/* eslint no-param-reassign: 0 -- stylistic choice */
import TokenTranslator from "./token-translator.js";
import { normalizeOptions } from "./options.js";
/**
* @import {
* CommentType,
* EspreeParserCtor,
* EsprimaNode,
* AcornJsxParserCtorEnhanced,
* TokTypes
* } from "./types.js";
* @import {
* Options,
* EspreeToken as EsprimaToken,
* EspreeTokens as EsprimaTokens,
* EspreeComment as EsprimaComment
* } from "../espree.js";
* @import { NormalizedEcmaVersion } from "./options.js";
* @import * as acorn from "acorn";
*/
/**
* @typedef {{
* originalSourceType: "script" | "module" | "commonjs" | undefined
* tokens: EsprimaToken[] | null,
* comments: EsprimaComment[] | null,
* impliedStrict: boolean,
* ecmaVersion: NormalizedEcmaVersion,
* jsxAttrValueToken: boolean,
* lastToken: acorn.Token | null,
* templateElements: acorn.TemplateElement[]
* }} State
*/
/**
* @typedef {{
* sourceType?: "script"|"module"|"commonjs";
* comments?: EsprimaComment[];
* tokens?: EsprimaToken[];
* body: acorn.Node[];
* } & acorn.Program} EsprimaProgramNode
*/
// ----------------------------------------------------------------------------
// Types exported from file
// ----------------------------------------------------------------------------
/**
* @typedef {{
* index?: number;
* lineNumber?: number;
* column?: number;
* } & SyntaxError} EnhancedSyntaxError
*/
// We add `jsxAttrValueToken` ourselves.
/**
* @typedef {{
* jsxAttrValueToken?: acorn.TokenType;
* } & TokTypes} EnhancedTokTypes
*/
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 {number} start The index at which the comment starts.
* @param {number} end The index at which the comment ends.
* @param {acorn.Position | undefined} startLoc The location at which the comment starts.
* @param {acorn.Position | undefined} endLoc The location at which the comment ends.
* @param {string} code The source code being parsed.
* @returns {EsprimaComment} The comment object.
* @private
*/
function convertAcornCommentToEsprimaComment(
block,
text,
start,
end,
startLoc,
endLoc,
code,
) {
/** @type {CommentType} */
let type;
if (block) {
type = "Block";
} else if (code.slice(start, start + 2) === "#!") {
type = "Hashbang";
} else {
type = "Line";
}
/**
* @type {{
* type: CommentType,
* value: string,
* start?: number,
* end?: number,
* range?: [number, number],
* loc?: {
* start: acorn.Position | undefined,
* end: acorn.Position | undefined
* }
* }}
*/
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;
}
// eslint-disable-next-line arrow-body-style -- For TS
export default () => {
/**
* Returns the Espree parser.
* @param {AcornJsxParserCtorEnhanced} Parser The Acorn parser. The `acorn` property is missing from acorn's
* TypeScript but is present statically on the class.
* @returns {EspreeParserCtor} The Espree Parser constructor.
*/
return Parser => {
const tokTypes = /** @type {EnhancedTokTypes} */ (
Object.assign({}, Parser.acorn.tokTypes)
);
if (Parser.acornJsx) {
Object.assign(tokTypes, Parser.acornJsx.tokTypes);
}
return class Espree extends Parser {
/**
* @param {Options | null | undefined} opts The parser options
* @param {string | object} code The code which will be converted to a string.
*/
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,
// @ts-expect-error Appears to be a TS bug since the type is indeed string|String
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`.
* @type {State}
*/
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,
/**
* @type {Omit<State, "tokens"> & {
* tokens: EsprimaToken[]
* }}
*/
(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,
// @ts-expect-error Appears to be a TS bug
// since the type is indeed string|String
code,
);
state.comments.push(comment);
}
},
},
// @ts-expect-error Appears to be a TS bug
// since the type is indeed string|String
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;
}
/**
* Returns Espree tokens.
* @returns {EsprimaTokens} The Esprima-compatible tokens
*/
tokenize() {
do {
this.next();
} while (this.type !== tokTypes.eof);
// Consume the final eof token
this.next();
const extra = this[STATE];
const tokens = /** @type {EsprimaTokens} */ (extra.tokens);
if (extra.comments) {
tokens.comments = extra.comments;
}
return tokens;
}
/**
* Calls parent.
* @param {acorn.Node} node The node
* @param {string} type The type
* @returns {acorn.Node} The altered Node
*/
finishNode(node, type) {
const result = super.finishNode(node, type);
return this[ESPRIMA_FINISH_NODE](result);
}
/**
* Calls parent.
* @param {acorn.Node} node The node
* @param {string} type The type
* @param {number} pos The position
* @param {acorn.Position} loc The location
* @returns {acorn.Node} The altered Node
*/
finishNodeAt(node, type, pos, loc) {
const result = super.finishNodeAt(node, type, pos, loc);
return this[ESPRIMA_FINISH_NODE](result);
}
/**
* Parses.
* @returns {EsprimaProgramNode} The program Node
*/
parse() {
const extra = this[STATE];
const prog = super.parse();
const program = /** @type {EsprimaProgramNode} */ (prog);
// @ts-expect-error TS bug? We've already converted to `EsprimaProgramNode`
program.sourceType = extra.originalSourceType;
if (extra.comments) {
program.comments = extra.comments;
}
if (extra.tokens) {
program.tokens = extra.tokens;
}
/*
* 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;
}
/**
* Parses top level.
* @param {acorn.Node} node AST Node
* @returns {acorn.Node} The changed node
*/
parseTopLevel(node) {
if (this[STATE].impliedStrict) {
this.strict = true;
}
return super.parseTopLevel(node);
}
/**
* Overwrites the default raise method to throw Esprima-style errors.
* @param {number} pos The position of the error.
* @param {string} message The error message.
* @throws {EnhancedSyntaxError} A syntax error.
* @returns {void}
*/
raise(pos, message) {
const loc = Parser.acorn.getLineInfo(this.input, pos);
const err = /** @type {EnhancedSyntaxError} */ (
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 {number} 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 {number} 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.
* @param {number} quote A character code
* @returns {void}
*/ // eslint-disable-next-line camelcase -- required by API
jsx_readString(quote) {
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 {acorn.Node} result The node to check.
* @returns {EsprimaNode} 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(
/** @type {acorn.TemplateElement} */
(result),
);
}
if (
result.type.includes("Function") &&
!("generator" in result)
) {
/**
* @type {acorn.FunctionDeclaration|acorn.FunctionExpression|
* acorn.ArrowFunctionExpression}
*/
(result).generator = false;
}
return result;
}
};
};
};