Files
routie/frontend/node_modules/enhanced-resolve/lib/util/identifier.js
T

104 lines
2.8 KiB
JavaScript

/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Ivan Kopeykin @vankop
*/
"use strict";
const memorize = require("./memoize");
const getUrl = memorize(() => require("url"));
const PATH_QUERY_FRAGMENT_REGEXP =
/^(#?(?:\0.|[^?#\0])*)(\?(?:\0.|[^#\0])*)?(#.*)?$/;
const ZERO_ESCAPE_REGEXP = /\0(.)/g;
const FILE_REG_EXP = /file:/i;
/**
* Index past a DOS device path prefix (`\\?\…` or `\\.\…`), or 0. Kept
* out of `parseIdentifier` on purpose: inlining it back bloats the caller
* beyond the size where V8's interpreter and JIT both handle it well
* (the cause of the description-files-multi CodSpeed regression).
* @param {string} identifier identifier known to start with `\`
* @returns {number} 4 if identifier starts with a DOS device prefix, else 0
*/
function dosPrefixEnd(identifier) {
if (
identifier.length >= 4 &&
identifier.charCodeAt(1) === 92 &&
identifier.charCodeAt(3) === 92
) {
const c2 = identifier.charCodeAt(2);
if (c2 === 63 || c2 === 46) return 4;
}
return 0;
}
/**
* @param {string} identifier identifier
* @returns {[string, string, string] | null} parsed identifier
*/
function parseIdentifier(identifier) {
if (!identifier) {
return null;
}
if (FILE_REG_EXP.test(identifier)) {
identifier = getUrl().fileURLToPath(identifier);
}
const firstEscape = identifier.indexOf("\0");
// Handle `\0`
if (firstEscape !== -1) {
const match = PATH_QUERY_FRAGMENT_REGEXP.exec(identifier);
if (!match) return null;
return [
match[1].replace(ZERO_ESCAPE_REGEXP, "$1"),
match[2] ? match[2].replace(ZERO_ESCAPE_REGEXP, "$1") : "",
match[3] || "",
];
}
// Fast path for inputs that don't use \0 escaping. DOS device paths
// (`\\?\…`, `\\.\…`) embed a literal `?` / `.` that must not be read
// as a query separator; skip past the prefix when the input actually
// starts with `\`. Gate is a single char-code compare so this function
// stays inside V8's inline budget for its hot callers (resolver parse).
const scanStart =
identifier.charCodeAt(0) === 92 ? dosPrefixEnd(identifier) : 0;
const queryStart = identifier.indexOf("?", scanStart);
// Start at index 1 (or past a DOS prefix) to ignore a possible leading hash.
const fragmentStart = identifier.indexOf("#", scanStart || 1);
if (fragmentStart < 0) {
if (queryStart < 0) {
// No fragment, no query
return [identifier, "", ""];
}
// Query, no fragment
return [identifier.slice(0, queryStart), identifier.slice(queryStart), ""];
}
if (queryStart < 0 || fragmentStart < queryStart) {
// Fragment, no query
return [
identifier.slice(0, fragmentStart),
"",
identifier.slice(fragmentStart),
];
}
// Query and fragment
return [
identifier.slice(0, queryStart),
identifier.slice(queryStart, fragmentStart),
identifier.slice(fragmentStart),
];
}
module.exports.parseIdentifier = parseIdentifier;