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/**
* @fileoverview Abstraction of JavaScript source code.
* @author Nicholas C. Zakas
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const
{ isCommentToken } = require("@eslint-community/eslint-utils"),
TokenStore = require("./token-store"),
astUtils = require("../../../shared/ast-utils"),
Traverser = require("../../../shared/traverser"),
globals = require("../../../../conf/globals"),
{
directivesPattern
} = require("../../../shared/directives"),
CodePathAnalyzer = require("../../../linter/code-path-analysis/code-path-analyzer"),
createEmitter = require("../../../linter/safe-emitter"),
{ ConfigCommentParser, VisitNodeStep, CallMethodStep, Directive } = require("@eslint/plugin-kit"),
eslintScope = require("eslint-scope");
//------------------------------------------------------------------------------
// Type Definitions
//------------------------------------------------------------------------------
/** @typedef {import("eslint-scope").Variable} Variable */
/** @typedef {import("eslint-scope").Scope} Scope */
/** @typedef {import("@eslint/core").SourceCode} ISourceCode */
/** @typedef {import("@eslint/core").Directive} IDirective */
/** @typedef {import("@eslint/core").TraversalStep} ITraversalStep */
//------------------------------------------------------------------------------
// Private
//------------------------------------------------------------------------------
const commentParser = new ConfigCommentParser();
const CODE_PATH_EVENTS = [
"onCodePathStart",
"onCodePathEnd",
"onCodePathSegmentStart",
"onCodePathSegmentEnd",
"onCodePathSegmentLoop",
"onUnreachableCodePathSegmentStart",
"onUnreachableCodePathSegmentEnd"
];
/**
* Validates that the given AST has the required information.
* @param {ASTNode} ast The Program node of the AST to check.
* @throws {Error} If the AST doesn't contain the correct information.
* @returns {void}
* @private
*/
function validate(ast) {
if (!ast.tokens) {
throw new Error("AST is missing the tokens array.");
}
if (!ast.comments) {
throw new Error("AST is missing the comments array.");
}
if (!ast.loc) {
throw new Error("AST is missing location information.");
}
if (!ast.range) {
throw new Error("AST is missing range information");
}
}
/**
* Retrieves globals for the given ecmaVersion.
* @param {number} ecmaVersion The version to retrieve globals for.
* @returns {Object} The globals for the given ecmaVersion.
*/
function getGlobalsForEcmaVersion(ecmaVersion) {
switch (ecmaVersion) {
case 3:
return globals.es3;
case 5:
return globals.es5;
default:
if (ecmaVersion < 2015) {
return globals[`es${ecmaVersion + 2009}`];
}
return globals[`es${ecmaVersion}`];
}
}
/**
* Check to see if its a ES6 export declaration.
* @param {ASTNode} astNode An AST node.
* @returns {boolean} whether the given node represents an export declaration.
* @private
*/
function looksLikeExport(astNode) {
return astNode.type === "ExportDefaultDeclaration" || astNode.type === "ExportNamedDeclaration" ||
astNode.type === "ExportAllDeclaration" || astNode.type === "ExportSpecifier";
}
/**
* Merges two sorted lists into a larger sorted list in O(n) time.
* @param {Token[]} tokens The list of tokens.
* @param {Token[]} comments The list of comments.
* @returns {Token[]} A sorted list of tokens and comments.
* @private
*/
function sortedMerge(tokens, comments) {
const result = [];
let tokenIndex = 0;
let commentIndex = 0;
while (tokenIndex < tokens.length || commentIndex < comments.length) {
if (commentIndex >= comments.length || tokenIndex < tokens.length && tokens[tokenIndex].range[0] < comments[commentIndex].range[0]) {
result.push(tokens[tokenIndex++]);
} else {
result.push(comments[commentIndex++]);
}
}
return result;
}
/**
* Normalizes a value for a global in a config
* @param {(boolean|string|null)} configuredValue The value given for a global in configuration or in
* a global directive comment
* @returns {("readable"|"writeable"|"off")} The value normalized as a string
* @throws Error if global value is invalid
*/
function normalizeConfigGlobal(configuredValue) {
switch (configuredValue) {
case "off":
return "off";
case true:
case "true":
case "writeable":
case "writable":
return "writable";
case null:
case false:
case "false":
case "readable":
case "readonly":
return "readonly";
default:
throw new Error(`'${configuredValue}' is not a valid configuration for a global (use 'readonly', 'writable', or 'off')`);
}
}
/**
* Determines if two nodes or tokens overlap.
* @param {ASTNode|Token} first The first node or token to check.
* @param {ASTNode|Token} second The second node or token to check.
* @returns {boolean} True if the two nodes or tokens overlap.
* @private
*/
function nodesOrTokensOverlap(first, second) {
return (first.range[0] <= second.range[0] && first.range[1] >= second.range[0]) ||
(second.range[0] <= first.range[0] && second.range[1] >= first.range[0]);
}
/**
* Determines if two nodes or tokens have at least one whitespace character
* between them. Order does not matter. Returns false if the given nodes or
* tokens overlap.
* @param {SourceCode} sourceCode The source code object.
* @param {ASTNode|Token} first The first node or token to check between.
* @param {ASTNode|Token} second The second node or token to check between.
* @param {boolean} checkInsideOfJSXText If `true` is present, check inside of JSXText tokens for backward compatibility.
* @returns {boolean} True if there is a whitespace character between
* any of the tokens found between the two given nodes or tokens.
* @public
*/
function isSpaceBetween(sourceCode, first, second, checkInsideOfJSXText) {
if (nodesOrTokensOverlap(first, second)) {
return false;
}
const [startingNodeOrToken, endingNodeOrToken] = first.range[1] <= second.range[0]
? [first, second]
: [second, first];
const firstToken = sourceCode.getLastToken(startingNodeOrToken) || startingNodeOrToken;
const finalToken = sourceCode.getFirstToken(endingNodeOrToken) || endingNodeOrToken;
let currentToken = firstToken;
while (currentToken !== finalToken) {
const nextToken = sourceCode.getTokenAfter(currentToken, { includeComments: true });
if (
currentToken.range[1] !== nextToken.range[0] ||
/*
* For backward compatibility, check spaces in JSXText.
* https://github.com/eslint/eslint/issues/12614
*/
(
checkInsideOfJSXText &&
nextToken !== finalToken &&
nextToken.type === "JSXText" &&
/\s/u.test(nextToken.value)
)
) {
return true;
}
currentToken = nextToken;
}
return false;
}
//-----------------------------------------------------------------------------
// Directive Comments
//-----------------------------------------------------------------------------
/**
* Ensures that variables representing built-in properties of the Global Object,
* and any globals declared by special block comments, are present in the global
* scope.
* @param {Scope} globalScope The global scope.
* @param {Object|undefined} configGlobals The globals declared in configuration
* @param {Object|undefined} inlineGlobals The globals declared in the source code
* @returns {void}
*/
function addDeclaredGlobals(globalScope, configGlobals = {}, inlineGlobals = {}) {
// Define configured global variables.
for (const id of new Set([...Object.keys(configGlobals), ...Object.keys(inlineGlobals)])) {
/*
* `normalizeConfigGlobal` will throw an error if a configured global value is invalid. However, these errors would
* typically be caught when validating a config anyway (validity for inline global comments is checked separately).
*/
const configValue = configGlobals[id] === void 0 ? void 0 : normalizeConfigGlobal(configGlobals[id]);
const commentValue = inlineGlobals[id] && inlineGlobals[id].value;
const value = commentValue || configValue;
const sourceComments = inlineGlobals[id] && inlineGlobals[id].comments;
if (value === "off") {
continue;
}
let variable = globalScope.set.get(id);
if (!variable) {
variable = new eslintScope.Variable(id, globalScope);
globalScope.variables.push(variable);
globalScope.set.set(id, variable);
}
variable.eslintImplicitGlobalSetting = configValue;
variable.eslintExplicitGlobal = sourceComments !== void 0;
variable.eslintExplicitGlobalComments = sourceComments;
variable.writeable = (value === "writable");
}
/*
* "through" contains all references which definitions cannot be found.
* Since we augment the global scope using configuration, we need to update
* references and remove the ones that were added by configuration.
*/
globalScope.through = globalScope.through.filter(reference => {
const name = reference.identifier.name;
const variable = globalScope.set.get(name);
if (variable) {
/*
* Links the variable and the reference.
* And this reference is removed from `Scope#through`.
*/
reference.resolved = variable;
variable.references.push(reference);
return false;
}
return true;
});
}
/**
* Sets the given variable names as exported so they won't be triggered by
* the `no-unused-vars` rule.
* @param {eslint.Scope} globalScope The global scope to define exports in.
* @param {Record<string,string>} variables An object whose keys are the variable
* names to export.
* @returns {void}
*/
function markExportedVariables(globalScope, variables) {
Object.keys(variables).forEach(name => {
const variable = globalScope.set.get(name);
if (variable) {
variable.eslintUsed = true;
variable.eslintExported = true;
}
});
}
//------------------------------------------------------------------------------
// Public Interface
//------------------------------------------------------------------------------
const caches = Symbol("caches");
/**
* Represents parsed source code.
* @implements {ISourceCode}
*/
class SourceCode extends TokenStore {
/**
* The cache of steps that were taken while traversing the source code.
* @type {Array<ITraversalStep>}
*/
#steps;
/**
* Creates a new instance.
* @param {string|Object} textOrConfig The source code text or config object.
* @param {string} textOrConfig.text The source code text.
* @param {ASTNode} textOrConfig.ast The Program node of the AST representing the code. This AST should be created from the text that BOM was stripped.
* @param {boolean} textOrConfig.hasBOM Indicates if the text has a Unicode BOM.
* @param {Object|null} textOrConfig.parserServices The parser services.
* @param {ScopeManager|null} textOrConfig.scopeManager The scope of this source code.
* @param {Object|null} textOrConfig.visitorKeys The visitor keys to traverse AST.
* @param {ASTNode} [astIfNoConfig] The Program node of the AST representing the code. This AST should be created from the text that BOM was stripped.
*/
constructor(textOrConfig, astIfNoConfig) {
let text, hasBOM, ast, parserServices, scopeManager, visitorKeys;
// Process overloading of arguments
if (typeof textOrConfig === "string") {
text = textOrConfig;
ast = astIfNoConfig;
hasBOM = false;
} else if (typeof textOrConfig === "object" && textOrConfig !== null) {
text = textOrConfig.text;
ast = textOrConfig.ast;
hasBOM = textOrConfig.hasBOM;
parserServices = textOrConfig.parserServices;
scopeManager = textOrConfig.scopeManager;
visitorKeys = textOrConfig.visitorKeys;
}
validate(ast);
super(ast.tokens, ast.comments);
/**
* General purpose caching for the class.
*/
this[caches] = new Map([
["scopes", new WeakMap()],
["vars", new Map()],
["configNodes", void 0]
]);
/**
* Indicates if the AST is ESTree compatible.
* @type {boolean}
*/
this.isESTree = ast.type === "Program";
/*
* Backwards compatibility for BOM handling.
*
* The `hasBOM` property has been available on the `SourceCode` object
* for a long time and is used to indicate if the source contains a BOM.
* The linter strips the BOM and just passes the `hasBOM` property to the
* `SourceCode` constructor to make it easier for languages to not deal with
* the BOM.
*
* However, the text passed in to the `SourceCode` constructor might still
* have a BOM if the constructor is called outside of the linter, so we still
* need to check for the BOM in the text.
*/
const textHasBOM = text.charCodeAt(0) === 0xFEFF;
/**
* The flag to indicate that the source code has Unicode BOM.
* @type {boolean}
*/
this.hasBOM = textHasBOM || !!hasBOM;
/**
* The original text source code.
* BOM was stripped from this text.
* @type {string}
*/
this.text = (textHasBOM ? text.slice(1) : text);
/**
* The parsed AST for the source code.
* @type {ASTNode}
*/
this.ast = ast;
/**
* The parser services of this source code.
* @type {Object}
*/
this.parserServices = parserServices || {};
/**
* The scope of this source code.
* @type {ScopeManager|null}
*/
this.scopeManager = scopeManager || null;
/**
* The visitor keys to traverse AST.
* @type {Object}
*/
this.visitorKeys = visitorKeys || Traverser.DEFAULT_VISITOR_KEYS;
// Check the source text for the presence of a shebang since it is parsed as a standard line comment.
const shebangMatched = this.text.match(astUtils.shebangPattern);
const hasShebang = shebangMatched && ast.comments.length && ast.comments[0].value === shebangMatched[1];
if (hasShebang) {
ast.comments[0].type = "Shebang";
}
this.tokensAndComments = sortedMerge(ast.tokens, ast.comments);
/**
* The source code split into lines according to ECMA-262 specification.
* This is done to avoid each rule needing to do so separately.
* @type {string[]}
*/
this.lines = [];
this.lineStartIndices = [0];
const lineEndingPattern = astUtils.createGlobalLinebreakMatcher();
let match;
/*
* Previously, this was implemented using a regex that
* matched a sequence of non-linebreak characters followed by a
* linebreak, then adding the lengths of the matches. However,
* this caused a catastrophic backtracking issue when the end
* of a file contained a large number of non-newline characters.
* To avoid this, the current implementation just matches newlines
* and uses match.index to get the correct line start indices.
*/
while ((match = lineEndingPattern.exec(this.text))) {
this.lines.push(this.text.slice(this.lineStartIndices.at(-1), match.index));
this.lineStartIndices.push(match.index + match[0].length);
}
this.lines.push(this.text.slice(this.lineStartIndices.at(-1)));
// don't allow further modification of this object
Object.freeze(this);
Object.freeze(this.lines);
}
/**
* Split the source code into multiple lines based on the line delimiters.
* @param {string} text Source code as a string.
* @returns {string[]} Array of source code lines.
* @public
*/
static splitLines(text) {
return text.split(astUtils.createGlobalLinebreakMatcher());
}
/**
* Gets the source code for the given node.
* @param {ASTNode} [node] The AST node to get the text for.
* @param {int} [beforeCount] The number of characters before the node to retrieve.
* @param {int} [afterCount] The number of characters after the node to retrieve.
* @returns {string} The text representing the AST node.
* @public
*/
getText(node, beforeCount, afterCount) {
if (node) {
return this.text.slice(Math.max(node.range[0] - (beforeCount || 0), 0),
node.range[1] + (afterCount || 0));
}
return this.text;
}
/**
* Gets the entire source text split into an array of lines.
* @returns {Array} The source text as an array of lines.
* @public
*/
getLines() {
return this.lines;
}
/**
* Retrieves an array containing all comments in the source code.
* @returns {ASTNode[]} An array of comment nodes.
* @public
*/
getAllComments() {
return this.ast.comments;
}
/**
* Retrieves the JSDoc comment for a given node.
* @param {ASTNode} node The AST node to get the comment for.
* @returns {Token|null} The Block comment token containing the JSDoc comment
* for the given node or null if not found.
* @public
* @deprecated
*/
getJSDocComment(node) {
/**
* Checks for the presence of a JSDoc comment for the given node and returns it.
* @param {ASTNode} astNode The AST node to get the comment for.
* @returns {Token|null} The Block comment token containing the JSDoc comment
* for the given node or null if not found.
* @private
*/
const findJSDocComment = astNode => {
const tokenBefore = this.getTokenBefore(astNode, { includeComments: true });
if (
tokenBefore &&
isCommentToken(tokenBefore) &&
tokenBefore.type === "Block" &&
tokenBefore.value.charAt(0) === "*" &&
astNode.loc.start.line - tokenBefore.loc.end.line <= 1
) {
return tokenBefore;
}
return null;
};
let parent = node.parent;
switch (node.type) {
case "ClassDeclaration":
case "FunctionDeclaration":
return findJSDocComment(looksLikeExport(parent) ? parent : node);
case "ClassExpression":
return findJSDocComment(parent.parent);
case "ArrowFunctionExpression":
case "FunctionExpression":
if (parent.type !== "CallExpression" && parent.type !== "NewExpression") {
while (
!this.getCommentsBefore(parent).length &&
!/Function/u.test(parent.type) &&
parent.type !== "MethodDefinition" &&
parent.type !== "Property"
) {
parent = parent.parent;
if (!parent) {
break;
}
}
if (parent && parent.type !== "FunctionDeclaration" && parent.type !== "Program") {
return findJSDocComment(parent);
}
}
return findJSDocComment(node);
// falls through
default:
return null;
}
}
/**
* Gets the deepest node containing a range index.
* @param {int} index Range index of the desired node.
* @returns {ASTNode} The node if found or null if not found.
* @public
*/
getNodeByRangeIndex(index) {
let result = null;
Traverser.traverse(this.ast, {
visitorKeys: this.visitorKeys,
enter(node) {
if (node.range[0] <= index && index < node.range[1]) {
result = node;
} else {
this.skip();
}
},
leave(node) {
if (node === result) {
this.break();
}
}
});
return result;
}
/**
* Determines if two nodes or tokens have at least one whitespace character
* between them. Order does not matter. Returns false if the given nodes or
* tokens overlap.
* @param {ASTNode|Token} first The first node or token to check between.
* @param {ASTNode|Token} second The second node or token to check between.
* @returns {boolean} True if there is a whitespace character between
* any of the tokens found between the two given nodes or tokens.
* @public
*/
isSpaceBetween(first, second) {
return isSpaceBetween(this, first, second, false);
}
/**
* Determines if two nodes or tokens have at least one whitespace character
* between them. Order does not matter. Returns false if the given nodes or
* tokens overlap.
* For backward compatibility, this method returns true if there are
* `JSXText` tokens that contain whitespaces between the two.
* @param {ASTNode|Token} first The first node or token to check between.
* @param {ASTNode|Token} second The second node or token to check between.
* @returns {boolean} True if there is a whitespace character between
* any of the tokens found between the two given nodes or tokens.
* @deprecated in favor of isSpaceBetween().
* @public
*/
isSpaceBetweenTokens(first, second) {
return isSpaceBetween(this, first, second, true);
}
/**
* Converts a source text index into a (line, column) pair.
* @param {number} index The index of a character in a file
* @throws {TypeError} If non-numeric index or index out of range.
* @returns {Object} A {line, column} location object with a 0-indexed column
* @public
*/
getLocFromIndex(index) {
if (typeof index !== "number") {
throw new TypeError("Expected `index` to be a number.");
}
if (index < 0 || index > this.text.length) {
throw new RangeError(`Index out of range (requested index ${index}, but source text has length ${this.text.length}).`);
}
/*
* For an argument of this.text.length, return the location one "spot" past the last character
* of the file. If the last character is a linebreak, the location will be column 0 of the next
* line; otherwise, the location will be in the next column on the same line.
*
* See getIndexFromLoc for the motivation for this special case.
*/
if (index === this.text.length) {
return { line: this.lines.length, column: this.lines.at(-1).length };
}
/*
* To figure out which line index is on, determine the last place at which index could
* be inserted into lineStartIndices to keep the list sorted.
*/
const lineNumber = index >= this.lineStartIndices.at(-1)
? this.lineStartIndices.length
: this.lineStartIndices.findIndex(el => index < el);
return { line: lineNumber, column: index - this.lineStartIndices[lineNumber - 1] };
}
/**
* Converts a (line, column) pair into a range index.
* @param {Object} loc A line/column location
* @param {number} loc.line The line number of the location (1-indexed)
* @param {number} loc.column The column number of the location (0-indexed)
* @throws {TypeError|RangeError} If `loc` is not an object with a numeric
* `line` and `column`, if the `line` is less than or equal to zero or
* the line or column is out of the expected range.
* @returns {number} The range index of the location in the file.
* @public
*/
getIndexFromLoc(loc) {
if (typeof loc !== "object" || typeof loc.line !== "number" || typeof loc.column !== "number") {
throw new TypeError("Expected `loc` to be an object with numeric `line` and `column` properties.");
}
if (loc.line <= 0) {
throw new RangeError(`Line number out of range (line ${loc.line} requested). Line numbers should be 1-based.`);
}
if (loc.line > this.lineStartIndices.length) {
throw new RangeError(`Line number out of range (line ${loc.line} requested, but only ${this.lineStartIndices.length} lines present).`);
}
const lineStartIndex = this.lineStartIndices[loc.line - 1];
const lineEndIndex = loc.line === this.lineStartIndices.length ? this.text.length : this.lineStartIndices[loc.line];
const positionIndex = lineStartIndex + loc.column;
/*
* By design, getIndexFromLoc({ line: lineNum, column: 0 }) should return the start index of
* the given line, provided that the line number is valid element of this.lines. Since the
* last element of this.lines is an empty string for files with trailing newlines, add a
* special case where getting the index for the first location after the end of the file
* will return the length of the file, rather than throwing an error. This allows rules to
* use getIndexFromLoc consistently without worrying about edge cases at the end of a file.
*/
if (
loc.line === this.lineStartIndices.length && positionIndex > lineEndIndex ||
loc.line < this.lineStartIndices.length && positionIndex >= lineEndIndex
) {
throw new RangeError(`Column number out of range (column ${loc.column} requested, but the length of line ${loc.line} is ${lineEndIndex - lineStartIndex}).`);
}
return positionIndex;
}
/**
* Gets the scope for the given node
* @param {ASTNode} currentNode The node to get the scope of
* @returns {Scope} The scope information for this node
* @throws {TypeError} If the `currentNode` argument is missing.
*/
getScope(currentNode) {
if (!currentNode) {
throw new TypeError("Missing required argument: node.");
}
// check cache first
const cache = this[caches].get("scopes");
const cachedScope = cache.get(currentNode);
if (cachedScope) {
return cachedScope;
}
// On Program node, get the outermost scope to avoid return Node.js special function scope or ES modules scope.
const inner = currentNode.type !== "Program";
for (let node = currentNode; node; node = node.parent) {
const scope = this.scopeManager.acquire(node, inner);
if (scope) {
if (scope.type === "function-expression-name") {
cache.set(currentNode, scope.childScopes[0]);
return scope.childScopes[0];
}
cache.set(currentNode, scope);
return scope;
}
}
cache.set(currentNode, this.scopeManager.scopes[0]);
return this.scopeManager.scopes[0];
}
/**
* Get the variables that `node` defines.
* This is a convenience method that passes through
* to the same method on the `scopeManager`.
* @param {ASTNode} node The node for which the variables are obtained.
* @returns {Array<Variable>} An array of variable nodes representing
* the variables that `node` defines.
*/
getDeclaredVariables(node) {
return this.scopeManager.getDeclaredVariables(node);
}
/* eslint-disable class-methods-use-this -- node is owned by SourceCode */
/**
* Gets all the ancestors of a given node
* @param {ASTNode} node The node
* @returns {Array<ASTNode>} All the ancestor nodes in the AST, not including the provided node, starting
* from the root node at index 0 and going inwards to the parent node.
* @throws {TypeError} When `node` is missing.
*/
getAncestors(node) {
if (!node) {
throw new TypeError("Missing required argument: node.");
}
const ancestorsStartingAtParent = [];
for (let ancestor = node.parent; ancestor; ancestor = ancestor.parent) {
ancestorsStartingAtParent.push(ancestor);
}
return ancestorsStartingAtParent.reverse();
}
/**
* Returns the location of the given node or token.
* @param {ASTNode|Token} nodeOrToken The node or token to get the location of.
* @returns {SourceLocation} The location of the node or token.
*/
getLoc(nodeOrToken) {
return nodeOrToken.loc;
}
/**
* Returns the range of the given node or token.
* @param {ASTNode|Token} nodeOrToken The node or token to get the range of.
* @returns {[number, number]} The range of the node or token.
*/
getRange(nodeOrToken) {
return nodeOrToken.range;
}
/* eslint-enable class-methods-use-this -- node is owned by SourceCode */
/**
* Marks a variable as used in the current scope
* @param {string} name The name of the variable to mark as used.
* @param {ASTNode} [refNode] The closest node to the variable reference.
* @returns {boolean} True if the variable was found and marked as used, false if not.
*/
markVariableAsUsed(name, refNode = this.ast) {
const currentScope = this.getScope(refNode);
let initialScope = currentScope;
/*
* When we are in an ESM or CommonJS module, we need to start searching
* from the top-level scope, not the global scope. For ESM the top-level
* scope is the module scope; for CommonJS the top-level scope is the
* outer function scope.
*
* Without this check, we might miss a variable declared with `var` at
* the top-level because it won't exist in the global scope.
*/
if (
currentScope.type === "global" &&
currentScope.childScopes.length > 0 &&
// top-level scopes refer to a `Program` node
currentScope.childScopes[0].block === this.ast
) {
initialScope = currentScope.childScopes[0];
}
for (let scope = initialScope; scope; scope = scope.upper) {
const variable = scope.variables.find(scopeVar => scopeVar.name === name);
if (variable) {
variable.eslintUsed = true;
return true;
}
}
return false;
}
/**
* Returns an array of all inline configuration nodes found in the
* source code.
* @returns {Array<Token>} An array of all inline configuration nodes.
*/
getInlineConfigNodes() {
// check the cache first
let configNodes = this[caches].get("configNodes");
if (configNodes) {
return configNodes;
}
// calculate fresh config nodes
configNodes = this.ast.comments.filter(comment => {
// shebang comments are never directives
if (comment.type === "Shebang") {
return false;
}
const directive = commentParser.parseDirective(comment.value);
if (!directive) {
return false;
}
if (!directivesPattern.test(directive.label)) {
return false;
}
// only certain comment types are supported as line comments
return comment.type !== "Line" || !!/^eslint-disable-(next-)?line$/u.test(directive.label);
});
this[caches].set("configNodes", configNodes);
return configNodes;
}
/**
* Returns an all directive nodes that enable or disable rules along with any problems
* encountered while parsing the directives.
* @returns {{problems:Array<Problem>,directives:Array<Directive>}} Information
* that ESLint needs to further process the directives.
*/
getDisableDirectives() {
// check the cache first
const cachedDirectives = this[caches].get("disableDirectives");
if (cachedDirectives) {
return cachedDirectives;
}
const problems = [];
const directives = [];
this.getInlineConfigNodes().forEach(comment => {
// Step 1: Parse the directive
const {
label,
value,
justification: justificationPart
} = commentParser.parseDirective(comment.value);
// Step 2: Extract the directive value
const lineCommentSupported = /^eslint-disable-(next-)?line$/u.test(label);
if (comment.type === "Line" && !lineCommentSupported) {
return;
}
// Step 3: Validate the directive does not span multiple lines
if (label === "eslint-disable-line" && comment.loc.start.line !== comment.loc.end.line) {
const message = `${label} comment should not span multiple lines.`;
problems.push({
ruleId: null,
message,
loc: comment.loc
});
return;
}
// Step 4: Extract the directive value and create the Directive object
switch (label) {
case "eslint-disable":
case "eslint-enable":
case "eslint-disable-next-line":
case "eslint-disable-line": {
const directiveType = label.slice("eslint-".length);
directives.push(new Directive({
type: directiveType,
node: comment,
value,
justification: justificationPart
}));
}
// no default
}
});
const result = { problems, directives };
this[caches].set("disableDirectives", result);
return result;
}
/**
* Applies language options sent in from the core.
* @param {Object} languageOptions The language options for this run.
* @returns {void}
*/
applyLanguageOptions(languageOptions) {
/*
* Add configured globals and language globals
*
* Using Object.assign instead of object spread for performance reasons
* https://github.com/eslint/eslint/issues/16302
*/
const configGlobals = Object.assign(
Object.create(null), // https://github.com/eslint/eslint/issues/18363
getGlobalsForEcmaVersion(languageOptions.ecmaVersion),
languageOptions.sourceType === "commonjs" ? globals.commonjs : void 0,
languageOptions.globals
);
const varsCache = this[caches].get("vars");
varsCache.set("configGlobals", configGlobals);
}
/**
* Applies configuration found inside of the source code. This method is only
* called when ESLint is running with inline configuration allowed.
* @returns {{problems:Array<Problem>,configs:{config:FlatConfigArray,loc:Location}}} Information
* that ESLint needs to further process the inline configuration.
*/
applyInlineConfig() {
const problems = [];
const configs = [];
const exportedVariables = {};
const inlineGlobals = Object.create(null);
this.getInlineConfigNodes().forEach(comment => {
const { label, value } = commentParser.parseDirective(comment.value);
switch (label) {
case "exported":
Object.assign(exportedVariables, commentParser.parseListConfig(value));
break;
case "globals":
case "global":
for (const [id, idSetting] of Object.entries(commentParser.parseStringConfig(value))) {
let normalizedValue;
try {
normalizedValue = normalizeConfigGlobal(idSetting);
} catch (err) {
problems.push({
ruleId: null,
loc: comment.loc,
message: err.message
});
continue;
}
if (inlineGlobals[id]) {
inlineGlobals[id].comments.push(comment);
inlineGlobals[id].value = normalizedValue;
} else {
inlineGlobals[id] = {
comments: [comment],
value: normalizedValue
};
}
}
break;
case "eslint": {
const parseResult = commentParser.parseJSONLikeConfig(value);
if (parseResult.ok) {
configs.push({
config: {
rules: parseResult.config
},
loc: comment.loc
});
} else {
problems.push({
ruleId: null,
loc: comment.loc,
message: parseResult.error.message
});
}
break;
}
// no default
}
});
// save all the new variables for later
const varsCache = this[caches].get("vars");
varsCache.set("inlineGlobals", inlineGlobals);
varsCache.set("exportedVariables", exportedVariables);
return {
configs,
problems
};
}
/**
* Called by ESLint core to indicate that it has finished providing
* information. We now add in all the missing variables and ensure that
* state-changing methods cannot be called by rules.
* @returns {void}
*/
finalize() {
const varsCache = this[caches].get("vars");
const configGlobals = varsCache.get("configGlobals");
const inlineGlobals = varsCache.get("inlineGlobals");
const exportedVariables = varsCache.get("exportedVariables");
const globalScope = this.scopeManager.scopes[0];
addDeclaredGlobals(globalScope, configGlobals, inlineGlobals);
if (exportedVariables) {
markExportedVariables(globalScope, exportedVariables);
}
}
/**
* Traverse the source code and return the steps that were taken.
* @returns {Array<TraversalStep>} The steps that were taken while traversing the source code.
*/
traverse() {
// Because the AST doesn't mutate, we can cache the steps
if (this.#steps) {
return this.#steps;
}
const steps = this.#steps = [];
/*
* This logic works for any AST, not just ESTree. Because ESLint has allowed
* custom parsers to return any AST, we need to ensure that the traversal
* logic works for any AST.
*/
const emitter = createEmitter();
let analyzer = {
enterNode(node) {
steps.push(new VisitNodeStep({
target: node,
phase: 1,
args: [node, node.parent]
}));
},
leaveNode(node) {
steps.push(new VisitNodeStep({
target: node,
phase: 2,
args: [node, node.parent]
}));
},
emitter
};
/*
* We do code path analysis for ESTree only. Code path analysis is not
* necessary for other ASTs, and it's also not possible to do for other
* ASTs because the necessary information is not available.
*
* Generally speaking, we can tell that the AST is an ESTree if it has a
* Program node at the top level. This is not a perfect heuristic, but it
* is good enough for now.
*/
if (this.isESTree) {
analyzer = new CodePathAnalyzer(analyzer);
CODE_PATH_EVENTS.forEach(eventName => {
emitter.on(eventName, (...args) => {
steps.push(new CallMethodStep({
target: eventName,
args
}));
});
});
}
/*
* The actual AST traversal is done by the `Traverser` class. This class
* is responsible for walking the AST and calling the appropriate methods
* on the `analyzer` object, which is appropriate for the given AST.
*/
Traverser.traverse(this.ast, {
enter(node, parent) {
// save the parent node on a property for backwards compatibility
node.parent = parent;
analyzer.enterNode(node);
},
leave(node) {
analyzer.leaveNode(node);
},
visitorKeys: this.visitorKeys
});
return steps;
}
}
module.exports = SourceCode;