--- /dev/null
+/**
+ * @fileoverview Common utils for AST.
+ * @author Gyandeep Singh
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const esutils = require("esutils");
+const espree = require("espree");
+const lodash = require("lodash");
+const {
+ breakableTypePattern,
+ createGlobalLinebreakMatcher,
+ lineBreakPattern,
+ shebangPattern
+} = require("../../shared/ast-utils");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+const anyFunctionPattern = /^(?:Function(?:Declaration|Expression)|ArrowFunctionExpression)$/u;
+const anyLoopPattern = /^(?:DoWhile|For|ForIn|ForOf|While)Statement$/u;
+const arrayOrTypedArrayPattern = /Array$/u;
+const arrayMethodPattern = /^(?:every|filter|find|findIndex|forEach|map|some)$/u;
+const bindOrCallOrApplyPattern = /^(?:bind|call|apply)$/u;
+const thisTagPattern = /^[\s*]*@this/mu;
+
+
+const COMMENTS_IGNORE_PATTERN = /^\s*(?:eslint|jshint\s+|jslint\s+|istanbul\s+|globals?\s+|exported\s+|jscs)/u;
+const LINEBREAKS = new Set(["\r\n", "\r", "\n", "\u2028", "\u2029"]);
+
+// A set of node types that can contain a list of statements
+const STATEMENT_LIST_PARENTS = new Set(["Program", "BlockStatement", "SwitchCase"]);
+
+const DECIMAL_INTEGER_PATTERN = /^(0|[1-9]\d*)$/u;
+const OCTAL_ESCAPE_PATTERN = /^(?:[^\\]|\\[^0-7]|\\0(?![0-9]))*\\(?:[1-7]|0[0-9])/u;
+
+/**
+ * Checks reference if is non initializer and writable.
+ * @param {Reference} reference A reference to check.
+ * @param {int} index The index of the reference in the references.
+ * @param {Reference[]} references The array that the reference belongs to.
+ * @returns {boolean} Success/Failure
+ * @private
+ */
+function isModifyingReference(reference, index, references) {
+ const identifier = reference.identifier;
+
+ /*
+ * Destructuring assignments can have multiple default value, so
+ * possibly there are multiple writeable references for the same
+ * identifier.
+ */
+ const modifyingDifferentIdentifier = index === 0 ||
+ references[index - 1].identifier !== identifier;
+
+ return (identifier &&
+ reference.init === false &&
+ reference.isWrite() &&
+ modifyingDifferentIdentifier
+ );
+}
+
+/**
+ * Checks whether the given string starts with uppercase or not.
+ * @param {string} s The string to check.
+ * @returns {boolean} `true` if the string starts with uppercase.
+ */
+function startsWithUpperCase(s) {
+ return s[0] !== s[0].toLocaleLowerCase();
+}
+
+/**
+ * Checks whether or not a node is a constructor.
+ * @param {ASTNode} node A function node to check.
+ * @returns {boolean} Wehether or not a node is a constructor.
+ */
+function isES5Constructor(node) {
+ return (node.id && startsWithUpperCase(node.id.name));
+}
+
+/**
+ * Finds a function node from ancestors of a node.
+ * @param {ASTNode} node A start node to find.
+ * @returns {Node|null} A found function node.
+ */
+function getUpperFunction(node) {
+ for (let currentNode = node; currentNode; currentNode = currentNode.parent) {
+ if (anyFunctionPattern.test(currentNode.type)) {
+ return currentNode;
+ }
+ }
+ return null;
+}
+
+/**
+ * Checks whether a given node is a function node or not.
+ * The following types are function nodes:
+ *
+ * - ArrowFunctionExpression
+ * - FunctionDeclaration
+ * - FunctionExpression
+ * @param {ASTNode|null} node A node to check.
+ * @returns {boolean} `true` if the node is a function node.
+ */
+function isFunction(node) {
+ return Boolean(node && anyFunctionPattern.test(node.type));
+}
+
+/**
+ * Checks whether a given node is a loop node or not.
+ * The following types are loop nodes:
+ *
+ * - DoWhileStatement
+ * - ForInStatement
+ * - ForOfStatement
+ * - ForStatement
+ * - WhileStatement
+ * @param {ASTNode|null} node A node to check.
+ * @returns {boolean} `true` if the node is a loop node.
+ */
+function isLoop(node) {
+ return Boolean(node && anyLoopPattern.test(node.type));
+}
+
+/**
+ * Checks whether the given node is in a loop or not.
+ * @param {ASTNode} node The node to check.
+ * @returns {boolean} `true` if the node is in a loop.
+ */
+function isInLoop(node) {
+ for (let currentNode = node; currentNode && !isFunction(currentNode); currentNode = currentNode.parent) {
+ if (isLoop(currentNode)) {
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/**
+ * Checks whether or not a node is `null` or `undefined`.
+ * @param {ASTNode} node A node to check.
+ * @returns {boolean} Whether or not the node is a `null` or `undefined`.
+ * @public
+ */
+function isNullOrUndefined(node) {
+ return (
+ module.exports.isNullLiteral(node) ||
+ (node.type === "Identifier" && node.name === "undefined") ||
+ (node.type === "UnaryExpression" && node.operator === "void")
+ );
+}
+
+/**
+ * Checks whether or not a node is callee.
+ * @param {ASTNode} node A node to check.
+ * @returns {boolean} Whether or not the node is callee.
+ */
+function isCallee(node) {
+ return node.parent.type === "CallExpression" && node.parent.callee === node;
+}
+
+/**
+ * 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 (
+ node.type === "MemberExpression" &&
+ node.object.type === "Identifier" &&
+ node.object.name === "Reflect" &&
+ node.property.type === "Identifier" &&
+ node.property.name === "apply" &&
+ node.computed === false
+ );
+}
+
+/**
+ * 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 (
+ node.type === "MemberExpression" &&
+ node.object.type === "Identifier" &&
+ arrayOrTypedArrayPattern.test(node.object.name) &&
+ node.property.type === "Identifier" &&
+ node.property.name === "from" &&
+ node.computed === false
+ );
+}
+
+/**
+ * Checks whether or not a node is a method which has `thisArg`.
+ * @param {ASTNode} node A node to check.
+ * @returns {boolean} Whether or not the node is a method which has `thisArg`.
+ */
+function isMethodWhichHasThisArg(node) {
+ for (
+ let currentNode = node;
+ currentNode.type === "MemberExpression" && !currentNode.computed;
+ currentNode = currentNode.property
+ ) {
+ if (currentNode.property.type === "Identifier") {
+ return arrayMethodPattern.test(currentNode.property.name);
+ }
+ }
+
+ return false;
+}
+
+/**
+ * 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 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 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) {
+ 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;
+}
+
+//------------------------------------------------------------------------------
+// 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,
+ isKeywordToken,
+ isNotClosingBraceToken: negate(isClosingBraceToken),
+ isNotClosingBracketToken: negate(isClosingBracketToken),
+ isNotClosingParenToken: negate(isClosingParenToken),
+ isNotColonToken: negate(isColonToken),
+ isNotCommaToken: negate(isCommaToken),
+ isNotDotToken: negate(isDotToken),
+ isNotOpeningBraceToken: negate(isOpeningBraceToken),
+ isNotOpeningBracketToken: negate(isOpeningBracketToken),
+ isNotOpeningParenToken: negate(isOpeningParenToken),
+ isNotSemicolonToken: negate(isSemicolonToken),
+ isOpeningBraceToken,
+ isOpeningBracketToken,
+ isOpeningParenToken,
+ 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.
+ */
+ 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.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 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.
+ * @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 } = {}) {
+ 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":
+ 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() { ... } }
+ */
+ case "Property":
+ 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":
+ return (
+ parent.object !== currentNode ||
+ 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] !== 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;
+ }
+ }
+
+ /* 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":
+ case "ImportExpression":
+ return 18;
+
+ case "NewExpression":
+ return 19;
+
+ 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" &&
+ 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'`
+ * @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";
+ }
+ 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(`'${node.id.name}'`);
+ } else {
+ const name = module.exports.getStaticPropertyName(parent);
+
+ if (name !== null) {
+ tokens.push(`'${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 next location when the result is not out of bound, otherwise returns null.
+ * @param {SourceCode} sourceCode The sourceCode
+ * @param {{line: number, column: number}} location The location
+ * @returns {{line: number, column: number} | null} Next location
+ */
+ getNextLocation(sourceCode, location) {
+ const index = sourceCode.getIndexFromLoc(location);
+
+ // Avoid out of bound location
+ if (index + 1 > sourceCode.text.length) {
+ return null;
+ }
+
+ return sourceCode.getLocFromIndex(index + 1);
+ },
+
+ /**
+ * 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 && !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) {
+ 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;
+ },
+
+ /**
+ * 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,]${lodash.escapeRegExp(name)}(?:$|[\\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.
+ return sourceCode.getLocFromIndex(
+ comment.range[0] +
+ "/*".length +
+ (match ? match.index + 1 : 0)
+ );
+ },
+
+ /**
+ * Determines whether the given raw string contains an octal escape sequence.
+ *
+ * "\1", "\2" ... "\7"
+ * "\00", "\01" ... "\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.
+ */
+ hasOctalEscapeSequence(rawString) {
+ return OCTAL_ESCAPE_PATTERN.test(rawString);
+ }
+};
projects / dotfiles / .git / blobdiff