'use strict'; const {isMethodCall, isMemberExpression} = require('./ast/index.js'); const {removeArgument} = require('./fix/index.js'); const {isSameReference} = require('./utils/index.js'); const MESSAGE_ID = 'no-length-as-slice-end'; const messages = { [MESSAGE_ID]: 'Passing `….length` as the `end` argument is unnecessary.', }; /** @param {import('eslint').Rule.RuleContext} context */ const create = context => { context.on('CallExpression', callExpression => { if (!isMethodCall(callExpression, { method: 'slice', argumentsLength: 2, optionalCall: false, })) { return; } const secondArgument = callExpression.arguments[1]; const node = secondArgument.type === 'ChainExpression' ? secondArgument.expression : secondArgument; if ( !isMemberExpression(node, {property: 'length', computed: false}) || !isSameReference(callExpression.callee.object, node.object) ) { return; } return { node, messageId: MESSAGE_ID, /** @param {import('eslint').Rule.RuleFixer} fixer */ fix: fixer => removeArgument(fixer, secondArgument, context.sourceCode), }; }); }; /** @type {import('eslint').Rule.RuleModule} */ module.exports = { create, meta: { type: 'suggestion', docs: { description: 'Disallow using `.length` as the `end` argument of `{Array,String,TypedArray}#slice()`.', recommended: true, }, fixable: 'code', messages, }, };