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3ad90a4ac8
Update ESLint and configuration to version 4.0.0. PR-URL: https://github.com/nodejs/node/pull/13645 Reviewed-By: Teddy Katz <teddy.katz@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Refael Ackermann <refack@gmail.com> Reviewed-By: Sam Roberts <vieuxtech@gmail.com> Reviewed-By: Alexey Orlenko <eaglexrlnk@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>
1307 lines
43 KiB
JavaScript
1307 lines
43 KiB
JavaScript
/**
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* @fileoverview Common utils for AST.
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* @author Gyandeep Singh
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*/
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"use strict";
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//------------------------------------------------------------------------------
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// Requirements
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//------------------------------------------------------------------------------
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const esutils = require("esutils");
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const espree = require("espree");
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//------------------------------------------------------------------------------
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// Helpers
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//------------------------------------------------------------------------------
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const anyFunctionPattern = /^(?:Function(?:Declaration|Expression)|ArrowFunctionExpression)$/;
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const anyLoopPattern = /^(?:DoWhile|For|ForIn|ForOf|While)Statement$/;
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const arrayOrTypedArrayPattern = /Array$/;
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const arrayMethodPattern = /^(?:every|filter|find|findIndex|forEach|map|some)$/;
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const bindOrCallOrApplyPattern = /^(?:bind|call|apply)$/;
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const breakableTypePattern = /^(?:(?:Do)?While|For(?:In|Of)?|Switch)Statement$/;
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const thisTagPattern = /^[\s*]*@this/m;
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const COMMENTS_IGNORE_PATTERN = /^\s*(?:eslint|jshint\s+|jslint\s+|istanbul\s+|globals?\s+|exported\s+|jscs)/;
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const LINEBREAKS = new Set(["\r\n", "\r", "\n", "\u2028", "\u2029"]);
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const LINEBREAK_MATCHER = /\r\n|[\r\n\u2028\u2029]/;
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const SHEBANG_MATCHER = /^#!([^\r\n]+)/;
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// A set of node types that can contain a list of statements
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const STATEMENT_LIST_PARENTS = new Set(["Program", "BlockStatement", "SwitchCase"]);
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/**
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* Checks reference if is non initializer and writable.
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* @param {Reference} reference - A reference to check.
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* @param {int} index - The index of the reference in the references.
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* @param {Reference[]} references - The array that the reference belongs to.
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* @returns {boolean} Success/Failure
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* @private
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*/
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function isModifyingReference(reference, index, references) {
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const identifier = reference.identifier;
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/*
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* Destructuring assignments can have multiple default value, so
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* possibly there are multiple writeable references for the same
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* identifier.
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*/
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const modifyingDifferentIdentifier = index === 0 ||
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references[index - 1].identifier !== identifier;
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return (identifier &&
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reference.init === false &&
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reference.isWrite() &&
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modifyingDifferentIdentifier
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);
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}
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/**
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* Checks whether the given string starts with uppercase or not.
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*
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* @param {string} s - The string to check.
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* @returns {boolean} `true` if the string starts with uppercase.
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*/
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function startsWithUpperCase(s) {
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return s[0] !== s[0].toLocaleLowerCase();
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}
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/**
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* Checks whether or not a node is a constructor.
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* @param {ASTNode} node - A function node to check.
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* @returns {boolean} Wehether or not a node is a constructor.
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*/
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function isES5Constructor(node) {
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return (node.id && startsWithUpperCase(node.id.name));
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}
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/**
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* Finds a function node from ancestors of a node.
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* @param {ASTNode} node - A start node to find.
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* @returns {Node|null} A found function node.
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*/
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function getUpperFunction(node) {
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while (node) {
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if (anyFunctionPattern.test(node.type)) {
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return node;
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}
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node = node.parent;
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}
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return null;
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}
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/**
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* Checks whether a given node is a function node or not.
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* The following types are function nodes:
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*
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* - ArrowFunctionExpression
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* - FunctionDeclaration
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* - FunctionExpression
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*
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* @param {ASTNode|null} node - A node to check.
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* @returns {boolean} `true` if the node is a function node.
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*/
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function isFunction(node) {
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return Boolean(node && anyFunctionPattern.test(node.type));
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}
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/**
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* Checks whether a given node is a loop node or not.
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* The following types are loop nodes:
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*
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* - DoWhileStatement
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* - ForInStatement
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* - ForOfStatement
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* - ForStatement
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* - WhileStatement
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*
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* @param {ASTNode|null} node - A node to check.
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* @returns {boolean} `true` if the node is a loop node.
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*/
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function isLoop(node) {
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return Boolean(node && anyLoopPattern.test(node.type));
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}
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/**
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* Checks whether the given node is in a loop or not.
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*
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* @param {ASTNode} node - The node to check.
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* @returns {boolean} `true` if the node is in a loop.
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*/
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function isInLoop(node) {
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while (node && !isFunction(node)) {
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if (isLoop(node)) {
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return true;
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}
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node = node.parent;
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}
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return false;
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}
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/**
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* Checks whether or not a node is `null` or `undefined`.
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* @param {ASTNode} node - A node to check.
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* @returns {boolean} Whether or not the node is a `null` or `undefined`.
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* @public
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*/
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function isNullOrUndefined(node) {
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return (
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module.exports.isNullLiteral(node) ||
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(node.type === "Identifier" && node.name === "undefined") ||
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(node.type === "UnaryExpression" && node.operator === "void")
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);
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}
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/**
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* Checks whether or not a node is callee.
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* @param {ASTNode} node - A node to check.
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* @returns {boolean} Whether or not the node is callee.
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*/
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function isCallee(node) {
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return node.parent.type === "CallExpression" && node.parent.callee === node;
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}
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/**
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* Checks whether or not a node is `Reflect.apply`.
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* @param {ASTNode} node - A node to check.
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* @returns {boolean} Whether or not the node is a `Reflect.apply`.
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*/
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function isReflectApply(node) {
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return (
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node.type === "MemberExpression" &&
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node.object.type === "Identifier" &&
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node.object.name === "Reflect" &&
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node.property.type === "Identifier" &&
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node.property.name === "apply" &&
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node.computed === false
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);
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}
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/**
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* Checks whether or not a node is `Array.from`.
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* @param {ASTNode} node - A node to check.
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* @returns {boolean} Whether or not the node is a `Array.from`.
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*/
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function isArrayFromMethod(node) {
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return (
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node.type === "MemberExpression" &&
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node.object.type === "Identifier" &&
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arrayOrTypedArrayPattern.test(node.object.name) &&
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node.property.type === "Identifier" &&
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node.property.name === "from" &&
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node.computed === false
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);
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}
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/**
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* Checks whether or not a node is a method which has `thisArg`.
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* @param {ASTNode} node - A node to check.
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* @returns {boolean} Whether or not the node is a method which has `thisArg`.
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*/
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function isMethodWhichHasThisArg(node) {
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while (node) {
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if (node.type === "Identifier") {
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return arrayMethodPattern.test(node.name);
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}
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if (node.type === "MemberExpression" && !node.computed) {
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node = node.property;
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continue;
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}
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break;
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}
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return false;
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}
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/**
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* Creates the negate function of the given function.
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* @param {Function} f - The function to negate.
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* @returns {Function} Negated function.
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*/
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function negate(f) {
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return token => !f(token);
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}
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/**
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* Checks whether or not a node has a `@this` tag in its comments.
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* @param {ASTNode} node - A node to check.
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* @param {SourceCode} sourceCode - A SourceCode instance to get comments.
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* @returns {boolean} Whether or not the node has a `@this` tag in its comments.
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*/
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function hasJSDocThisTag(node, sourceCode) {
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const jsdocComment = sourceCode.getJSDocComment(node);
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if (jsdocComment && thisTagPattern.test(jsdocComment.value)) {
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return true;
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}
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// Checks `@this` in its leading comments for callbacks,
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// because callbacks don't have its JSDoc comment.
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// e.g.
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// sinon.test(/* @this sinon.Sandbox */function() { this.spy(); });
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return sourceCode.getCommentsBefore(node).some(comment => thisTagPattern.test(comment.value));
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}
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/**
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* Determines if a node is surrounded by parentheses.
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* @param {SourceCode} sourceCode The ESLint source code object
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* @param {ASTNode} node The node to be checked.
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* @returns {boolean} True if the node is parenthesised.
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* @private
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*/
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function isParenthesised(sourceCode, node) {
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const previousToken = sourceCode.getTokenBefore(node),
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nextToken = sourceCode.getTokenAfter(node);
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return Boolean(previousToken && nextToken) &&
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previousToken.value === "(" && previousToken.range[1] <= node.range[0] &&
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nextToken.value === ")" && nextToken.range[0] >= node.range[1];
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}
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/**
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* Checks if the given token is an arrow token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is an arrow token.
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*/
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function isArrowToken(token) {
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return token.value === "=>" && token.type === "Punctuator";
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}
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/**
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* Checks if the given token is a comma token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is a comma token.
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*/
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function isCommaToken(token) {
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return token.value === "," && token.type === "Punctuator";
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}
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/**
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* Checks if the given token is a semicolon token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is a semicolon token.
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*/
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function isSemicolonToken(token) {
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return token.value === ";" && token.type === "Punctuator";
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}
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/**
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* Checks if the given token is a colon token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is a colon token.
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*/
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function isColonToken(token) {
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return token.value === ":" && token.type === "Punctuator";
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}
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/**
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* Checks if the given token is an opening parenthesis token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is an opening parenthesis token.
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*/
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function isOpeningParenToken(token) {
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return token.value === "(" && token.type === "Punctuator";
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}
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/**
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* Checks if the given token is a closing parenthesis token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is a closing parenthesis token.
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*/
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function isClosingParenToken(token) {
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return token.value === ")" && token.type === "Punctuator";
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}
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/**
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* Checks if the given token is an opening square bracket token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is an opening square bracket token.
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*/
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function isOpeningBracketToken(token) {
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return token.value === "[" && token.type === "Punctuator";
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}
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/**
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* Checks if the given token is a closing square bracket token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is a closing square bracket token.
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*/
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function isClosingBracketToken(token) {
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return token.value === "]" && token.type === "Punctuator";
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}
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/**
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* Checks if the given token is an opening brace token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is an opening brace token.
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*/
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function isOpeningBraceToken(token) {
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return token.value === "{" && token.type === "Punctuator";
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}
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/**
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* Checks if the given token is a closing brace token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is a closing brace token.
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*/
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function isClosingBraceToken(token) {
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return token.value === "}" && token.type === "Punctuator";
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}
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/**
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* Checks if the given token is a comment token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is a comment token.
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*/
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function isCommentToken(token) {
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return token.type === "Line" || token.type === "Block" || token.type === "Shebang";
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}
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/**
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* Checks if the given token is a keyword token or not.
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*
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* @param {Token} token - The token to check.
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* @returns {boolean} `true` if the token is a keyword token.
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*/
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function isKeywordToken(token) {
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return token.type === "Keyword";
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}
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/**
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* Gets the `(` token of the given function node.
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*
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* @param {ASTNode} node - The function node to get.
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* @param {SourceCode} sourceCode - The source code object to get tokens.
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* @returns {Token} `(` token.
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*/
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function getOpeningParenOfParams(node, sourceCode) {
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return node.id
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? sourceCode.getTokenAfter(node.id, isOpeningParenToken)
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: sourceCode.getFirstToken(node, isOpeningParenToken);
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}
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/**
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* Creates a version of the LINEBREAK_MATCHER regex with the global flag.
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* Global regexes are mutable, so this needs to be a function instead of a constant.
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* @returns {RegExp} A global regular expression that matches line terminators
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*/
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function createGlobalLinebreakMatcher() {
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return new RegExp(LINEBREAK_MATCHER.source, "g");
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}
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//------------------------------------------------------------------------------
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// Public Interface
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//------------------------------------------------------------------------------
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module.exports = {
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COMMENTS_IGNORE_PATTERN,
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LINEBREAKS,
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LINEBREAK_MATCHER,
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SHEBANG_MATCHER,
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STATEMENT_LIST_PARENTS,
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/**
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* Determines whether two adjacent tokens are on the same line.
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* @param {Object} left - The left token object.
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* @param {Object} right - The right token object.
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* @returns {boolean} Whether or not the tokens are on the same line.
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* @public
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*/
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isTokenOnSameLine(left, right) {
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return left.loc.end.line === right.loc.start.line;
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},
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isNullOrUndefined,
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isCallee,
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isES5Constructor,
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getUpperFunction,
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isFunction,
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isLoop,
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isInLoop,
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isArrayFromMethod,
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isParenthesised,
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createGlobalLinebreakMatcher,
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isArrowToken,
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isClosingBraceToken,
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isClosingBracketToken,
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isClosingParenToken,
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isColonToken,
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isCommaToken,
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isCommentToken,
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isKeywordToken,
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isNotClosingBraceToken: negate(isClosingBraceToken),
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isNotClosingBracketToken: negate(isClosingBracketToken),
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isNotClosingParenToken: negate(isClosingParenToken),
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isNotColonToken: negate(isColonToken),
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isNotCommaToken: negate(isCommaToken),
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isNotOpeningBraceToken: negate(isOpeningBraceToken),
|
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isNotOpeningBracketToken: negate(isOpeningBracketToken),
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isNotOpeningParenToken: negate(isOpeningParenToken),
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isNotSemicolonToken: negate(isSemicolonToken),
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isOpeningBraceToken,
|
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isOpeningBracketToken,
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isOpeningParenToken,
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isSemicolonToken,
|
|
|
|
/**
|
|
* Checks whether or not a given node is a string literal.
|
|
* @param {ASTNode} node - A node to check.
|
|
* @returns {boolean} `true` if the node is a string literal.
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*/
|
|
isStringLiteral(node) {
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return (
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(node.type === "Literal" && typeof node.value === "string") ||
|
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node.type === "TemplateLiteral"
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);
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},
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|
|
|
/**
|
|
* Checks whether a given node is a breakable statement or not.
|
|
* The node is breakable if the node is one of the following type:
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*
|
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* - DoWhileStatement
|
|
* - ForInStatement
|
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* - ForOfStatement
|
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* - ForStatement
|
|
* - SwitchStatement
|
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* - WhileStatement
|
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*
|
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* @param {ASTNode} node - A node to check.
|
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* @returns {boolean} `true` if the node is breakable.
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*/
|
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isBreakableStatement(node) {
|
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return breakableTypePattern.test(node.type);
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},
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|
|
/**
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|
* Gets the label if the parent node of a given node is a LabeledStatement.
|
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*
|
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* @param {ASTNode} node - A node to get.
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* @returns {string|null} The label or `null`.
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*/
|
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getLabel(node) {
|
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if (node.parent.type === "LabeledStatement") {
|
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return node.parent.label.name;
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}
|
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return null;
|
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},
|
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|
|
/**
|
|
* Gets references which are non initializer and writable.
|
|
* @param {Reference[]} references - An array of references.
|
|
* @returns {Reference[]} An array of only references which are non initializer and writable.
|
|
* @public
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|
*/
|
|
getModifyingReferences(references) {
|
|
return references.filter(isModifyingReference);
|
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},
|
|
|
|
/**
|
|
* Validate that a string passed in is surrounded by the specified character
|
|
* @param {string} val The text to check.
|
|
* @param {string} character The character to see if it's surrounded by.
|
|
* @returns {boolean} True if the text is surrounded by the character, false if not.
|
|
* @private
|
|
*/
|
|
isSurroundedBy(val, character) {
|
|
return val[0] === character && val[val.length - 1] === character;
|
|
},
|
|
|
|
/**
|
|
* Returns whether the provided node is an ESLint directive comment or not
|
|
* @param {Line|Block} node The comment token to be checked
|
|
* @returns {boolean} `true` if the node is an ESLint directive comment
|
|
*/
|
|
isDirectiveComment(node) {
|
|
const comment = node.value.trim();
|
|
|
|
return (
|
|
node.type === "Line" && comment.indexOf("eslint-") === 0 ||
|
|
node.type === "Block" && (
|
|
comment.indexOf("global ") === 0 ||
|
|
comment.indexOf("eslint ") === 0 ||
|
|
comment.indexOf("eslint-") === 0
|
|
)
|
|
);
|
|
},
|
|
|
|
/**
|
|
* Gets the trailing statement of a given node.
|
|
*
|
|
* if (code)
|
|
* consequent;
|
|
*
|
|
* When taking this `IfStatement`, returns `consequent;` statement.
|
|
*
|
|
* @param {ASTNode} A node to get.
|
|
* @returns {ASTNode|null} The trailing statement's node.
|
|
*/
|
|
getTrailingStatement: esutils.ast.trailingStatement,
|
|
|
|
/**
|
|
* Finds the variable by a given name in a given scope and its upper scopes.
|
|
*
|
|
* @param {eslint-scope.Scope} initScope - A scope to start find.
|
|
* @param {string} name - A variable name to find.
|
|
* @returns {eslint-scope.Variable|null} A found variable or `null`.
|
|
*/
|
|
getVariableByName(initScope, name) {
|
|
let scope = initScope;
|
|
|
|
while (scope) {
|
|
const variable = scope.set.get(name);
|
|
|
|
if (variable) {
|
|
return variable;
|
|
}
|
|
|
|
scope = scope.upper;
|
|
}
|
|
|
|
return null;
|
|
},
|
|
|
|
/**
|
|
* Checks whether or not a given function node is the default `this` binding.
|
|
*
|
|
* First, this checks the node:
|
|
*
|
|
* - The function name does not start with uppercase (it's a constructor).
|
|
* - The function does not have a JSDoc comment that has a @this tag.
|
|
*
|
|
* Next, this checks the location of the node.
|
|
* If the location is below, this judges `this` is valid.
|
|
*
|
|
* - The location is not on an object literal.
|
|
* - The location is not assigned to a variable which starts with an uppercase letter.
|
|
* - The location is not on an ES2015 class.
|
|
* - Its `bind`/`call`/`apply` method is not called directly.
|
|
* - The function is not a callback of array methods (such as `.forEach()`) if `thisArg` is given.
|
|
*
|
|
* @param {ASTNode} node - A function node to check.
|
|
* @param {SourceCode} sourceCode - A SourceCode instance to get comments.
|
|
* @returns {boolean} The function node is the default `this` binding.
|
|
*/
|
|
isDefaultThisBinding(node, sourceCode) {
|
|
if (isES5Constructor(node) || hasJSDocThisTag(node, sourceCode)) {
|
|
return false;
|
|
}
|
|
const isAnonymous = node.id === null;
|
|
|
|
while (node) {
|
|
const parent = node.parent;
|
|
|
|
switch (parent.type) {
|
|
|
|
/*
|
|
* Looks up the destination.
|
|
* e.g., obj.foo = nativeFoo || function foo() { ... };
|
|
*/
|
|
case "LogicalExpression":
|
|
case "ConditionalExpression":
|
|
node = parent;
|
|
break;
|
|
|
|
// If the upper function is IIFE, checks the destination of the return value.
|
|
// e.g.
|
|
// obj.foo = (function() {
|
|
// // setup...
|
|
// return function foo() { ... };
|
|
// })();
|
|
case "ReturnStatement": {
|
|
const func = getUpperFunction(parent);
|
|
|
|
if (func === null || !isCallee(func)) {
|
|
return true;
|
|
}
|
|
node = func.parent;
|
|
break;
|
|
}
|
|
|
|
// e.g.
|
|
// var obj = { foo() { ... } };
|
|
// var obj = { foo: function() { ... } };
|
|
// class A { constructor() { ... } }
|
|
// class A { foo() { ... } }
|
|
// class A { get foo() { ... } }
|
|
// class A { set foo() { ... } }
|
|
// class A { static foo() { ... } }
|
|
case "Property":
|
|
case "MethodDefinition":
|
|
return parent.value !== node;
|
|
|
|
// e.g.
|
|
// obj.foo = function foo() { ... };
|
|
// Foo = function() { ... };
|
|
// [obj.foo = function foo() { ... }] = a;
|
|
// [Foo = function() { ... }] = a;
|
|
case "AssignmentExpression":
|
|
case "AssignmentPattern":
|
|
if (parent.right === node) {
|
|
if (parent.left.type === "MemberExpression") {
|
|
return false;
|
|
}
|
|
if (isAnonymous &&
|
|
parent.left.type === "Identifier" &&
|
|
startsWithUpperCase(parent.left.name)
|
|
) {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
|
|
// e.g.
|
|
// var Foo = function() { ... };
|
|
case "VariableDeclarator":
|
|
return !(
|
|
isAnonymous &&
|
|
parent.init === node &&
|
|
parent.id.type === "Identifier" &&
|
|
startsWithUpperCase(parent.id.name)
|
|
);
|
|
|
|
// e.g.
|
|
// var foo = function foo() { ... }.bind(obj);
|
|
// (function foo() { ... }).call(obj);
|
|
// (function foo() { ... }).apply(obj, []);
|
|
case "MemberExpression":
|
|
return (
|
|
parent.object !== node ||
|
|
parent.property.type !== "Identifier" ||
|
|
!bindOrCallOrApplyPattern.test(parent.property.name) ||
|
|
!isCallee(parent) ||
|
|
parent.parent.arguments.length === 0 ||
|
|
isNullOrUndefined(parent.parent.arguments[0])
|
|
);
|
|
|
|
// e.g.
|
|
// Reflect.apply(function() {}, obj, []);
|
|
// Array.from([], function() {}, obj);
|
|
// list.forEach(function() {}, obj);
|
|
case "CallExpression":
|
|
if (isReflectApply(parent.callee)) {
|
|
return (
|
|
parent.arguments.length !== 3 ||
|
|
parent.arguments[0] !== node ||
|
|
isNullOrUndefined(parent.arguments[1])
|
|
);
|
|
}
|
|
if (isArrayFromMethod(parent.callee)) {
|
|
return (
|
|
parent.arguments.length !== 3 ||
|
|
parent.arguments[1] !== node ||
|
|
isNullOrUndefined(parent.arguments[2])
|
|
);
|
|
}
|
|
if (isMethodWhichHasThisArg(parent.callee)) {
|
|
return (
|
|
parent.arguments.length !== 2 ||
|
|
parent.arguments[0] !== node ||
|
|
isNullOrUndefined(parent.arguments[1])
|
|
);
|
|
}
|
|
return true;
|
|
|
|
// Otherwise `this` is default.
|
|
default:
|
|
return true;
|
|
}
|
|
}
|
|
|
|
/* istanbul ignore next */
|
|
return true;
|
|
},
|
|
|
|
/**
|
|
* Get the precedence level based on the node type
|
|
* @param {ASTNode} node node to evaluate
|
|
* @returns {int} precedence level
|
|
* @private
|
|
*/
|
|
getPrecedence(node) {
|
|
switch (node.type) {
|
|
case "SequenceExpression":
|
|
return 0;
|
|
|
|
case "AssignmentExpression":
|
|
case "ArrowFunctionExpression":
|
|
case "YieldExpression":
|
|
return 1;
|
|
|
|
case "ConditionalExpression":
|
|
return 3;
|
|
|
|
case "LogicalExpression":
|
|
switch (node.operator) {
|
|
case "||":
|
|
return 4;
|
|
case "&&":
|
|
return 5;
|
|
|
|
// no default
|
|
}
|
|
|
|
/* falls through */
|
|
|
|
case "BinaryExpression":
|
|
|
|
switch (node.operator) {
|
|
case "|":
|
|
return 6;
|
|
case "^":
|
|
return 7;
|
|
case "&":
|
|
return 8;
|
|
case "==":
|
|
case "!=":
|
|
case "===":
|
|
case "!==":
|
|
return 9;
|
|
case "<":
|
|
case "<=":
|
|
case ">":
|
|
case ">=":
|
|
case "in":
|
|
case "instanceof":
|
|
return 10;
|
|
case "<<":
|
|
case ">>":
|
|
case ">>>":
|
|
return 11;
|
|
case "+":
|
|
case "-":
|
|
return 12;
|
|
case "*":
|
|
case "/":
|
|
case "%":
|
|
return 13;
|
|
case "**":
|
|
return 15;
|
|
|
|
// no default
|
|
}
|
|
|
|
/* falls through */
|
|
|
|
case "UnaryExpression":
|
|
case "AwaitExpression":
|
|
return 16;
|
|
|
|
case "UpdateExpression":
|
|
return 17;
|
|
|
|
case "CallExpression":
|
|
|
|
// IIFE is allowed to have parens in any position (#655)
|
|
if (node.callee.type === "FunctionExpression") {
|
|
return -1;
|
|
}
|
|
return 18;
|
|
|
|
case "NewExpression":
|
|
return 19;
|
|
|
|
// no default
|
|
}
|
|
return 20;
|
|
},
|
|
|
|
/**
|
|
* Checks whether the given node is an empty block node or not.
|
|
*
|
|
* @param {ASTNode|null} node - The node to check.
|
|
* @returns {boolean} `true` if the node is an empty block.
|
|
*/
|
|
isEmptyBlock(node) {
|
|
return Boolean(node && node.type === "BlockStatement" && node.body.length === 0);
|
|
},
|
|
|
|
/**
|
|
* Checks whether the given node is an empty function node or not.
|
|
*
|
|
* @param {ASTNode|null} node - The node to check.
|
|
* @returns {boolean} `true` if the node is an empty function.
|
|
*/
|
|
isEmptyFunction(node) {
|
|
return isFunction(node) && module.exports.isEmptyBlock(node.body);
|
|
},
|
|
|
|
/**
|
|
* Gets the property name of a given node.
|
|
* The node can be a MemberExpression, a Property, or a MethodDefinition.
|
|
*
|
|
* If the name is dynamic, this returns `null`.
|
|
*
|
|
* For examples:
|
|
*
|
|
* a.b // => "b"
|
|
* a["b"] // => "b"
|
|
* a['b'] // => "b"
|
|
* a[`b`] // => "b"
|
|
* a[100] // => "100"
|
|
* a[b] // => null
|
|
* a["a" + "b"] // => null
|
|
* a[tag`b`] // => null
|
|
* a[`${b}`] // => null
|
|
*
|
|
* let a = {b: 1} // => "b"
|
|
* let a = {["b"]: 1} // => "b"
|
|
* let a = {['b']: 1} // => "b"
|
|
* let a = {[`b`]: 1} // => "b"
|
|
* let a = {[100]: 1} // => "100"
|
|
* let a = {[b]: 1} // => null
|
|
* let a = {["a" + "b"]: 1} // => null
|
|
* let a = {[tag`b`]: 1} // => null
|
|
* let a = {[`${b}`]: 1} // => null
|
|
*
|
|
* @param {ASTNode} node - The node to get.
|
|
* @returns {string|null} The property name if static. Otherwise, null.
|
|
*/
|
|
getStaticPropertyName(node) {
|
|
let prop;
|
|
|
|
switch (node && node.type) {
|
|
case "Property":
|
|
case "MethodDefinition":
|
|
prop = node.key;
|
|
break;
|
|
|
|
case "MemberExpression":
|
|
prop = node.property;
|
|
break;
|
|
|
|
// no default
|
|
}
|
|
|
|
switch (prop && prop.type) {
|
|
case "Literal":
|
|
return String(prop.value);
|
|
|
|
case "TemplateLiteral":
|
|
if (prop.expressions.length === 0 && prop.quasis.length === 1) {
|
|
return prop.quasis[0].value.cooked;
|
|
}
|
|
break;
|
|
|
|
case "Identifier":
|
|
if (!node.computed) {
|
|
return prop.name;
|
|
}
|
|
break;
|
|
|
|
// no default
|
|
}
|
|
|
|
return null;
|
|
},
|
|
|
|
/**
|
|
* Get directives from directive prologue of a Program or Function node.
|
|
* @param {ASTNode} node - The node to check.
|
|
* @returns {ASTNode[]} The directives found in the directive prologue.
|
|
*/
|
|
getDirectivePrologue(node) {
|
|
const directives = [];
|
|
|
|
// Directive prologues only occur at the top of files or functions.
|
|
if (
|
|
node.type === "Program" ||
|
|
node.type === "FunctionDeclaration" ||
|
|
node.type === "FunctionExpression" ||
|
|
|
|
// Do not check arrow functions with implicit return.
|
|
// `() => "use strict";` returns the string `"use strict"`.
|
|
(node.type === "ArrowFunctionExpression" && node.body.type === "BlockStatement")
|
|
) {
|
|
const statements = node.type === "Program" ? node.body : node.body.body;
|
|
|
|
for (const statement of statements) {
|
|
if (
|
|
statement.type === "ExpressionStatement" &&
|
|
statement.expression.type === "Literal"
|
|
) {
|
|
directives.push(statement);
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return directives;
|
|
},
|
|
|
|
|
|
/**
|
|
* Determines whether this node is a decimal integer literal. If a node is a decimal integer literal, a dot added
|
|
after the node will be parsed as a decimal point, rather than a property-access dot.
|
|
* @param {ASTNode} node - The node to check.
|
|
* @returns {boolean} `true` if this node is a decimal integer.
|
|
* @example
|
|
*
|
|
* 5 // true
|
|
* 5. // false
|
|
* 5.0 // false
|
|
* 05 // false
|
|
* 0x5 // false
|
|
* 0b101 // false
|
|
* 0o5 // false
|
|
* 5e0 // false
|
|
* '5' // false
|
|
*/
|
|
isDecimalInteger(node) {
|
|
return node.type === "Literal" && typeof node.value === "number" && /^(0|[1-9]\d*)$/.test(node.raw);
|
|
},
|
|
|
|
/**
|
|
* Gets the name and kind of the given function node.
|
|
*
|
|
* - `function foo() {}` .................... `function 'foo'`
|
|
* - `(function foo() {})` .................. `function 'foo'`
|
|
* - `(function() {})` ...................... `function`
|
|
* - `function* foo() {}` ................... `generator function 'foo'`
|
|
* - `(function* foo() {})` ................. `generator function 'foo'`
|
|
* - `(function*() {})` ..................... `generator function`
|
|
* - `() => {}` ............................. `arrow function`
|
|
* - `async () => {}` ....................... `async arrow function`
|
|
* - `({ foo: function foo() {} })` ......... `method 'foo'`
|
|
* - `({ foo: function() {} })` ............. `method 'foo'`
|
|
* - `({ ['foo']: function() {} })` ......... `method 'foo'`
|
|
* - `({ [foo]: function() {} })` ........... `method`
|
|
* - `({ foo() {} })` ....................... `method 'foo'`
|
|
* - `({ foo: function* foo() {} })` ........ `generator method 'foo'`
|
|
* - `({ foo: function*() {} })` ............ `generator method 'foo'`
|
|
* - `({ ['foo']: function*() {} })` ........ `generator method 'foo'`
|
|
* - `({ [foo]: function*() {} })` .......... `generator method`
|
|
* - `({ *foo() {} })` ...................... `generator method 'foo'`
|
|
* - `({ foo: async function foo() {} })` ... `async method 'foo'`
|
|
* - `({ foo: async function() {} })` ....... `async method 'foo'`
|
|
* - `({ ['foo']: async function() {} })` ... `async method 'foo'`
|
|
* - `({ [foo]: async function() {} })` ..... `async method`
|
|
* - `({ async foo() {} })` ................. `async method 'foo'`
|
|
* - `({ get foo() {} })` ................... `getter 'foo'`
|
|
* - `({ set foo(a) {} })` .................. `setter 'foo'`
|
|
* - `class A { constructor() {} }` ......... `constructor`
|
|
* - `class A { foo() {} }` ................. `method 'foo'`
|
|
* - `class A { *foo() {} }` ................ `generator method 'foo'`
|
|
* - `class A { async foo() {} }` ........... `async method 'foo'`
|
|
* - `class A { ['foo']() {} }` ............. `method 'foo'`
|
|
* - `class A { *['foo']() {} }` ............ `generator method 'foo'`
|
|
* - `class A { async ['foo']() {} }` ....... `async method 'foo'`
|
|
* - `class A { [foo]() {} }` ............... `method`
|
|
* - `class A { *[foo]() {} }` .............. `generator method`
|
|
* - `class A { async [foo]() {} }` ......... `async method`
|
|
* - `class A { get foo() {} }` ............. `getter 'foo'`
|
|
* - `class A { set foo(a) {} }` ............ `setter 'foo'`
|
|
* - `class A { static foo() {} }` .......... `static method 'foo'`
|
|
* - `class A { static *foo() {} }` ......... `static generator method 'foo'`
|
|
* - `class A { static async foo() {} }` .... `static async method 'foo'`
|
|
* - `class A { static get foo() {} }` ...... `static getter 'foo'`
|
|
* - `class A { static set foo(a) {} }` ..... `static setter 'foo'`
|
|
*
|
|
* @param {ASTNode} node - The function node to get.
|
|
* @returns {string} The name and kind of the function node.
|
|
*/
|
|
getFunctionNameWithKind(node) {
|
|
const parent = node.parent;
|
|
const tokens = [];
|
|
|
|
if (parent.type === "MethodDefinition" && parent.static) {
|
|
tokens.push("static");
|
|
}
|
|
if (node.async) {
|
|
tokens.push("async");
|
|
}
|
|
if (node.generator) {
|
|
tokens.push("generator");
|
|
}
|
|
|
|
if (node.type === "ArrowFunctionExpression") {
|
|
tokens.push("arrow", "function");
|
|
} else if (parent.type === "Property" || parent.type === "MethodDefinition") {
|
|
if (parent.kind === "constructor") {
|
|
return "constructor";
|
|
} else if (parent.kind === "get") {
|
|
tokens.push("getter");
|
|
} else if (parent.kind === "set") {
|
|
tokens.push("setter");
|
|
} else {
|
|
tokens.push("method");
|
|
}
|
|
} else {
|
|
tokens.push("function");
|
|
}
|
|
|
|
if (node.id) {
|
|
tokens.push(`'${node.id.name}'`);
|
|
} else {
|
|
const name = module.exports.getStaticPropertyName(parent);
|
|
|
|
if (name) {
|
|
tokens.push(`'${name}'`);
|
|
}
|
|
}
|
|
|
|
return tokens.join(" ");
|
|
},
|
|
|
|
/**
|
|
* Gets the location of the given function node for reporting.
|
|
*
|
|
* - `function foo() {}`
|
|
* ^^^^^^^^^^^^
|
|
* - `(function foo() {})`
|
|
* ^^^^^^^^^^^^
|
|
* - `(function() {})`
|
|
* ^^^^^^^^
|
|
* - `function* foo() {}`
|
|
* ^^^^^^^^^^^^^
|
|
* - `(function* foo() {})`
|
|
* ^^^^^^^^^^^^^
|
|
* - `(function*() {})`
|
|
* ^^^^^^^^^
|
|
* - `() => {}`
|
|
* ^^
|
|
* - `async () => {}`
|
|
* ^^
|
|
* - `({ foo: function foo() {} })`
|
|
* ^^^^^^^^^^^^^^^^^
|
|
* - `({ foo: function() {} })`
|
|
* ^^^^^^^^^^^^^
|
|
* - `({ ['foo']: function() {} })`
|
|
* ^^^^^^^^^^^^^^^^^
|
|
* - `({ [foo]: function() {} })`
|
|
* ^^^^^^^^^^^^^^^
|
|
* - `({ foo() {} })`
|
|
* ^^^
|
|
* - `({ foo: function* foo() {} })`
|
|
* ^^^^^^^^^^^^^^^^^^
|
|
* - `({ foo: function*() {} })`
|
|
* ^^^^^^^^^^^^^^
|
|
* - `({ ['foo']: function*() {} })`
|
|
* ^^^^^^^^^^^^^^^^^^
|
|
* - `({ [foo]: function*() {} })`
|
|
* ^^^^^^^^^^^^^^^^
|
|
* - `({ *foo() {} })`
|
|
* ^^^^
|
|
* - `({ foo: async function foo() {} })`
|
|
* ^^^^^^^^^^^^^^^^^^^^^^^
|
|
* - `({ foo: async function() {} })`
|
|
* ^^^^^^^^^^^^^^^^^^^
|
|
* - `({ ['foo']: async function() {} })`
|
|
* ^^^^^^^^^^^^^^^^^^^^^^^
|
|
* - `({ [foo]: async function() {} })`
|
|
* ^^^^^^^^^^^^^^^^^^^^^
|
|
* - `({ async foo() {} })`
|
|
* ^^^^^^^^^
|
|
* - `({ get foo() {} })`
|
|
* ^^^^^^^
|
|
* - `({ set foo(a) {} })`
|
|
* ^^^^^^^
|
|
* - `class A { constructor() {} }`
|
|
* ^^^^^^^^^^^
|
|
* - `class A { foo() {} }`
|
|
* ^^^
|
|
* - `class A { *foo() {} }`
|
|
* ^^^^
|
|
* - `class A { async foo() {} }`
|
|
* ^^^^^^^^^
|
|
* - `class A { ['foo']() {} }`
|
|
* ^^^^^^^
|
|
* - `class A { *['foo']() {} }`
|
|
* ^^^^^^^^
|
|
* - `class A { async ['foo']() {} }`
|
|
* ^^^^^^^^^^^^^
|
|
* - `class A { [foo]() {} }`
|
|
* ^^^^^
|
|
* - `class A { *[foo]() {} }`
|
|
* ^^^^^^
|
|
* - `class A { async [foo]() {} }`
|
|
* ^^^^^^^^^^^
|
|
* - `class A { get foo() {} }`
|
|
* ^^^^^^^
|
|
* - `class A { set foo(a) {} }`
|
|
* ^^^^^^^
|
|
* - `class A { static foo() {} }`
|
|
* ^^^^^^^^^^
|
|
* - `class A { static *foo() {} }`
|
|
* ^^^^^^^^^^^
|
|
* - `class A { static async foo() {} }`
|
|
* ^^^^^^^^^^^^^^^^
|
|
* - `class A { static get foo() {} }`
|
|
* ^^^^^^^^^^^^^^
|
|
* - `class A { static set foo(a) {} }`
|
|
* ^^^^^^^^^^^^^^
|
|
*
|
|
* @param {ASTNode} node - The function node to get.
|
|
* @param {SourceCode} sourceCode - The source code object to get tokens.
|
|
* @returns {string} The location of the function node for reporting.
|
|
*/
|
|
getFunctionHeadLoc(node, sourceCode) {
|
|
const parent = node.parent;
|
|
let start = null;
|
|
let end = null;
|
|
|
|
if (node.type === "ArrowFunctionExpression") {
|
|
const arrowToken = sourceCode.getTokenBefore(node.body, isArrowToken);
|
|
|
|
start = arrowToken.loc.start;
|
|
end = arrowToken.loc.end;
|
|
} else if (parent.type === "Property" || parent.type === "MethodDefinition") {
|
|
start = parent.loc.start;
|
|
end = getOpeningParenOfParams(node, sourceCode).loc.start;
|
|
} else {
|
|
start = node.loc.start;
|
|
end = getOpeningParenOfParams(node, sourceCode).loc.start;
|
|
}
|
|
|
|
return {
|
|
start: Object.assign({}, start),
|
|
end: Object.assign({}, end)
|
|
};
|
|
},
|
|
|
|
/**
|
|
* Gets the parenthesized text of a node. This is similar to sourceCode.getText(node), but it also includes any parentheses
|
|
* surrounding the node.
|
|
* @param {SourceCode} sourceCode The source code object
|
|
* @param {ASTNode} node An expression node
|
|
* @returns {string} The text representing the node, with all surrounding parentheses included
|
|
*/
|
|
getParenthesisedText(sourceCode, node) {
|
|
let leftToken = sourceCode.getFirstToken(node);
|
|
let rightToken = sourceCode.getLastToken(node);
|
|
|
|
while (
|
|
sourceCode.getTokenBefore(leftToken) &&
|
|
sourceCode.getTokenBefore(leftToken).type === "Punctuator" &&
|
|
sourceCode.getTokenBefore(leftToken).value === "(" &&
|
|
sourceCode.getTokenAfter(rightToken) &&
|
|
sourceCode.getTokenAfter(rightToken).type === "Punctuator" &&
|
|
sourceCode.getTokenAfter(rightToken).value === ")"
|
|
) {
|
|
leftToken = sourceCode.getTokenBefore(leftToken);
|
|
rightToken = sourceCode.getTokenAfter(rightToken);
|
|
}
|
|
|
|
return sourceCode.getText().slice(leftToken.range[0], rightToken.range[1]);
|
|
},
|
|
|
|
/*
|
|
* Determine if a node has a possiblity to be an Error object
|
|
* @param {ASTNode} node ASTNode to check
|
|
* @returns {boolean} True if there is a chance it contains an Error obj
|
|
*/
|
|
couldBeError(node) {
|
|
switch (node.type) {
|
|
case "Identifier":
|
|
case "CallExpression":
|
|
case "NewExpression":
|
|
case "MemberExpression":
|
|
case "TaggedTemplateExpression":
|
|
case "YieldExpression":
|
|
case "AwaitExpression":
|
|
return true; // possibly an error object.
|
|
|
|
case "AssignmentExpression":
|
|
return module.exports.couldBeError(node.right);
|
|
|
|
case "SequenceExpression": {
|
|
const exprs = node.expressions;
|
|
|
|
return exprs.length !== 0 && module.exports.couldBeError(exprs[exprs.length - 1]);
|
|
}
|
|
|
|
case "LogicalExpression":
|
|
return module.exports.couldBeError(node.left) || module.exports.couldBeError(node.right);
|
|
|
|
case "ConditionalExpression":
|
|
return module.exports.couldBeError(node.consequent) || module.exports.couldBeError(node.alternate);
|
|
|
|
default:
|
|
return false;
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Determines whether the given node is a `null` literal.
|
|
* @param {ASTNode} node The node to check
|
|
* @returns {boolean} `true` if the node is a `null` literal
|
|
*/
|
|
isNullLiteral(node) {
|
|
|
|
/*
|
|
* Checking `node.value === null` does not guarantee that a literal is a null literal.
|
|
* When parsing values that cannot be represented in the current environment (e.g. unicode
|
|
* regexes in Node 4), `node.value` is set to `null` because it wouldn't be possible to
|
|
* set `node.value` to a unicode regex. To make sure a literal is actually `null`, check
|
|
* `node.regex` instead. Also see: https://github.com/eslint/eslint/issues/8020
|
|
*/
|
|
return node.type === "Literal" && node.value === null && !node.regex;
|
|
},
|
|
|
|
/**
|
|
* Determines whether two tokens can safely be placed next to each other without merging into a single token
|
|
* @param {Token|string} leftValue The left token. If this is a string, it will be tokenized and the last token will be used.
|
|
* @param {Token|string} rightValue The right token. If this is a string, it will be tokenized and the first token will be used.
|
|
* @returns {boolean} If the tokens cannot be safely placed next to each other, returns `false`. If the tokens can be placed
|
|
* next to each other, behavior is undefined (although it should return `true` in most cases).
|
|
*/
|
|
canTokensBeAdjacent(leftValue, rightValue) {
|
|
let leftToken;
|
|
|
|
if (typeof leftValue === "string") {
|
|
const leftTokens = espree.tokenize(leftValue, { ecmaVersion: 2015 });
|
|
|
|
leftToken = leftTokens[leftTokens.length - 1];
|
|
} else {
|
|
leftToken = leftValue;
|
|
}
|
|
|
|
const rightToken = typeof rightValue === "string" ? espree.tokenize(rightValue, { ecmaVersion: 2015 })[0] : rightValue;
|
|
|
|
if (leftToken.type === "Punctuator" || rightToken.type === "Punctuator") {
|
|
if (leftToken.type === "Punctuator" && rightToken.type === "Punctuator") {
|
|
const PLUS_TOKENS = new Set(["+", "++"]);
|
|
const MINUS_TOKENS = new Set(["-", "--"]);
|
|
|
|
return !(
|
|
PLUS_TOKENS.has(leftToken.value) && PLUS_TOKENS.has(rightToken.value) ||
|
|
MINUS_TOKENS.has(leftToken.value) && MINUS_TOKENS.has(rightToken.value)
|
|
);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
if (
|
|
leftToken.type === "String" || rightToken.type === "String" ||
|
|
leftToken.type === "Template" || rightToken.type === "Template"
|
|
) {
|
|
return true;
|
|
}
|
|
|
|
if (leftToken.type !== "Numeric" && rightToken.type === "Numeric" && rightToken.value.startsWith(".")) {
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
};
|