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