'use strict'; const {hasSideEffect, isSemicolonToken} = require('@eslint-community/eslint-utils'); const { getCallExpressionTokens, getCallExpressionArgumentsText, } = require('./utils/index.js'); const isSameReference = require('./utils/is-same-reference.js'); const {isNodeMatches} = require('./utils/is-node-matches.js'); const getPreviousNode = require('./utils/get-previous-node.js'); const {isMethodCall} = require('./ast/index.js'); const ERROR = 'error'; const SUGGESTION = 'suggestion'; const messages = { [ERROR]: 'Do not call `Array#push()` multiple times.', [SUGGESTION]: 'Merge with previous one.', }; const isArrayPushCall = node => node && node.parent.type === 'ExpressionStatement' && node.parent.expression === node && isMethodCall(node, { method: 'push', optionalCall: false, optionalMember: false, }); function getFirstArrayPushCall(secondCall, sourceCode) { const firstCall = getPreviousNode(secondCall.parent, sourceCode)?.expression; if (isArrayPushCall(firstCall)) { return firstCall; } } function create(context) { const {ignore} = { ignore: [], ...context.options[0], }; const ignoredObjects = [ 'stream', 'this', 'this.stream', 'process.stdin', 'process.stdout', 'process.stderr', ...ignore, ]; const {sourceCode} = context; return { CallExpression(secondCall) { if (!isArrayPushCall(secondCall)) { return; } const secondCallArray = secondCall.callee.object; if (isNodeMatches(secondCallArray, ignoredObjects)) { return; } const firstCall = getFirstArrayPushCall(secondCall, sourceCode); if (!firstCall) { return; } const firstCallArray = firstCall.callee.object; // Not same array if (!isSameReference(firstCallArray, secondCallArray)) { return; } const secondCallArguments = secondCall.arguments; const problem = { node: secondCall.callee.property, messageId: ERROR, }; const fix = function * (fixer) { if (secondCallArguments.length > 0) { const text = getCallExpressionArgumentsText(sourceCode, secondCall); const { trailingCommaToken, closingParenthesisToken, } = getCallExpressionTokens(sourceCode, firstCall); yield ( trailingCommaToken ? fixer.insertTextAfter(trailingCommaToken, ` ${text}`) : fixer.insertTextBefore(closingParenthesisToken, firstCall.arguments.length > 0 ? `, ${text}` : text) ); } const firstExpression = firstCall.parent; const secondExpression = secondCall.parent; const shouldKeepSemicolon = !isSemicolonToken(sourceCode.getLastToken(firstExpression)) && isSemicolonToken(sourceCode.getLastToken(secondExpression)); yield fixer.replaceTextRange( [firstExpression.range[1], secondExpression.range[1]], shouldKeepSemicolon ? ';' : '', ); }; if (secondCallArguments.some(element => hasSideEffect(element, sourceCode))) { problem.suggest = [ { messageId: SUGGESTION, fix, }, ]; } else { problem.fix = fix; } return problem; }, }; } const schema = [ { type: 'object', additionalProperties: false, properties: { ignore: { type: 'array', uniqueItems: true, }, }, }, ]; /** @type {import('eslint').Rule.RuleModule} */ module.exports = { create, meta: { type: 'suggestion', docs: { description: 'Enforce combining multiple `Array#push()` into one call.', recommended: true, }, fixable: 'code', hasSuggestions: true, schema, messages, }, };