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/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Ivan Kopeykin @vankop
*/
"use strict";
/** @typedef {import("./fs").InputFileSystem} InputFileSystem */
/** @typedef {(error: Error|null, result?: Buffer) => void} ErrorFirstCallback */
const backSlashCharCode = "\\".charCodeAt(0);
const slashCharCode = "/".charCodeAt(0);
const aLowerCaseCharCode = "a".charCodeAt(0);
const zLowerCaseCharCode = "z".charCodeAt(0);
const aUpperCaseCharCode = "A".charCodeAt(0);
const zUpperCaseCharCode = "Z".charCodeAt(0);
const _0CharCode = "0".charCodeAt(0);
const _9CharCode = "9".charCodeAt(0);
const plusCharCode = "+".charCodeAt(0);
const hyphenCharCode = "-".charCodeAt(0);
const colonCharCode = ":".charCodeAt(0);
const hashCharCode = "#".charCodeAt(0);
const queryCharCode = "?".charCodeAt(0);
/**
* Get scheme if specifier is an absolute URL specifier
* e.g. Absolute specifiers like 'file:///user/webpack/index.js'
* https://tools.ietf.org/html/rfc3986#section-3.1
* @param {string} specifier specifier
* @returns {string|undefined} scheme if absolute URL specifier provided
*/
function getScheme(specifier) {
const start = specifier.charCodeAt(0);
// First char maybe only a letter
if (
(start < aLowerCaseCharCode || start > zLowerCaseCharCode) &&
(start < aUpperCaseCharCode || start > zUpperCaseCharCode)
) {
return undefined;
}
let i = 1;
let ch = specifier.charCodeAt(i);
while (
(ch >= aLowerCaseCharCode && ch <= zLowerCaseCharCode) ||
(ch >= aUpperCaseCharCode && ch <= zUpperCaseCharCode) ||
(ch >= _0CharCode && ch <= _9CharCode) ||
ch === plusCharCode ||
ch === hyphenCharCode
) {
if (++i === specifier.length) return undefined;
ch = specifier.charCodeAt(i);
}
// Scheme must end with colon
if (ch !== colonCharCode) return undefined;
// Check for Windows absolute path
// https://url.spec.whatwg.org/#url-miscellaneous
if (i === 1) {
const nextChar = i + 1 < specifier.length ? specifier.charCodeAt(i + 1) : 0;
if (
nextChar === 0 ||
nextChar === backSlashCharCode ||
nextChar === slashCharCode ||
nextChar === hashCharCode ||
nextChar === queryCharCode
) {
return undefined;
}
}
return specifier.slice(0, i).toLowerCase();
}
/**
* @param {string} specifier specifier
* @returns {string|null} protocol if absolute URL specifier provided
*/
function getProtocol(specifier) {
const scheme = getScheme(specifier);
return scheme === undefined ? undefined : scheme + ":";
}
exports.getScheme = getScheme;
exports.getProtocol = getProtocol;