Current File : /var/www/html/node_modules/eslint/lib/source-code/source-code.js
/**
* @fileoverview Abstraction of JavaScript source code.
* @author Nicholas C. Zakas
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const
{ isCommentToken } = require("eslint-utils"),
TokenStore = require("./token-store"),
astUtils = require("../shared/ast-utils"),
Traverser = require("../shared/traverser");
//------------------------------------------------------------------------------
// Private
//------------------------------------------------------------------------------
/**
* 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");
}
}
/**
* 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;
}
/**
* 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;
}
//------------------------------------------------------------------------------
// Public Interface
//------------------------------------------------------------------------------
/**
* Represents parsed source code.
*/
class SourceCode extends TokenStore {
/**
* @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 {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, ast, parserServices, scopeManager, visitorKeys;
// Process overloading.
if (typeof textOrConfig === "string") {
text = textOrConfig;
ast = astIfNoConfig;
} else if (typeof textOrConfig === "object" && textOrConfig !== null) {
text = textOrConfig.text;
ast = textOrConfig.ast;
parserServices = textOrConfig.parserServices;
scopeManager = textOrConfig.scopeManager;
visitorKeys = textOrConfig.visitorKeys;
}
validate(ast);
super(ast.tokens, ast.comments);
/**
* The flag to indicate that the source code has Unicode BOM.
* @type {boolean}
*/
this.hasBOM = (text.charCodeAt(0) === 0xFEFF);
/**
* The original text source code.
* BOM was stripped from this text.
* @type {string}
*/
this.text = (this.hasBOM ? 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[this.lineStartIndices.length - 1], match.index));
this.lineStartIndices.push(match.index + match[0].length);
}
this.lines.push(this.text.slice(this.lineStartIndices[this.lineStartIndices.length - 1]));
// Cache for comments found using getComments().
this._commentCache = new WeakMap();
// don't allow 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;
}
/**
* Gets all comments for the given node.
* @param {ASTNode} node The AST node to get the comments for.
* @returns {Object} An object containing a leading and trailing array
* of comments indexed by their position.
* @public
* @deprecated replaced by getCommentsBefore(), getCommentsAfter(), and getCommentsInside().
*/
getComments(node) {
if (this._commentCache.has(node)) {
return this._commentCache.get(node);
}
const comments = {
leading: [],
trailing: []
};
/*
* Return all comments as leading comments of the Program node when
* there is no executable code.
*/
if (node.type === "Program") {
if (node.body.length === 0) {
comments.leading = node.comments;
}
} else {
/*
* Return comments as trailing comments of nodes that only contain
* comments (to mimic the comment attachment behavior present in Espree).
*/
if ((node.type === "BlockStatement" || node.type === "ClassBody") && node.body.length === 0 ||
node.type === "ObjectExpression" && node.properties.length === 0 ||
node.type === "ArrayExpression" && node.elements.length === 0 ||
node.type === "SwitchStatement" && node.cases.length === 0
) {
comments.trailing = this.getTokens(node, {
includeComments: true,
filter: isCommentToken
});
}
/*
* Iterate over tokens before and after node and collect comment tokens.
* Do not include comments that exist outside of the parent node
* to avoid duplication.
*/
let currentToken = this.getTokenBefore(node, { includeComments: true });
while (currentToken && isCommentToken(currentToken)) {
if (node.parent && node.parent.type !== "Program" && (currentToken.start < node.parent.start)) {
break;
}
comments.leading.push(currentToken);
currentToken = this.getTokenBefore(currentToken, { includeComments: true });
}
comments.leading.reverse();
currentToken = this.getTokenAfter(node, { includeComments: true });
while (currentToken && isCommentToken(currentToken)) {
if (node.parent && node.parent.type !== "Program" && (currentToken.end > node.parent.end)) {
break;
}
comments.trailing.push(currentToken);
currentToken = this.getTokenAfter(currentToken, { includeComments: true });
}
}
this._commentCache.set(node, comments);
return 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[this.lines.length - 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[this.lineStartIndices.length - 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;
}
}
module.exports = SourceCode;
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