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2282 lines
79 KiB
2282 lines
79 KiB
/**
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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 { KEYS: eslintVisitorKeys } = require("eslint-visitor-keys");
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const esutils = require("esutils");
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const espree = require("espree");
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const escapeRegExp = require("escape-string-regexp");
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const {
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breakableTypePattern,
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createGlobalLinebreakMatcher,
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lineBreakPattern,
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shebangPattern
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} = require("../../shared/ast-utils");
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//------------------------------------------------------------------------------
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// Helpers
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//------------------------------------------------------------------------------
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const anyFunctionPattern = /^(?:Function(?:Declaration|Expression)|ArrowFunctionExpression)$/u;
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const anyLoopPattern = /^(?:DoWhile|For|ForIn|ForOf|While)Statement$/u;
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const arrayMethodWithThisArgPattern = /^(?:every|filter|find(?:Last)?(?:Index)?|flatMap|forEach|map|some)$/u;
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const arrayOrTypedArrayPattern = /Array$/u;
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const bindOrCallOrApplyPattern = /^(?:bind|call|apply)$/u;
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const thisTagPattern = /^[\s*]*@this/mu;
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const COMMENTS_IGNORE_PATTERN = /^\s*(?:eslint|jshint\s+|jslint\s+|istanbul\s+|globals?\s+|exported\s+|jscs)/u;
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const ESLINT_DIRECTIVE_PATTERN = /^(?:eslint[- ]|(?:globals?|exported) )/u;
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const LINEBREAKS = new Set(["\r\n", "\r", "\n", "\u2028", "\u2029"]);
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// A set of node types that can contain a list of statements
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const STATEMENT_LIST_PARENTS = new Set(["Program", "BlockStatement", "StaticBlock", "SwitchCase"]);
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const DECIMAL_INTEGER_PATTERN = /^(?:0|0[0-7]*[89]\d*|[1-9](?:_?\d)*)$/u;
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// Tests the presence of at least one LegacyOctalEscapeSequence or NonOctalDecimalEscapeSequence in a raw string
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const OCTAL_OR_NON_OCTAL_DECIMAL_ESCAPE_PATTERN = /^(?:[^\\]|\\.)*\\(?:[1-9]|0[0-9])/su;
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const LOGICAL_ASSIGNMENT_OPERATORS = new Set(["&&=", "||=", "??="]);
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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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* @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} Whether 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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for (let currentNode = node; currentNode; currentNode = currentNode.parent) {
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if (anyFunctionPattern.test(currentNode.type)) {
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return currentNode;
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}
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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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* @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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* @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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* @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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for (let currentNode = node; currentNode && !isFunction(currentNode); currentNode = currentNode.parent) {
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if (isLoop(currentNode)) {
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return true;
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}
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}
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return false;
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}
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/**
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* Determines whether the given node is a `null` literal.
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* @param {ASTNode} node The node to check
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* @returns {boolean} `true` if the node is a `null` literal
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*/
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function isNullLiteral(node) {
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/*
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* Checking `node.value === null` does not guarantee that a literal is a null literal.
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* When parsing values that cannot be represented in the current environment (e.g. unicode
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* regexes in Node 4), `node.value` is set to `null` because it wouldn't be possible to
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* set `node.value` to a unicode regex. To make sure a literal is actually `null`, check
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* `node.regex` instead. Also see: https://github.com/eslint/eslint/issues/8020
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*/
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return node.type === "Literal" && node.value === null && !node.regex && !node.bigint;
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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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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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* Returns the result of the string conversion applied to the evaluated value of the given expression node,
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* if it can be determined statically.
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*
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* This function returns a `string` value for all `Literal` nodes and simple `TemplateLiteral` nodes only.
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* In all other cases, this function returns `null`.
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* @param {ASTNode} node Expression node.
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* @returns {string|null} String value if it can be determined. Otherwise, `null`.
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*/
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function getStaticStringValue(node) {
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switch (node.type) {
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case "Literal":
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if (node.value === null) {
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if (isNullLiteral(node)) {
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return String(node.value); // "null"
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}
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if (node.regex) {
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return `/${node.regex.pattern}/${node.regex.flags}`;
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}
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if (node.bigint) {
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return node.bigint;
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}
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// Otherwise, this is an unknown literal. The function will return null.
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} else {
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return String(node.value);
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}
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break;
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case "TemplateLiteral":
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if (node.expressions.length === 0 && node.quasis.length === 1) {
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return node.quasis[0].value.cooked;
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}
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break;
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// no default
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}
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return null;
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}
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/**
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* Gets the property name of a given node.
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* The node can be a MemberExpression, a Property, or a MethodDefinition.
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*
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* If the name is dynamic, this returns `null`.
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*
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* For examples:
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*
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* a.b // => "b"
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* a["b"] // => "b"
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* a['b'] // => "b"
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* a[`b`] // => "b"
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* a[100] // => "100"
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* a[b] // => null
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* a["a" + "b"] // => null
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* a[tag`b`] // => null
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* a[`${b}`] // => null
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*
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* let a = {b: 1} // => "b"
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* let a = {["b"]: 1} // => "b"
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* let a = {['b']: 1} // => "b"
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* let a = {[`b`]: 1} // => "b"
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* let a = {[100]: 1} // => "100"
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* let a = {[b]: 1} // => null
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* let a = {["a" + "b"]: 1} // => null
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* let a = {[tag`b`]: 1} // => null
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* let a = {[`${b}`]: 1} // => null
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* @param {ASTNode} node The node to get.
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* @returns {string|null} The property name if static. Otherwise, null.
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*/
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function getStaticPropertyName(node) {
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let prop;
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switch (node && node.type) {
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case "ChainExpression":
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return getStaticPropertyName(node.expression);
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case "Property":
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case "PropertyDefinition":
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case "MethodDefinition":
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prop = node.key;
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break;
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case "MemberExpression":
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prop = node.property;
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break;
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// no default
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}
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if (prop) {
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if (prop.type === "Identifier" && !node.computed) {
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return prop.name;
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}
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return getStaticStringValue(prop);
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}
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return null;
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}
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/**
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* Retrieve `ChainExpression#expression` value if the given node a `ChainExpression` node. Otherwise, pass through it.
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* @param {ASTNode} node The node to address.
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* @returns {ASTNode} The `ChainExpression#expression` value if the node is a `ChainExpression` node. Otherwise, the node.
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*/
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function skipChainExpression(node) {
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return node && node.type === "ChainExpression" ? node.expression : node;
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}
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/**
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* Check if the `actual` is an expected value.
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* @param {string} actual The string value to check.
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* @param {string | RegExp} expected The expected string value or pattern.
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* @returns {boolean} `true` if the `actual` is an expected value.
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*/
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function checkText(actual, expected) {
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return typeof expected === "string"
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? actual === expected
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: expected.test(actual);
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}
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/**
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* Check if a given node is an Identifier node with a given name.
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* @param {ASTNode} node The node to check.
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* @param {string | RegExp} name The expected name or the expected pattern of the object name.
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* @returns {boolean} `true` if the node is an Identifier node with the name.
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*/
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function isSpecificId(node, name) {
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return node.type === "Identifier" && checkText(node.name, name);
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}
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/**
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* Check if a given node is member access with a given object name and property name pair.
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* This is regardless of optional or not.
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* @param {ASTNode} node The node to check.
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* @param {string | RegExp | null} objectName The expected name or the expected pattern of the object name. If this is nullish, this method doesn't check object.
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* @param {string | RegExp | null} propertyName The expected name or the expected pattern of the property name. If this is nullish, this method doesn't check property.
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* @returns {boolean} `true` if the node is member access with the object name and property name pair.
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* The node is a `MemberExpression` or `ChainExpression`.
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*/
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function isSpecificMemberAccess(node, objectName, propertyName) {
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const checkNode = skipChainExpression(node);
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if (checkNode.type !== "MemberExpression") {
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return false;
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}
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if (objectName && !isSpecificId(checkNode.object, objectName)) {
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return false;
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}
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if (propertyName) {
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const actualPropertyName = getStaticPropertyName(checkNode);
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if (typeof actualPropertyName !== "string" || !checkText(actualPropertyName, propertyName)) {
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return false;
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}
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}
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return true;
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}
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/**
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* Check if two literal nodes are the same value.
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* @param {ASTNode} left The Literal node to compare.
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* @param {ASTNode} right The other Literal node to compare.
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* @returns {boolean} `true` if the two literal nodes are the same value.
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*/
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function equalLiteralValue(left, right) {
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// RegExp literal.
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if (left.regex || right.regex) {
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return Boolean(
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left.regex &&
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right.regex &&
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left.regex.pattern === right.regex.pattern &&
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left.regex.flags === right.regex.flags
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);
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}
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// BigInt literal.
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if (left.bigint || right.bigint) {
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return left.bigint === right.bigint;
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}
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return left.value === right.value;
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}
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/**
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* Check if two expressions reference the same value. For example:
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* a = a
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* a.b = a.b
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* a[0] = a[0]
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* a['b'] = a['b']
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* @param {ASTNode} left The left side of the comparison.
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* @param {ASTNode} right The right side of the comparison.
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* @param {boolean} [disableStaticComputedKey] Don't address `a.b` and `a["b"]` are the same if `true`. For backward compatibility.
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* @returns {boolean} `true` if both sides match and reference the same value.
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*/
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function isSameReference(left, right, disableStaticComputedKey = false) {
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if (left.type !== right.type) {
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// Handle `a.b` and `a?.b` are samely.
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if (left.type === "ChainExpression") {
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return isSameReference(left.expression, right, disableStaticComputedKey);
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}
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if (right.type === "ChainExpression") {
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return isSameReference(left, right.expression, disableStaticComputedKey);
|
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}
|
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return false;
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}
|
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|
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switch (left.type) {
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case "Super":
|
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case "ThisExpression":
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return true;
|
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|
|
case "Identifier":
|
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case "PrivateIdentifier":
|
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return left.name === right.name;
|
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case "Literal":
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return equalLiteralValue(left, right);
|
|
|
|
case "ChainExpression":
|
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return isSameReference(left.expression, right.expression, disableStaticComputedKey);
|
|
|
|
case "MemberExpression": {
|
|
if (!disableStaticComputedKey) {
|
|
const nameA = getStaticPropertyName(left);
|
|
|
|
// x.y = x["y"]
|
|
if (nameA !== null) {
|
|
return (
|
|
isSameReference(left.object, right.object, disableStaticComputedKey) &&
|
|
nameA === getStaticPropertyName(right)
|
|
);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* x[0] = x[0]
|
|
* x[y] = x[y]
|
|
* x.y = x.y
|
|
*/
|
|
return (
|
|
left.computed === right.computed &&
|
|
isSameReference(left.object, right.object, disableStaticComputedKey) &&
|
|
isSameReference(left.property, right.property, disableStaticComputedKey)
|
|
);
|
|
}
|
|
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Checks whether or not a node is `Reflect.apply`.
|
|
* @param {ASTNode} node A node to check.
|
|
* @returns {boolean} Whether or not the node is a `Reflect.apply`.
|
|
*/
|
|
function isReflectApply(node) {
|
|
return isSpecificMemberAccess(node, "Reflect", "apply");
|
|
}
|
|
|
|
/**
|
|
* Checks whether or not a node is `Array.from`.
|
|
* @param {ASTNode} node A node to check.
|
|
* @returns {boolean} Whether or not the node is a `Array.from`.
|
|
*/
|
|
function isArrayFromMethod(node) {
|
|
return isSpecificMemberAccess(node, arrayOrTypedArrayPattern, "from");
|
|
}
|
|
|
|
/**
|
|
* Checks whether or not a node is a method which expects a function as a first argument, and `thisArg` as a second argument.
|
|
* @param {ASTNode} node A node to check.
|
|
* @returns {boolean} Whether or not the node is a method which expects a function as a first argument, and `thisArg` as a second argument.
|
|
*/
|
|
function isMethodWhichHasThisArg(node) {
|
|
return isSpecificMemberAccess(node, null, arrayMethodWithThisArgPattern);
|
|
}
|
|
|
|
/**
|
|
* Creates the negate function of the given function.
|
|
* @param {Function} f The function to negate.
|
|
* @returns {Function} Negated function.
|
|
*/
|
|
function negate(f) {
|
|
return token => !f(token);
|
|
}
|
|
|
|
/**
|
|
* Checks whether or not a node has a `@this` tag in its comments.
|
|
* @param {ASTNode} node A node to check.
|
|
* @param {SourceCode} sourceCode A SourceCode instance to get comments.
|
|
* @returns {boolean} Whether or not the node has a `@this` tag in its comments.
|
|
*/
|
|
function hasJSDocThisTag(node, sourceCode) {
|
|
const jsdocComment = sourceCode.getJSDocComment(node);
|
|
|
|
if (jsdocComment && thisTagPattern.test(jsdocComment.value)) {
|
|
return true;
|
|
}
|
|
|
|
// Checks `@this` in its leading comments for callbacks,
|
|
// because callbacks don't have its JSDoc comment.
|
|
// e.g.
|
|
// sinon.test(/* @this sinon.Sandbox */function() { this.spy(); });
|
|
return sourceCode.getCommentsBefore(node).some(comment => thisTagPattern.test(comment.value));
|
|
}
|
|
|
|
/**
|
|
* Determines if a node is surrounded by parentheses.
|
|
* @param {SourceCode} sourceCode The ESLint source code object
|
|
* @param {ASTNode} node The node to be checked.
|
|
* @returns {boolean} True if the node is parenthesised.
|
|
* @private
|
|
*/
|
|
function isParenthesised(sourceCode, node) {
|
|
const previousToken = sourceCode.getTokenBefore(node),
|
|
nextToken = sourceCode.getTokenAfter(node);
|
|
|
|
return Boolean(previousToken && nextToken) &&
|
|
previousToken.value === "(" && previousToken.range[1] <= node.range[0] &&
|
|
nextToken.value === ")" && nextToken.range[0] >= node.range[1];
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a `=` token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a `=` token.
|
|
*/
|
|
function isEqToken(token) {
|
|
return token.value === "=" && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is an arrow token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is an arrow token.
|
|
*/
|
|
function isArrowToken(token) {
|
|
return token.value === "=>" && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a comma token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a comma token.
|
|
*/
|
|
function isCommaToken(token) {
|
|
return token.value === "," && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a dot token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a dot token.
|
|
*/
|
|
function isDotToken(token) {
|
|
return token.value === "." && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a `?.` token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a `?.` token.
|
|
*/
|
|
function isQuestionDotToken(token) {
|
|
return token.value === "?." && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a semicolon token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a semicolon token.
|
|
*/
|
|
function isSemicolonToken(token) {
|
|
return token.value === ";" && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a colon token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a colon token.
|
|
*/
|
|
function isColonToken(token) {
|
|
return token.value === ":" && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is an opening parenthesis token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is an opening parenthesis token.
|
|
*/
|
|
function isOpeningParenToken(token) {
|
|
return token.value === "(" && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a closing parenthesis token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a closing parenthesis token.
|
|
*/
|
|
function isClosingParenToken(token) {
|
|
return token.value === ")" && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is an opening square bracket token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is an opening square bracket token.
|
|
*/
|
|
function isOpeningBracketToken(token) {
|
|
return token.value === "[" && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a closing square bracket token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a closing square bracket token.
|
|
*/
|
|
function isClosingBracketToken(token) {
|
|
return token.value === "]" && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is an opening brace token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is an opening brace token.
|
|
*/
|
|
function isOpeningBraceToken(token) {
|
|
return token.value === "{" && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a closing brace token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a closing brace token.
|
|
*/
|
|
function isClosingBraceToken(token) {
|
|
return token.value === "}" && token.type === "Punctuator";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a comment token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a comment token.
|
|
*/
|
|
function isCommentToken(token) {
|
|
return token.type === "Line" || token.type === "Block" || token.type === "Shebang";
|
|
}
|
|
|
|
/**
|
|
* Checks if the given token is a keyword token or not.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if the token is a keyword token.
|
|
*/
|
|
function isKeywordToken(token) {
|
|
return token.type === "Keyword";
|
|
}
|
|
|
|
/**
|
|
* Gets the `(` token of the given function node.
|
|
* @param {ASTNode} node The function node to get.
|
|
* @param {SourceCode} sourceCode The source code object to get tokens.
|
|
* @returns {Token} `(` token.
|
|
*/
|
|
function getOpeningParenOfParams(node, sourceCode) {
|
|
|
|
// If the node is an arrow function and doesn't have parens, this returns the identifier of the first param.
|
|
if (node.type === "ArrowFunctionExpression" && node.params.length === 1) {
|
|
const argToken = sourceCode.getFirstToken(node.params[0]);
|
|
const maybeParenToken = sourceCode.getTokenBefore(argToken);
|
|
|
|
return isOpeningParenToken(maybeParenToken) ? maybeParenToken : argToken;
|
|
}
|
|
|
|
// Otherwise, returns paren.
|
|
return node.id
|
|
? sourceCode.getTokenAfter(node.id, isOpeningParenToken)
|
|
: sourceCode.getFirstToken(node, isOpeningParenToken);
|
|
}
|
|
|
|
/**
|
|
* Checks whether or not the tokens of two given nodes are same.
|
|
* @param {ASTNode} left A node 1 to compare.
|
|
* @param {ASTNode} right A node 2 to compare.
|
|
* @param {SourceCode} sourceCode The ESLint source code object.
|
|
* @returns {boolean} the source code for the given node.
|
|
*/
|
|
function equalTokens(left, right, sourceCode) {
|
|
const tokensL = sourceCode.getTokens(left);
|
|
const tokensR = sourceCode.getTokens(right);
|
|
|
|
if (tokensL.length !== tokensR.length) {
|
|
return false;
|
|
}
|
|
for (let i = 0; i < tokensL.length; ++i) {
|
|
if (tokensL[i].type !== tokensR[i].type ||
|
|
tokensL[i].value !== tokensR[i].value
|
|
) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Check if the given node is a true logical expression or not.
|
|
*
|
|
* The three binary expressions logical-or (`||`), logical-and (`&&`), and
|
|
* coalesce (`??`) are known as `ShortCircuitExpression`.
|
|
* But ESTree represents those by `LogicalExpression` node.
|
|
*
|
|
* This function rejects coalesce expressions of `LogicalExpression` node.
|
|
* @param {ASTNode} node The node to check.
|
|
* @returns {boolean} `true` if the node is `&&` or `||`.
|
|
* @see https://tc39.es/ecma262/#prod-ShortCircuitExpression
|
|
*/
|
|
function isLogicalExpression(node) {
|
|
return (
|
|
node.type === "LogicalExpression" &&
|
|
(node.operator === "&&" || node.operator === "||")
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Check if the given node is a nullish coalescing expression or not.
|
|
*
|
|
* The three binary expressions logical-or (`||`), logical-and (`&&`), and
|
|
* coalesce (`??`) are known as `ShortCircuitExpression`.
|
|
* But ESTree represents those by `LogicalExpression` node.
|
|
*
|
|
* This function finds only coalesce expressions of `LogicalExpression` node.
|
|
* @param {ASTNode} node The node to check.
|
|
* @returns {boolean} `true` if the node is `??`.
|
|
*/
|
|
function isCoalesceExpression(node) {
|
|
return node.type === "LogicalExpression" && node.operator === "??";
|
|
}
|
|
|
|
/**
|
|
* Check if given two nodes are the pair of a logical expression and a coalesce expression.
|
|
* @param {ASTNode} left A node to check.
|
|
* @param {ASTNode} right Another node to check.
|
|
* @returns {boolean} `true` if the two nodes are the pair of a logical expression and a coalesce expression.
|
|
*/
|
|
function isMixedLogicalAndCoalesceExpressions(left, right) {
|
|
return (
|
|
(isLogicalExpression(left) && isCoalesceExpression(right)) ||
|
|
(isCoalesceExpression(left) && isLogicalExpression(right))
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Checks if the given operator is a logical assignment operator.
|
|
* @param {string} operator The operator to check.
|
|
* @returns {boolean} `true` if the operator is a logical assignment operator.
|
|
*/
|
|
function isLogicalAssignmentOperator(operator) {
|
|
return LOGICAL_ASSIGNMENT_OPERATORS.has(operator);
|
|
}
|
|
|
|
/**
|
|
* Get the colon token of the given SwitchCase node.
|
|
* @param {ASTNode} node The SwitchCase node to get.
|
|
* @param {SourceCode} sourceCode The source code object to get tokens.
|
|
* @returns {Token} The colon token of the node.
|
|
*/
|
|
function getSwitchCaseColonToken(node, sourceCode) {
|
|
if (node.test) {
|
|
return sourceCode.getTokenAfter(node.test, isColonToken);
|
|
}
|
|
return sourceCode.getFirstToken(node, 1);
|
|
}
|
|
|
|
/**
|
|
* Gets ESM module export name represented by the given node.
|
|
* @param {ASTNode} node `Identifier` or string `Literal` node in a position
|
|
* that represents a module export name:
|
|
* - `ImportSpecifier#imported`
|
|
* - `ExportSpecifier#local` (if it is a re-export from another module)
|
|
* - `ExportSpecifier#exported`
|
|
* - `ExportAllDeclaration#exported`
|
|
* @returns {string} The module export name.
|
|
*/
|
|
function getModuleExportName(node) {
|
|
if (node.type === "Identifier") {
|
|
return node.name;
|
|
}
|
|
|
|
// string literal
|
|
return node.value;
|
|
}
|
|
|
|
/**
|
|
* Returns literal's value converted to the Boolean type
|
|
* @param {ASTNode} node any `Literal` node
|
|
* @returns {boolean | null} `true` when node is truthy, `false` when node is falsy,
|
|
* `null` when it cannot be determined.
|
|
*/
|
|
function getBooleanValue(node) {
|
|
if (node.value === null) {
|
|
|
|
/*
|
|
* it might be a null literal or bigint/regex literal in unsupported environments .
|
|
* https://github.com/estree/estree/blob/14df8a024956ea289bd55b9c2226a1d5b8a473ee/es5.md#regexpliteral
|
|
* https://github.com/estree/estree/blob/14df8a024956ea289bd55b9c2226a1d5b8a473ee/es2020.md#bigintliteral
|
|
*/
|
|
|
|
if (node.raw === "null") {
|
|
return false;
|
|
}
|
|
|
|
// regex is always truthy
|
|
if (typeof node.regex === "object") {
|
|
return true;
|
|
}
|
|
|
|
return null;
|
|
}
|
|
|
|
return !!node.value;
|
|
}
|
|
|
|
/**
|
|
* Checks if a branch node of LogicalExpression short circuits the whole condition
|
|
* @param {ASTNode} node The branch of main condition which needs to be checked
|
|
* @param {string} operator The operator of the main LogicalExpression.
|
|
* @returns {boolean} true when condition short circuits whole condition
|
|
*/
|
|
function isLogicalIdentity(node, operator) {
|
|
switch (node.type) {
|
|
case "Literal":
|
|
return (operator === "||" && getBooleanValue(node) === true) ||
|
|
(operator === "&&" && getBooleanValue(node) === false);
|
|
|
|
case "UnaryExpression":
|
|
return (operator === "&&" && node.operator === "void");
|
|
|
|
case "LogicalExpression":
|
|
|
|
/*
|
|
* handles `a && false || b`
|
|
* `false` is an identity element of `&&` but not `||`
|
|
*/
|
|
return operator === node.operator &&
|
|
(
|
|
isLogicalIdentity(node.left, operator) ||
|
|
isLogicalIdentity(node.right, operator)
|
|
);
|
|
|
|
case "AssignmentExpression":
|
|
return ["||=", "&&="].includes(node.operator) &&
|
|
operator === node.operator.slice(0, -1) &&
|
|
isLogicalIdentity(node.right, operator);
|
|
|
|
// no default
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Checks if an identifier is a reference to a global variable.
|
|
* @param {Scope} scope The scope in which the identifier is referenced.
|
|
* @param {ASTNode} node An identifier node to check.
|
|
* @returns {boolean} `true` if the identifier is a reference to a global variable.
|
|
*/
|
|
function isReferenceToGlobalVariable(scope, node) {
|
|
const reference = scope.references.find(ref => ref.identifier === node);
|
|
|
|
return Boolean(
|
|
reference &&
|
|
reference.resolved &&
|
|
reference.resolved.scope.type === "global" &&
|
|
reference.resolved.defs.length === 0
|
|
);
|
|
}
|
|
|
|
|
|
/**
|
|
* Checks if a node has a constant truthiness value.
|
|
* @param {Scope} scope Scope in which the node appears.
|
|
* @param {ASTNode} node The AST node to check.
|
|
* @param {boolean} inBooleanPosition `true` if checking the test of a
|
|
* condition. `false` in all other cases. When `false`, checks if -- for
|
|
* both string and number -- if coerced to that type, the value will
|
|
* be constant.
|
|
* @returns {boolean} true when node's truthiness is constant
|
|
* @private
|
|
*/
|
|
function isConstant(scope, node, inBooleanPosition) {
|
|
|
|
// node.elements can return null values in the case of sparse arrays ex. [,]
|
|
if (!node) {
|
|
return true;
|
|
}
|
|
switch (node.type) {
|
|
case "Literal":
|
|
case "ArrowFunctionExpression":
|
|
case "FunctionExpression":
|
|
return true;
|
|
case "ClassExpression":
|
|
case "ObjectExpression":
|
|
|
|
/**
|
|
* In theory objects like:
|
|
*
|
|
* `{toString: () => a}`
|
|
* `{valueOf: () => a}`
|
|
*
|
|
* Or a classes like:
|
|
*
|
|
* `class { static toString() { return a } }`
|
|
* `class { static valueOf() { return a } }`
|
|
*
|
|
* Are not constant verifiably when `inBooleanPosition` is
|
|
* false, but it's an edge case we've opted not to handle.
|
|
*/
|
|
return true;
|
|
case "TemplateLiteral":
|
|
return (inBooleanPosition && node.quasis.some(quasi => quasi.value.cooked.length)) ||
|
|
node.expressions.every(exp => isConstant(scope, exp, false));
|
|
|
|
case "ArrayExpression": {
|
|
if (!inBooleanPosition) {
|
|
return node.elements.every(element => isConstant(scope, element, false));
|
|
}
|
|
return true;
|
|
}
|
|
|
|
case "UnaryExpression":
|
|
if (
|
|
node.operator === "void" ||
|
|
node.operator === "typeof" && inBooleanPosition
|
|
) {
|
|
return true;
|
|
}
|
|
|
|
if (node.operator === "!") {
|
|
return isConstant(scope, node.argument, true);
|
|
}
|
|
|
|
return isConstant(scope, node.argument, false);
|
|
|
|
case "BinaryExpression":
|
|
return isConstant(scope, node.left, false) &&
|
|
isConstant(scope, node.right, false) &&
|
|
node.operator !== "in";
|
|
|
|
case "LogicalExpression": {
|
|
const isLeftConstant = isConstant(scope, node.left, inBooleanPosition);
|
|
const isRightConstant = isConstant(scope, node.right, inBooleanPosition);
|
|
const isLeftShortCircuit = (isLeftConstant && isLogicalIdentity(node.left, node.operator));
|
|
const isRightShortCircuit = (inBooleanPosition && isRightConstant && isLogicalIdentity(node.right, node.operator));
|
|
|
|
return (isLeftConstant && isRightConstant) ||
|
|
isLeftShortCircuit ||
|
|
isRightShortCircuit;
|
|
}
|
|
case "NewExpression":
|
|
return inBooleanPosition;
|
|
case "AssignmentExpression":
|
|
if (node.operator === "=") {
|
|
return isConstant(scope, node.right, inBooleanPosition);
|
|
}
|
|
|
|
if (["||=", "&&="].includes(node.operator) && inBooleanPosition) {
|
|
return isLogicalIdentity(node.right, node.operator.slice(0, -1));
|
|
}
|
|
|
|
return false;
|
|
|
|
case "SequenceExpression":
|
|
return isConstant(scope, node.expressions[node.expressions.length - 1], inBooleanPosition);
|
|
case "SpreadElement":
|
|
return isConstant(scope, node.argument, inBooleanPosition);
|
|
case "CallExpression":
|
|
if (node.callee.type === "Identifier" && node.callee.name === "Boolean") {
|
|
if (node.arguments.length === 0 || isConstant(scope, node.arguments[0], true)) {
|
|
return isReferenceToGlobalVariable(scope, node.callee);
|
|
}
|
|
}
|
|
return false;
|
|
case "Identifier":
|
|
return node.name === "undefined" && isReferenceToGlobalVariable(scope, node);
|
|
|
|
// no default
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Checks whether a node is an ExpressionStatement at the top level of a file or function body.
|
|
* A top-level ExpressionStatement node is a directive if it contains a single unparenthesized
|
|
* string literal and if it occurs either as the first sibling or immediately after another
|
|
* directive.
|
|
* @param {ASTNode} node The node to check.
|
|
* @returns {boolean} Whether or not the node is an ExpressionStatement at the top level of a
|
|
* file or function body.
|
|
*/
|
|
function isTopLevelExpressionStatement(node) {
|
|
if (node.type !== "ExpressionStatement") {
|
|
return false;
|
|
}
|
|
const parent = node.parent;
|
|
|
|
return parent.type === "Program" || (parent.type === "BlockStatement" && isFunction(parent.parent));
|
|
|
|
}
|
|
|
|
/**
|
|
* Check whether the given node is a part of a directive prologue or not.
|
|
* @param {ASTNode} node The node to check.
|
|
* @returns {boolean} `true` if the node is a part of directive prologue.
|
|
*/
|
|
function isDirective(node) {
|
|
return node.type === "ExpressionStatement" && typeof node.directive === "string";
|
|
}
|
|
|
|
/**
|
|
* Tests if a node appears at the beginning of an ancestor ExpressionStatement node.
|
|
* @param {ASTNode} node The node to check.
|
|
* @returns {boolean} Whether the node appears at the beginning of an ancestor ExpressionStatement node.
|
|
*/
|
|
function isStartOfExpressionStatement(node) {
|
|
const start = node.range[0];
|
|
let ancestor = node;
|
|
|
|
while ((ancestor = ancestor.parent) && ancestor.range[0] === start) {
|
|
if (ancestor.type === "ExpressionStatement") {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Determines whether an opening parenthesis `(`, bracket `[` or backtick ``` ` ``` needs to be preceded by a semicolon.
|
|
* This opening parenthesis or bracket should be at the start of an `ExpressionStatement` or at the start of the body of an `ArrowFunctionExpression`.
|
|
* @type {(sourceCode: SourceCode, node: ASTNode) => boolean}
|
|
* @param {SourceCode} sourceCode The source code object.
|
|
* @param {ASTNode} node A node at the position where an opening parenthesis or bracket will be inserted.
|
|
* @returns {boolean} Whether a semicolon is required before the opening parenthesis or braket.
|
|
*/
|
|
let needsPrecedingSemicolon;
|
|
|
|
{
|
|
const BREAK_OR_CONTINUE = new Set(["BreakStatement", "ContinueStatement"]);
|
|
|
|
// Declaration types that must contain a string Literal node at the end.
|
|
const DECLARATIONS = new Set(["ExportAllDeclaration", "ExportNamedDeclaration", "ImportDeclaration"]);
|
|
|
|
const IDENTIFIER_OR_KEYWORD = new Set(["Identifier", "Keyword"]);
|
|
|
|
// Keywords that can immediately precede an ExpressionStatement node, mapped to the their node types.
|
|
const NODE_TYPES_BY_KEYWORD = {
|
|
__proto__: null,
|
|
break: "BreakStatement",
|
|
continue: "ContinueStatement",
|
|
debugger: "DebuggerStatement",
|
|
do: "DoWhileStatement",
|
|
else: "IfStatement",
|
|
return: "ReturnStatement",
|
|
yield: "YieldExpression"
|
|
};
|
|
|
|
/*
|
|
* Before an opening parenthesis, postfix `++` and `--` always trigger ASI;
|
|
* the tokens `:`, `;`, `{` and `=>` don't expect a semicolon, as that would count as an empty statement.
|
|
*/
|
|
const PUNCTUATORS = new Set([":", ";", "{", "=>", "++", "--"]);
|
|
|
|
/*
|
|
* Statements that can contain an `ExpressionStatement` after a closing parenthesis.
|
|
* DoWhileStatement is an exception in that it always triggers ASI after the closing parenthesis.
|
|
*/
|
|
const STATEMENTS = new Set([
|
|
"DoWhileStatement",
|
|
"ForInStatement",
|
|
"ForOfStatement",
|
|
"ForStatement",
|
|
"IfStatement",
|
|
"WhileStatement",
|
|
"WithStatement"
|
|
]);
|
|
|
|
needsPrecedingSemicolon =
|
|
function(sourceCode, node) {
|
|
const prevToken = sourceCode.getTokenBefore(node);
|
|
|
|
if (!prevToken || prevToken.type === "Punctuator" && PUNCTUATORS.has(prevToken.value)) {
|
|
return false;
|
|
}
|
|
|
|
const prevNode = sourceCode.getNodeByRangeIndex(prevToken.range[0]);
|
|
|
|
if (isClosingParenToken(prevToken)) {
|
|
return !STATEMENTS.has(prevNode.type);
|
|
}
|
|
|
|
if (isClosingBraceToken(prevToken)) {
|
|
return (
|
|
prevNode.type === "BlockStatement" && prevNode.parent.type === "FunctionExpression" ||
|
|
prevNode.type === "ClassBody" && prevNode.parent.type === "ClassExpression" ||
|
|
prevNode.type === "ObjectExpression"
|
|
);
|
|
}
|
|
|
|
if (IDENTIFIER_OR_KEYWORD.has(prevToken.type)) {
|
|
if (BREAK_OR_CONTINUE.has(prevNode.parent.type)) {
|
|
return false;
|
|
}
|
|
|
|
const keyword = prevToken.value;
|
|
const nodeType = NODE_TYPES_BY_KEYWORD[keyword];
|
|
|
|
return prevNode.type !== nodeType;
|
|
}
|
|
|
|
if (prevToken.type === "String") {
|
|
return !DECLARATIONS.has(prevNode.parent.type);
|
|
}
|
|
|
|
return true;
|
|
};
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Public Interface
|
|
//------------------------------------------------------------------------------
|
|
|
|
module.exports = {
|
|
COMMENTS_IGNORE_PATTERN,
|
|
LINEBREAKS,
|
|
LINEBREAK_MATCHER: lineBreakPattern,
|
|
SHEBANG_MATCHER: shebangPattern,
|
|
STATEMENT_LIST_PARENTS,
|
|
|
|
/**
|
|
* Determines whether two adjacent tokens are on the same line.
|
|
* @param {Object} left The left token object.
|
|
* @param {Object} right The right token object.
|
|
* @returns {boolean} Whether or not the tokens are on the same line.
|
|
* @public
|
|
*/
|
|
isTokenOnSameLine(left, right) {
|
|
return left.loc.end.line === right.loc.start.line;
|
|
},
|
|
|
|
isNullOrUndefined,
|
|
isCallee,
|
|
isES5Constructor,
|
|
getUpperFunction,
|
|
isFunction,
|
|
isLoop,
|
|
isInLoop,
|
|
isArrayFromMethod,
|
|
isParenthesised,
|
|
createGlobalLinebreakMatcher,
|
|
equalTokens,
|
|
|
|
isArrowToken,
|
|
isClosingBraceToken,
|
|
isClosingBracketToken,
|
|
isClosingParenToken,
|
|
isColonToken,
|
|
isCommaToken,
|
|
isCommentToken,
|
|
isDotToken,
|
|
isQuestionDotToken,
|
|
isKeywordToken,
|
|
isNotClosingBraceToken: negate(isClosingBraceToken),
|
|
isNotClosingBracketToken: negate(isClosingBracketToken),
|
|
isNotClosingParenToken: negate(isClosingParenToken),
|
|
isNotColonToken: negate(isColonToken),
|
|
isNotCommaToken: negate(isCommaToken),
|
|
isNotDotToken: negate(isDotToken),
|
|
isNotQuestionDotToken: negate(isQuestionDotToken),
|
|
isNotOpeningBraceToken: negate(isOpeningBraceToken),
|
|
isNotOpeningBracketToken: negate(isOpeningBracketToken),
|
|
isNotOpeningParenToken: negate(isOpeningParenToken),
|
|
isNotSemicolonToken: negate(isSemicolonToken),
|
|
isOpeningBraceToken,
|
|
isOpeningBracketToken,
|
|
isOpeningParenToken,
|
|
isSemicolonToken,
|
|
isEqToken,
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
isStringLiteral(node) {
|
|
return (
|
|
(node.type === "Literal" && typeof node.value === "string") ||
|
|
node.type === "TemplateLiteral"
|
|
);
|
|
},
|
|
|
|
/**
|
|
* Checks whether a given node is a breakable statement or not.
|
|
* The node is breakable if the node is one of the following type:
|
|
*
|
|
* - DoWhileStatement
|
|
* - ForInStatement
|
|
* - ForOfStatement
|
|
* - ForStatement
|
|
* - SwitchStatement
|
|
* - WhileStatement
|
|
* @param {ASTNode} node A node to check.
|
|
* @returns {boolean} `true` if the node is breakable.
|
|
*/
|
|
isBreakableStatement(node) {
|
|
return breakableTypePattern.test(node.type);
|
|
},
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
getModifyingReferences(references) {
|
|
return references.filter(isModifyingReference);
|
|
},
|
|
|
|
/**
|
|
* 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.startsWith("eslint-") ||
|
|
node.type === "Block" && ESLINT_DIRECTIVE_PATTERN.test(comment)
|
|
);
|
|
},
|
|
|
|
/**
|
|
* 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 given node is not in `PropertyDefinition#value` position.
|
|
* - The given node is not `StaticBlock`.
|
|
* - The function name does not start with uppercase. It's a convention to capitalize the names
|
|
* of constructor functions. This check is not performed if `capIsConstructor` is set to `false`.
|
|
* - 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. Applies to anonymous
|
|
* functions only, as the name of the variable is considered to be the name of the function in this case.
|
|
* This check is not performed if `capIsConstructor` is set to `false`.
|
|
* - 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. It also can be an implicit function, like `StaticBlock`
|
|
* or any expression that is `PropertyDefinition#value` node.
|
|
* @param {SourceCode} sourceCode A SourceCode instance to get comments.
|
|
* @param {boolean} [capIsConstructor = true] `false` disables the assumption that functions which name starts
|
|
* with an uppercase or are assigned to a variable which name starts with an uppercase are constructors.
|
|
* @returns {boolean} The function node is the default `this` binding.
|
|
*/
|
|
isDefaultThisBinding(node, sourceCode, { capIsConstructor = true } = {}) {
|
|
|
|
/*
|
|
* Class field initializers are implicit functions, but ESTree doesn't have the AST node of field initializers.
|
|
* Therefore, A expression node at `PropertyDefinition#value` is a function.
|
|
* In this case, `this` is always not default binding.
|
|
*/
|
|
if (node.parent.type === "PropertyDefinition" && node.parent.value === node) {
|
|
return false;
|
|
}
|
|
|
|
// Class static blocks are implicit functions. In this case, `this` is always not default binding.
|
|
if (node.type === "StaticBlock") {
|
|
return false;
|
|
}
|
|
|
|
if (
|
|
(capIsConstructor && isES5Constructor(node)) ||
|
|
hasJSDocThisTag(node, sourceCode)
|
|
) {
|
|
return false;
|
|
}
|
|
const isAnonymous = node.id === null;
|
|
let currentNode = node;
|
|
|
|
while (currentNode) {
|
|
const parent = currentNode.parent;
|
|
|
|
switch (parent.type) {
|
|
|
|
/*
|
|
* Looks up the destination.
|
|
* e.g., obj.foo = nativeFoo || function foo() { ... };
|
|
*/
|
|
case "LogicalExpression":
|
|
case "ConditionalExpression":
|
|
case "ChainExpression":
|
|
currentNode = parent;
|
|
break;
|
|
|
|
/*
|
|
* If the upper function is IIFE, checks the destination of the return value.
|
|
* e.g.
|
|
* obj.foo = (function() {
|
|
* // setup...
|
|
* return function foo() { ... };
|
|
* })();
|
|
* obj.foo = (() =>
|
|
* function foo() { ... }
|
|
* )();
|
|
*/
|
|
case "ReturnStatement": {
|
|
const func = getUpperFunction(parent);
|
|
|
|
if (func === null || !isCallee(func)) {
|
|
return true;
|
|
}
|
|
currentNode = func.parent;
|
|
break;
|
|
}
|
|
case "ArrowFunctionExpression":
|
|
if (currentNode !== parent.body || !isCallee(parent)) {
|
|
return true;
|
|
}
|
|
currentNode = parent.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() { ... } }
|
|
* class A { foo = function() { ... } }
|
|
*/
|
|
case "Property":
|
|
case "PropertyDefinition":
|
|
case "MethodDefinition":
|
|
return parent.value !== currentNode;
|
|
|
|
/*
|
|
* e.g.
|
|
* obj.foo = function foo() { ... };
|
|
* Foo = function() { ... };
|
|
* [obj.foo = function foo() { ... }] = a;
|
|
* [Foo = function() { ... }] = a;
|
|
*/
|
|
case "AssignmentExpression":
|
|
case "AssignmentPattern":
|
|
if (parent.left.type === "MemberExpression") {
|
|
return false;
|
|
}
|
|
if (
|
|
capIsConstructor &&
|
|
isAnonymous &&
|
|
parent.left.type === "Identifier" &&
|
|
startsWithUpperCase(parent.left.name)
|
|
) {
|
|
return false;
|
|
}
|
|
return true;
|
|
|
|
/*
|
|
* e.g.
|
|
* var Foo = function() { ... };
|
|
*/
|
|
case "VariableDeclarator":
|
|
return !(
|
|
capIsConstructor &&
|
|
isAnonymous &&
|
|
parent.init === currentNode &&
|
|
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":
|
|
if (
|
|
parent.object === currentNode &&
|
|
isSpecificMemberAccess(parent, null, bindOrCallOrApplyPattern)
|
|
) {
|
|
const maybeCalleeNode = parent.parent.type === "ChainExpression"
|
|
? parent.parent
|
|
: parent;
|
|
|
|
return !(
|
|
isCallee(maybeCalleeNode) &&
|
|
maybeCalleeNode.parent.arguments.length >= 1 &&
|
|
!isNullOrUndefined(maybeCalleeNode.parent.arguments[0])
|
|
);
|
|
}
|
|
return true;
|
|
|
|
/*
|
|
* 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] !== currentNode ||
|
|
isNullOrUndefined(parent.arguments[1])
|
|
);
|
|
}
|
|
if (isArrayFromMethod(parent.callee)) {
|
|
return (
|
|
parent.arguments.length !== 3 ||
|
|
parent.arguments[1] !== currentNode ||
|
|
isNullOrUndefined(parent.arguments[2])
|
|
);
|
|
}
|
|
if (isMethodWhichHasThisArg(parent.callee)) {
|
|
return (
|
|
parent.arguments.length !== 2 ||
|
|
parent.arguments[0] !== currentNode ||
|
|
isNullOrUndefined(parent.arguments[1])
|
|
);
|
|
}
|
|
return true;
|
|
|
|
// Otherwise `this` is default.
|
|
default:
|
|
return true;
|
|
}
|
|
}
|
|
|
|
/* c8 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 "||":
|
|
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":
|
|
case "ChainExpression":
|
|
case "ImportExpression":
|
|
return 18;
|
|
|
|
case "NewExpression":
|
|
return 19;
|
|
|
|
default:
|
|
if (node.type in eslintVisitorKeys) {
|
|
return 20;
|
|
}
|
|
|
|
/*
|
|
* if the node is not a standard node that we know about, then assume it has the lowest precedence
|
|
* this will mean that rules will wrap unknown nodes in parentheses where applicable instead of
|
|
* unwrapping them and potentially changing the meaning of the code or introducing a syntax error.
|
|
*/
|
|
return -1;
|
|
}
|
|
},
|
|
|
|
/**
|
|
* 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);
|
|
},
|
|
|
|
/**
|
|
* 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
|
|
*
|
|
* 0 // true
|
|
* 5 // true
|
|
* 50 // true
|
|
* 5_000 // true
|
|
* 1_234_56 // true
|
|
* 08 // true
|
|
* 0192 // true
|
|
* 5. // false
|
|
* .5 // false
|
|
* 5.0 // false
|
|
* 5.00_00 // false
|
|
* 05 // false
|
|
* 0x5 // false
|
|
* 0b101 // false
|
|
* 0b11_01 // false
|
|
* 0o5 // false
|
|
* 5e0 // false
|
|
* 5e1_000 // false
|
|
* 5n // false
|
|
* 1_000n // false
|
|
* "5" // false
|
|
*
|
|
*/
|
|
isDecimalInteger(node) {
|
|
return node.type === "Literal" && typeof node.value === "number" &&
|
|
DECIMAL_INTEGER_PATTERN.test(node.raw);
|
|
},
|
|
|
|
/**
|
|
* Determines whether this token is a decimal integer numeric token.
|
|
* This is similar to isDecimalInteger(), but for tokens.
|
|
* @param {Token} token The token to check.
|
|
* @returns {boolean} `true` if this token is a decimal integer.
|
|
*/
|
|
isDecimalIntegerNumericToken(token) {
|
|
return token.type === "Numeric" && DECIMAL_INTEGER_PATTERN.test(token.value);
|
|
},
|
|
|
|
/**
|
|
* 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'`
|
|
* - `class A { foo = () => {}; }` .......... `method 'foo'`
|
|
* - `class A { foo = function() {}; }` ..... `method 'foo'`
|
|
* - `class A { foo = function bar() {}; }` . `method 'foo'`
|
|
* - `class A { static foo = () => {}; }` ... `static method 'foo'`
|
|
* - `class A { '#foo' = () => {}; }` ....... `method '#foo'`
|
|
* - `class A { #foo = () => {}; }` ......... `private method #foo`
|
|
* - `class A { static #foo = () => {}; }` .. `static private method #foo`
|
|
* - `class A { '#foo'() {} }` .............. `method '#foo'`
|
|
* - `class A { #foo() {} }` ................ `private method #foo`
|
|
* - `class A { static #foo() {} }` ......... `static private method #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.type === "PropertyDefinition") {
|
|
|
|
// The proposal uses `static` word consistently before visibility words: https://github.com/tc39/proposal-static-class-features
|
|
if (parent.static) {
|
|
tokens.push("static");
|
|
}
|
|
if (!parent.computed && parent.key.type === "PrivateIdentifier") {
|
|
tokens.push("private");
|
|
}
|
|
}
|
|
if (node.async) {
|
|
tokens.push("async");
|
|
}
|
|
if (node.generator) {
|
|
tokens.push("generator");
|
|
}
|
|
|
|
if (parent.type === "Property" || parent.type === "MethodDefinition") {
|
|
if (parent.kind === "constructor") {
|
|
return "constructor";
|
|
}
|
|
if (parent.kind === "get") {
|
|
tokens.push("getter");
|
|
} else if (parent.kind === "set") {
|
|
tokens.push("setter");
|
|
} else {
|
|
tokens.push("method");
|
|
}
|
|
} else if (parent.type === "PropertyDefinition") {
|
|
tokens.push("method");
|
|
} else {
|
|
if (node.type === "ArrowFunctionExpression") {
|
|
tokens.push("arrow");
|
|
}
|
|
tokens.push("function");
|
|
}
|
|
|
|
if (parent.type === "Property" || parent.type === "MethodDefinition" || parent.type === "PropertyDefinition") {
|
|
if (!parent.computed && parent.key.type === "PrivateIdentifier") {
|
|
tokens.push(`#${parent.key.name}`);
|
|
} else {
|
|
const name = getStaticPropertyName(parent);
|
|
|
|
if (name !== null) {
|
|
tokens.push(`'${name}'`);
|
|
} else if (node.id) {
|
|
tokens.push(`'${node.id.name}'`);
|
|
}
|
|
}
|
|
} else if (node.id) {
|
|
tokens.push(`'${node.id.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) {} }`
|
|
* ^^^^^^^^^^^^^^
|
|
* - `class A { foo = function() {} }`
|
|
* ^^^^^^^^^^^^^^
|
|
* - `class A { static foo = function() {} }`
|
|
* ^^^^^^^^^^^^^^^^^^^^^
|
|
* - `class A { foo = (a, b) => {} }`
|
|
* ^^^^^^
|
|
* @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 (parent.type === "Property" || parent.type === "MethodDefinition" || parent.type === "PropertyDefinition") {
|
|
start = parent.loc.start;
|
|
end = getOpeningParenOfParams(node, sourceCode).loc.start;
|
|
} else if (node.type === "ArrowFunctionExpression") {
|
|
const arrowToken = sourceCode.getTokenBefore(node.body, isArrowToken);
|
|
|
|
start = arrowToken.loc.start;
|
|
end = arrowToken.loc.end;
|
|
} else {
|
|
start = node.loc.start;
|
|
end = getOpeningParenOfParams(node, sourceCode).loc.start;
|
|
}
|
|
|
|
return {
|
|
start: Object.assign({}, start),
|
|
end: Object.assign({}, end)
|
|
};
|
|
},
|
|
|
|
/**
|
|
* Gets next location when the result is not out of bound, otherwise returns null.
|
|
*
|
|
* Assumptions:
|
|
*
|
|
* - The given location represents a valid location in the given source code.
|
|
* - Columns are 0-based.
|
|
* - Lines are 1-based.
|
|
* - Column immediately after the last character in a line (not incl. linebreaks) is considered to be a valid location.
|
|
* - If the source code ends with a linebreak, `sourceCode.lines` array will have an extra element (empty string) at the end.
|
|
* The start (column 0) of that extra line is considered to be a valid location.
|
|
*
|
|
* Examples of successive locations (line, column):
|
|
*
|
|
* code: foo
|
|
* locations: (1, 0) -> (1, 1) -> (1, 2) -> (1, 3) -> null
|
|
*
|
|
* code: foo<LF>
|
|
* locations: (1, 0) -> (1, 1) -> (1, 2) -> (1, 3) -> (2, 0) -> null
|
|
*
|
|
* code: foo<CR><LF>
|
|
* locations: (1, 0) -> (1, 1) -> (1, 2) -> (1, 3) -> (2, 0) -> null
|
|
*
|
|
* code: a<LF>b
|
|
* locations: (1, 0) -> (1, 1) -> (2, 0) -> (2, 1) -> null
|
|
*
|
|
* code: a<LF>b<LF>
|
|
* locations: (1, 0) -> (1, 1) -> (2, 0) -> (2, 1) -> (3, 0) -> null
|
|
*
|
|
* code: a<CR><LF>b<CR><LF>
|
|
* locations: (1, 0) -> (1, 1) -> (2, 0) -> (2, 1) -> (3, 0) -> null
|
|
*
|
|
* code: a<LF><LF>
|
|
* locations: (1, 0) -> (1, 1) -> (2, 0) -> (3, 0) -> null
|
|
*
|
|
* code: <LF>
|
|
* locations: (1, 0) -> (2, 0) -> null
|
|
*
|
|
* code:
|
|
* locations: (1, 0) -> null
|
|
* @param {SourceCode} sourceCode The sourceCode
|
|
* @param {{line: number, column: number}} location The location
|
|
* @returns {{line: number, column: number} | null} Next location
|
|
*/
|
|
getNextLocation(sourceCode, { line, column }) {
|
|
if (column < sourceCode.lines[line - 1].length) {
|
|
return {
|
|
line,
|
|
column: column + 1
|
|
};
|
|
}
|
|
|
|
if (line < sourceCode.lines.length) {
|
|
return {
|
|
line: line + 1,
|
|
column: 0
|
|
};
|
|
}
|
|
|
|
return null;
|
|
},
|
|
|
|
/**
|
|
* 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 possibility 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":
|
|
case "ChainExpression":
|
|
return true; // possibly an error object.
|
|
|
|
case "AssignmentExpression":
|
|
if (["=", "&&="].includes(node.operator)) {
|
|
return module.exports.couldBeError(node.right);
|
|
}
|
|
|
|
if (["||=", "??="].includes(node.operator)) {
|
|
return module.exports.couldBeError(node.left) || module.exports.couldBeError(node.right);
|
|
}
|
|
|
|
/**
|
|
* All other assignment operators are mathematical assignment operators (arithmetic or bitwise).
|
|
* An assignment expression with a mathematical operator can either evaluate to a primitive value,
|
|
* or throw, depending on the operands. Thus, it cannot evaluate to an `Error` object.
|
|
*/
|
|
return false;
|
|
|
|
case "SequenceExpression": {
|
|
const exprs = node.expressions;
|
|
|
|
return exprs.length !== 0 && module.exports.couldBeError(exprs[exprs.length - 1]);
|
|
}
|
|
|
|
case "LogicalExpression":
|
|
|
|
/*
|
|
* If the && operator short-circuits, the left side was falsy and therefore not an error, and if it
|
|
* doesn't short-circuit, it takes the value from the right side, so the right side must always be
|
|
* a plausible error. A future improvement could verify that the left side could be truthy by
|
|
* excluding falsy literals.
|
|
*/
|
|
if (node.operator === "&&") {
|
|
return module.exports.couldBeError(node.right);
|
|
}
|
|
|
|
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;
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Check if a given node is a numeric literal or not.
|
|
* @param {ASTNode} node The node to check.
|
|
* @returns {boolean} `true` if the node is a number or bigint literal.
|
|
*/
|
|
isNumericLiteral(node) {
|
|
return (
|
|
node.type === "Literal" &&
|
|
(typeof node.value === "number" || Boolean(node.bigint))
|
|
);
|
|
},
|
|
|
|
/**
|
|
* 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) {
|
|
const espreeOptions = {
|
|
ecmaVersion: espree.latestEcmaVersion,
|
|
comment: true,
|
|
range: true
|
|
};
|
|
|
|
let leftToken;
|
|
|
|
if (typeof leftValue === "string") {
|
|
let tokens;
|
|
|
|
try {
|
|
tokens = espree.tokenize(leftValue, espreeOptions);
|
|
} catch {
|
|
return false;
|
|
}
|
|
|
|
const comments = tokens.comments;
|
|
|
|
leftToken = tokens[tokens.length - 1];
|
|
if (comments.length) {
|
|
const lastComment = comments[comments.length - 1];
|
|
|
|
if (!leftToken || lastComment.range[0] > leftToken.range[0]) {
|
|
leftToken = lastComment;
|
|
}
|
|
}
|
|
} else {
|
|
leftToken = leftValue;
|
|
}
|
|
|
|
/*
|
|
* If a hashbang comment was passed as a token object from SourceCode,
|
|
* its type will be "Shebang" because of the way ESLint itself handles hashbangs.
|
|
* If a hashbang comment was passed in a string and then tokenized in this function,
|
|
* its type will be "Hashbang" because of the way Espree tokenizes hashbangs.
|
|
*/
|
|
if (leftToken.type === "Shebang" || leftToken.type === "Hashbang") {
|
|
return false;
|
|
}
|
|
|
|
let rightToken;
|
|
|
|
if (typeof rightValue === "string") {
|
|
let tokens;
|
|
|
|
try {
|
|
tokens = espree.tokenize(rightValue, espreeOptions);
|
|
} catch {
|
|
return false;
|
|
}
|
|
|
|
const comments = tokens.comments;
|
|
|
|
rightToken = tokens[0];
|
|
if (comments.length) {
|
|
const firstComment = comments[0];
|
|
|
|
if (!rightToken || firstComment.range[0] < rightToken.range[0]) {
|
|
rightToken = firstComment;
|
|
}
|
|
}
|
|
} else {
|
|
rightToken = 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)
|
|
);
|
|
}
|
|
if (leftToken.type === "Punctuator" && leftToken.value === "/") {
|
|
return !["Block", "Line", "RegularExpression"].includes(rightToken.type);
|
|
}
|
|
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;
|
|
}
|
|
|
|
if (leftToken.type === "Block" || rightToken.type === "Block" || rightToken.type === "Line") {
|
|
return true;
|
|
}
|
|
|
|
if (rightToken.type === "PrivateIdentifier") {
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
},
|
|
|
|
/**
|
|
* Get the `loc` object of a given name in a `/*globals` directive comment.
|
|
* @param {SourceCode} sourceCode The source code to convert index to loc.
|
|
* @param {Comment} comment The `/*globals` directive comment which include the name.
|
|
* @param {string} name The name to find.
|
|
* @returns {SourceLocation} The `loc` object.
|
|
*/
|
|
getNameLocationInGlobalDirectiveComment(sourceCode, comment, name) {
|
|
const namePattern = new RegExp(`[\\s,]${escapeRegExp(name)}(?:$|[\\s,:])`, "gu");
|
|
|
|
// To ignore the first text "global".
|
|
namePattern.lastIndex = comment.value.indexOf("global") + 6;
|
|
|
|
// Search a given variable name.
|
|
const match = namePattern.exec(comment.value);
|
|
|
|
// Convert the index to loc.
|
|
const start = sourceCode.getLocFromIndex(
|
|
comment.range[0] +
|
|
"/*".length +
|
|
(match ? match.index + 1 : 0)
|
|
);
|
|
const end = {
|
|
line: start.line,
|
|
column: start.column + (match ? name.length : 1)
|
|
};
|
|
|
|
return { start, end };
|
|
},
|
|
|
|
/**
|
|
* Determines whether the given raw string contains an octal escape sequence
|
|
* or a non-octal decimal escape sequence ("\8", "\9").
|
|
*
|
|
* "\1", "\2" ... "\7", "\8", "\9"
|
|
* "\00", "\01" ... "\07", "\08", "\09"
|
|
*
|
|
* "\0", when not followed by a digit, is not an octal escape sequence.
|
|
* @param {string} rawString A string in its raw representation.
|
|
* @returns {boolean} `true` if the string contains at least one octal escape sequence
|
|
* or at least one non-octal decimal escape sequence.
|
|
*/
|
|
hasOctalOrNonOctalDecimalEscapeSequence(rawString) {
|
|
return OCTAL_OR_NON_OCTAL_DECIMAL_ESCAPE_PATTERN.test(rawString);
|
|
},
|
|
|
|
/**
|
|
* Determines whether the given node is a template literal without expressions.
|
|
* @param {ASTNode} node Node to check.
|
|
* @returns {boolean} True if the node is a template literal without expressions.
|
|
*/
|
|
isStaticTemplateLiteral(node) {
|
|
return node.type === "TemplateLiteral" && node.expressions.length === 0;
|
|
},
|
|
|
|
isReferenceToGlobalVariable,
|
|
isLogicalExpression,
|
|
isCoalesceExpression,
|
|
isMixedLogicalAndCoalesceExpressions,
|
|
isNullLiteral,
|
|
getStaticStringValue,
|
|
getStaticPropertyName,
|
|
skipChainExpression,
|
|
isSpecificId,
|
|
isSpecificMemberAccess,
|
|
equalLiteralValue,
|
|
isSameReference,
|
|
isLogicalAssignmentOperator,
|
|
getSwitchCaseColonToken,
|
|
getModuleExportName,
|
|
isConstant,
|
|
isTopLevelExpressionStatement,
|
|
isDirective,
|
|
isStartOfExpressionStatement,
|
|
needsPrecedingSemicolon
|
|
};
|