessage(node) { | ||
| return `${node} does not need shouldComponentUpdate when extending React.PureComponent.`; | ||
| } | ||
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| // ------------------------------------------------------------------------------ | ||
| // Rule Definition | ||
| // ------------------------------------------------------------------------------ | ||
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| module.exports = { | ||
| meta: { | ||
| docs: { | ||
| description: 'Flag shouldComponentUpdate when extending PureComponent', | ||
| category: 'Possible Errors', | ||
| recommended: false | ||
| }, | ||
| schema: [] | ||
| }, | ||
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| create: Components.detect(function(context, components, utils) { | ||
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| /** | ||
| * Get properties name | ||
| * @param {Object} node - Property. | ||
| * @returns {String} Property name. | ||
| */ | ||
| function getPropertyName(node) { | ||
| if (node.key) { | ||
| return node.key.name; | ||
| } else if (node.type === 'ClassProperty') { | ||
| // Special case for class properties | ||
| // (babel-eslint does not expose property name so we have to rely on tokens) | ||
| var tokens = context.getFirstTokens(node, 2); | ||
| return tokens[1] && tokens[1].type === 'Identifier' ? tokens[1].value : tokens[0].value; | ||
| } | ||
| return ''; | ||
| } | ||
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| /** | ||
| * Get properties for a given AST node | ||
| * @param {ASTNode} node The AST node being checked. | ||
| * @returns {Array} Properties array. | ||
| */ | ||
| function getComponentProperties(node) { | ||
| switch (node.type) { | ||
| case 'ClassExpression': | ||
| case 'ClassDeclaration': | ||
| return node.body.body; | ||
| default: | ||
| return []; | ||
| } | ||
| } | ||
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| /** | ||
| * Checks for shouldComponentUpdate property | ||
| * @param {ASTNode} node The AST node being checked. | ||
| * @returns {Boolean} Whether or not the property exists. | ||
| */ | ||
| function hasShouldComponentUpdate(node) { | ||
| var properties = getComponentProperties(node); | ||
| return properties.some(function(property) { | ||
| var name = getPropertyName(property); | ||
| return name === 'shouldComponentUpdate'; | ||
| }); | ||
| } | ||
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| /** | ||
| * Get name of node if available | ||
| * @param {ASTNode} node The AST node being checked. | ||
| * @return {String} The name of the node | ||
| */ | ||
| function getNodeName(node) { | ||
| if (node.id) { | ||
| return node.id.name; | ||
| } else if (node.parent && node.parent.id) { | ||
| return node.parent.id.name; | ||
| } | ||
| return ''; | ||
| } | ||
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| /** | ||
| * Checks for violation of rule | ||
| * @param {ASTNode} node The AST node being checked. | ||
| */ | ||
| function checkForViolation(node) { | ||
| if (utils.isPureComponent(node)) { | ||
| var hasScu = hasShouldComponentUpdate(node); | ||
| if (hasScu) { | ||
| var className = getNodeName(node); | ||
| context.report({ | ||
| node: node, | ||
| message: errorMessage(className) | ||
| }); | ||
| } | ||
| } | ||
| } | ||
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| return { | ||
| ClassDeclaration: checkForViolation, | ||
| ClassExpression: checkForViolation | ||
| }; | ||
| }) | ||
| }; |
150 changes: 150 additions & 0 deletions
150
tests/lib/rules/no-redundant-should-component-update.js
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,150 @@ | ||
| /** | ||
| * @fileoverview Tests for no-redundant-should-component-update | ||
| */ | ||
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| 'use strict'; | ||
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| // ----------------------------------------------------------------------------- | ||
| // Requirements | ||
| // ----------------------------------------------------------------------------- | ||
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| var rule = require('../../../lib/rules/no-redundant-should-component-update'); | ||
| var RuleTester = require('eslint').RuleTester; | ||
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| var parserOptions = { | ||
| ecmaVersion: 6, | ||
| ecmaFeatures: { | ||
| experimentalObjectRestSpread: true, | ||
| jsx: true | ||
| } | ||
| }; | ||
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| function errorMessage(node) { | ||
| return `${node} does not need shouldComponentUpdate when extending React.PureComponent.`; | ||
| } | ||
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| // ----------------------------------------------------------------------------- | ||
| // Tests | ||
| // ----------------------------------------------------------------------------- | ||
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| var ruleTester = new RuleTester(); | ||
| ruleTester.run('no-redundant-should-component-update', rule, { | ||
| valid: [ | ||
| { | ||
| code: [ | ||
| 'class Foo extends React.Component {', | ||
| ' shouldComponentUpdate() {', | ||
| ' return true;', | ||
| ' }', | ||
| '}' | ||
| ].join('\n'), | ||
| parserOptions: parserOptions | ||
| }, | ||
| { | ||
| code: [ | ||
| 'class Foo extends React.Component {', | ||
| ' shouldComponentUpdate = () => {', | ||
| ' return true;', | ||
| ' }', | ||
| '}' | ||
| ].join('\n'), | ||
| parser: 'babel-eslint', | ||
| parserOptions: parserOptions | ||
| }, | ||
| { | ||
| code: [ | ||
| 'class Foo extends React.Component {', | ||
| ' shouldComponentUpdate() {', | ||
| ' return true;', | ||
| ' }', | ||
| '}' | ||
| ].join('\n'), | ||
| parserOptions: parserOptions | ||
| }, | ||
| { | ||
| code: [ | ||
| 'function Foo() {', | ||
| ' return class Bar extends React.Component {', | ||
| ' shouldComponentUpdate() {', | ||
| ' return true;', | ||
| ' }', | ||
| ' };', | ||
| '}' | ||
| ].join('\n'), | ||
| parserOptions: parserOptions | ||
| } | ||
| ], | ||
| invalid: [ | ||
| { | ||
| code: [ | ||
| 'class Foo extends React.PureComponent {', | ||
| ' shouldComponentUpdate() {', | ||
| ' return true;', | ||
| ' }', | ||
| '}' | ||
| ].join('\n'), | ||
| errors: [{message: errorMessage('Foo')}], | ||
| parserOptions: parserOptions | ||
| }, | ||
| { | ||
| code: [ | ||
| 'class Foo extends PureComponent {', | ||
| ' shouldComponentUpdate() {', | ||
| ' return true;', | ||
| ' }', | ||
| '}' | ||
| ].join('\n'), | ||
| errors: [{message: errorMessage('Foo')}], | ||
| parserOptions: parserOptions | ||
| }, | ||
| { | ||
| code: [ | ||
| 'class Foo extends React.PureComponent {', | ||
| ' shouldComponentUpdate = () => {', | ||
| ' return true;', | ||
| ' }', | ||
| '}' | ||
| ].join('\n'), | ||
| errors: [{message: errorMessage('Foo')}], | ||
| parser: 'babel-eslint', | ||
| parserOptions: parserOptions | ||
| }, | ||
| { | ||
| code: [ | ||
| 'function Foo() {', | ||
| ' return class Bar extends React.PureComponent {', | ||
| ' shouldComponentUpdate() {', | ||
| ' return true;', | ||
| ' }', | ||
| ' };', | ||
| '}' | ||
| ].join('\n'), | ||
| errors: [{message: errorMessage('Bar')}], | ||
| parserOptions: parserOptions | ||
| }, | ||
| { | ||
| code: [ | ||
| 'function Foo() {', | ||
| ' return class Bar extends PureComponent {', | ||
| ' shouldComponentUpdate() {', | ||
| ' return true;', | ||
| ' }', | ||
| ' };', | ||
| '}' | ||
| ].join('\n'), | ||
| errors: [{message: errorMessage('Bar')}], | ||
| parserOptions: parserOptions | ||
| }, | ||
| { | ||
| code: [ | ||
| 'var Foo = class extends PureComponent {', | ||
| ' shouldComponentUpdate() {', | ||
| ' return true;', | ||
| ' }', | ||
| '}' | ||
| ].join('\n'), | ||
| errors: [{message: errorMessage('Foo')}], | ||
| parserOptions: parserOptions | ||
| } | ||
| ] | ||
| }); |