/** * @fileoverview Lifecycle methods should be methods on the prototype, not class fields * @author Tan Nguyen */ 'use strict'; const values = require('object.values'); const Components = require('../util/Components'); const astUtil = require('../util/ast'); const componentUtil = require('../util/componentUtil'); const docsUrl = require('../util/docsUrl'); const lifecycleMethods = require('../util/lifecycleMethods'); const report = require('../util/report'); function getText(node) { const params = node.value.params.map((p) => p.name); if (node.type === 'Property') { return `: function(${params.join(', ')}) `; } if (node.type === 'ClassProperty' || node.type === 'PropertyDefinition') { return `(${params.join(', ')}) `; } return null; } const messages = { lifecycle: '{{propertyName}} is a React lifecycle method, and should not be an arrow function or in a class field. Use an instance method instead.', }; module.exports = { meta: { docs: { description: 'Lifecycle methods should be methods on the prototype, not class fields', category: 'Best Practices', recommended: false, url: docsUrl('no-arrow-function-lifecycle'), }, messages, schema: [], fixable: 'code', }, create: Components.detect((context, components) => { /** * @param {Array} properties list of component properties */ function reportNoArrowFunctionLifecycle(properties) { properties.forEach((node) => { if (!node || !node.value) { return; } const propertyName = astUtil.getPropertyName(node); const nodeType = node.value.type; const isLifecycleMethod = ( node.static && !componentUtil.isES5Component(node, context) ? lifecycleMethods.static : lifecycleMethods.instance ).indexOf(propertyName) > -1; if (nodeType === 'ArrowFunctionExpression' && isLifecycleMethod) { const body = node.value.body; const isBlockBody = body.type === 'BlockStatement'; const sourceCode = context.getSourceCode(); let nextComment = []; let previousComment = []; let bodyRange; if (!isBlockBody) { const previousToken = sourceCode.getTokenBefore(body); if (sourceCode.getCommentsBefore) { // eslint >=4.x previousComment = sourceCode.getCommentsBefore(body); } else { // eslint 3.x const potentialComment = sourceCode.getTokenBefore(body, { includeComments: true }); previousComment = previousToken === potentialComment ? [] : [potentialComment]; } if (sourceCode.getCommentsAfter) { // eslint >=4.x nextComment = sourceCode.getCommentsAfter(body); } else { // eslint 3.x const potentialComment = sourceCode.getTokenAfter(body, { includeComments: true }); const nextToken = sourceCode.getTokenAfter(body); nextComment = nextToken === potentialComment ? [] : [potentialComment]; } bodyRange = [ (previousComment.length > 0 ? previousComment[0] : body).range[0], (nextComment.length > 0 ? nextComment[nextComment.length - 1] : body).range[1], ]; } const headRange = [ node.key.range[1], (previousComment.length > 0 ? previousComment[0] : body).range[0], ]; report( context, messages.lifecycle, 'lifecycle', { node, data: { propertyName, }, fix(fixer) { if (!sourceCode.getCommentsAfter) { // eslint 3.x return isBlockBody && fixer.replaceTextRange(headRange, getText(node)); } return [].concat( fixer.replaceTextRange(headRange, getText(node)), isBlockBody ? [] : fixer.replaceTextRange( bodyRange, `{ return ${previousComment.map((x) => sourceCode.getText(x)).join('')}${sourceCode.getText(body)}${nextComment.map((x) => sourceCode.getText(x)).join('')}; }` ) ); }, } ); } }); } return { 'Program:exit'() { values(components.list()).forEach((component) => { const properties = astUtil.getComponentProperties(component.node); reportNoArrowFunctionLifecycle(properties); }); }, }; }), };