112 lines
3.5 KiB
JavaScript
112 lines
3.5 KiB
JavaScript
/**
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* @author Toru Nagashima <https://github.com/mysticatea>
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* See LICENSE file in root directory for full license.
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*/
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"use strict"
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const { isArrowToken } = require("eslint-utils")
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module.exports = {
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meta: {
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docs: {
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description: "disallow arrow function expressions.",
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category: "ES2015",
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recommended: false,
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url:
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"http://mysticatea.github.io/eslint-plugin-es/rules/no-arrow-functions.html",
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},
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fixable: "code",
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schema: [],
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messages: {
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forbidden: "ES2015 arrow function expressions are forbidden.",
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},
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},
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create(context) {
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const sourceCode = context.getSourceCode()
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/**
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* ArrowFunctionExpression to FunctionExpression
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* @param {Node} node ArrowFunctionExpression Node
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* @returns {string} function expression text
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*/
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function toFunctionExpression(node) {
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const params = node.params
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const paramText = params.length
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? sourceCode.text.slice(
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params[0].range[0],
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params[params.length - 1].range[1]
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)
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: ""
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const arrowToken = sourceCode.getTokenBefore(
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node.body,
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isArrowToken
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)
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const preText = sourceCode.text.slice(
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arrowToken.range[1],
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node.body.range[0]
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)
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const bodyText = sourceCode.text.slice(
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arrowToken.range[1],
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node.range[1]
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)
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if (node.body.type === "BlockStatement") {
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return `function(${paramText})${bodyText}`
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}
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if (preText.includes("\n")) {
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return `function(${paramText}){return(${bodyText})}`
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}
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return `function(${paramText}){return ${bodyText}}`
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}
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/**
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* Report that ArrowFunctionExpression is being used
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* @param {Node} node ArrowFunctionExpression Node
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* @param {boolean} hasThis Whether `this` is referenced in` function` scope
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* @param {boolean} hasSuper Whether `super` is referenced in` function` scope
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* @returns {void}
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*/
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function report(node, hasThis, hasSuper) {
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context.report({
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node,
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messageId: "forbidden",
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fix(fixer) {
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if (hasSuper) {
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return undefined
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}
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const functionText = toFunctionExpression(node)
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return fixer.replaceText(
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node,
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hasThis ? `${functionText}.bind(this)` : functionText
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)
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},
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})
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}
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let stack = { upper: null, hasThis: false, hasSuper: false }
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return {
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":function"() {
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stack = { upper: stack, hasThis: false, hasSuper: false }
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},
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":function:exit"(node) {
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const { hasThis, hasSuper } = stack
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stack = stack.upper
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if (node.type === "ArrowFunctionExpression") {
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report(node, hasThis, hasSuper)
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stack.hasThis = stack.hasThis || hasThis
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stack.hasSuper = stack.hasSuper || hasSuper
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}
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},
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ThisExpression() {
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stack.hasThis = true
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},
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Super() {
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stack.hasSuper = true
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},
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}
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},
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}
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