/* eslint-disable no-param-reassign*/ import TokenTranslator from "./token-translator.js"; import { normalizeOptions } from "./options.js"; const STATE = Symbol("espree's internal state"); const ESPRIMA_FINISH_NODE = Symbol("espree's esprimaFinishNode"); /** * Converts an Acorn comment to a Esprima comment. * @param {boolean} block True if it's a block comment, false if not. * @param {string} text The text of the comment. * @param {int} start The index at which the comment starts. * @param {int} end The index at which the comment ends. * @param {Location} startLoc The location at which the comment starts. * @param {Location} endLoc The location at which the comment ends. * @param {string} code The source code being parsed. * @returns {Object} The comment object. * @private */ function convertAcornCommentToEsprimaComment(block, text, start, end, startLoc, endLoc, code) { let type; if (block) { type = "Block"; } else if (code.slice(start, start + 2) === "#!") { type = "Hashbang"; } else { type = "Line"; } const comment = { type, value: text }; if (typeof start === "number") { comment.start = start; comment.end = end; comment.range = [start, end]; } if (typeof startLoc === "object") { comment.loc = { start: startLoc, end: endLoc }; } return comment; } export default () => Parser => { const tokTypes = Object.assign({}, Parser.acorn.tokTypes); if (Parser.acornJsx) { Object.assign(tokTypes, Parser.acornJsx.tokTypes); } return class Espree extends Parser { constructor(opts, code) { if (typeof opts !== "object" || opts === null) { opts = {}; } if (typeof code !== "string" && !(code instanceof String)) { code = String(code); } // save original source type in case of commonjs const originalSourceType = opts.sourceType; const options = normalizeOptions(opts); const ecmaFeatures = options.ecmaFeatures || {}; const tokenTranslator = options.tokens === true ? new TokenTranslator(tokTypes, code) : null; /* * Data that is unique to Espree and is not represented internally * in Acorn. * * For ES2023 hashbangs, Espree will call `onComment()` during the * constructor, so we must define state before having access to * `this`. */ const state = { originalSourceType: originalSourceType || options.sourceType, tokens: tokenTranslator ? [] : null, comments: options.comment === true ? [] : null, impliedStrict: ecmaFeatures.impliedStrict === true && options.ecmaVersion >= 5, ecmaVersion: options.ecmaVersion, jsxAttrValueToken: false, lastToken: null, templateElements: [] }; // Initialize acorn parser. super({ // do not use spread, because we don't want to pass any unknown options to acorn ecmaVersion: options.ecmaVersion, sourceType: options.sourceType, ranges: options.ranges, locations: options.locations, allowReserved: options.allowReserved, // Truthy value is true for backward compatibility. allowReturnOutsideFunction: options.allowReturnOutsideFunction, // Collect tokens onToken: token => { if (tokenTranslator) { // Use `tokens`, `ecmaVersion`, and `jsxAttrValueToken` in the state. tokenTranslator.onToken(token, state); } if (token.type !== tokTypes.eof) { state.lastToken = token; } }, // Collect comments onComment: (block, text, start, end, startLoc, endLoc) => { if (state.comments) { const comment = convertAcornCommentToEsprimaComment(block, text, start, end, startLoc, endLoc, code); state.comments.push(comment); } } }, code); /* * We put all of this data into a symbol property as a way to avoid * potential naming conflicts with future versions of Acorn. */ this[STATE] = state; } tokenize() { do { this.next(); } while (this.type !== tokTypes.eof); // Consume the final eof token this.next(); const extra = this[STATE]; const tokens = extra.tokens; if (extra.comments) { tokens.comments = extra.comments; } return tokens; } finishNode(...args) { const result = super.finishNode(...args); return this[ESPRIMA_FINISH_NODE](result); } finishNodeAt(...args) { const result = super.finishNodeAt(...args); return this[ESPRIMA_FINISH_NODE](result); } parse() { const extra = this[STATE]; const program = super.parse(); program.sourceType = extra.originalSourceType; if (extra.comments) { program.comments = extra.comments; } if (extra.tokens) { program.tokens = extra.tokens; } /* * Adjust opening and closing position of program to match Esprima. * Acorn always starts programs at range 0 whereas Esprima starts at the * first AST node's start (the only real difference is when there's leading * whitespace or leading comments). Acorn also counts trailing whitespace * as part of the program whereas Esprima only counts up to the last token. */ if (program.body.length) { const [firstNode] = program.body; if (program.range) { program.range[0] = firstNode.range[0]; } if (program.loc) { program.loc.start = firstNode.loc.start; } program.start = firstNode.start; } if (extra.lastToken) { if (program.range) { program.range[1] = extra.lastToken.range[1]; } if (program.loc) { program.loc.end = extra.lastToken.loc.end; } program.end = extra.lastToken.end; } /* * https://github.com/eslint/espree/issues/349 * Ensure that template elements have correct range information. * This is one location where Acorn produces a different value * for its start and end properties vs. the values present in the * range property. In order to avoid confusion, we set the start * and end properties to the values that are present in range. * This is done here, instead of in finishNode(), because Acorn * uses the values of start and end internally while parsing, making * it dangerous to change those values while parsing is ongoing. * By waiting until the end of parsing, we can safely change these * values without affect any other part of the process. */ this[STATE].templateElements.forEach(templateElement => { const startOffset = -1; const endOffset = templateElement.tail ? 1 : 2; templateElement.start += startOffset; templateElement.end += endOffset; if (templateElement.range) { templateElement.range[0] += startOffset; templateElement.range[1] += endOffset; } if (templateElement.loc) { templateElement.loc.start.column += startOffset; templateElement.loc.end.column += endOffset; } }); return program; } parseTopLevel(node) { if (this[STATE].impliedStrict) { this.strict = true; } return super.parseTopLevel(node); } /** * Overwrites the default raise method to throw Esprima-style errors. * @param {int} pos The position of the error. * @param {string} message The error message. * @throws {SyntaxError} A syntax error. * @returns {void} */ raise(pos, message) { const loc = Parser.acorn.getLineInfo(this.input, pos); const err = new SyntaxError(message); err.index = pos; err.lineNumber = loc.line; err.column = loc.column + 1; // acorn uses 0-based columns throw err; } /** * Overwrites the default raise method to throw Esprima-style errors. * @param {int} pos The position of the error. * @param {string} message The error message. * @throws {SyntaxError} A syntax error. * @returns {void} */ raiseRecoverable(pos, message) { this.raise(pos, message); } /** * Overwrites the default unexpected method to throw Esprima-style errors. * @param {int} pos The position of the error. * @throws {SyntaxError} A syntax error. * @returns {void} */ unexpected(pos) { let message = "Unexpected token"; if (pos !== null && pos !== void 0) { this.pos = pos; if (this.options.locations) { while (this.pos < this.lineStart) { this.lineStart = this.input.lastIndexOf("\n", this.lineStart - 2) + 1; --this.curLine; } } this.nextToken(); } if (this.end > this.start) { message += ` ${this.input.slice(this.start, this.end)}`; } this.raise(this.start, message); } /* * Esprima-FB represents JSX strings as tokens called "JSXText", but Acorn-JSX * uses regular tt.string without any distinction between this and regular JS * strings. As such, we intercept an attempt to read a JSX string and set a flag * on extra so that when tokens are converted, the next token will be switched * to JSXText via onToken. */ jsx_readString(quote) { // eslint-disable-line camelcase const result = super.jsx_readString(quote); if (this.type === tokTypes.string) { this[STATE].jsxAttrValueToken = true; } return result; } /** * Performs last-minute Esprima-specific compatibility checks and fixes. * @param {ASTNode} result The node to check. * @returns {ASTNode} The finished node. */ [ESPRIMA_FINISH_NODE](result) { // Acorn doesn't count the opening and closing backticks as part of templates // so we have to adjust ranges/locations appropriately. if (result.type === "TemplateElement") { // save template element references to fix start/end later this[STATE].templateElements.push(result); } if (result.type.includes("Function") && !result.generator) { result.generator = false; } return result; } }; };