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'use strict';
/* Derived from normalize-url https://github.com/sindresorhus/normalize-url/main/index.js by Sindre Sorhus */
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs
const DATA_URL_DEFAULT_MIME_TYPE = 'text/plain';
const DATA_URL_DEFAULT_CHARSET = 'us-ascii';
const supportedProtocols = new Set(['https:', 'http:', 'file:']);
/**
* @param {string} urlString
* @return {boolean} */
function hasCustomProtocol(urlString) {
try {
const { protocol } = new URL(urlString);
return protocol.endsWith(':') && !supportedProtocols.has(protocol);
} catch {
return false;
}
}
/**
* @param {string} urlString
* @return {string} */
function normalizeDataURL(urlString) {
const match = /^data:(?<type>[^,]*?),(?<data>[^#]*?)(?:#(?<hash>.*))?$/.exec(
urlString
);
if (!match) {
throw new Error(`Invalid URL: ${urlString}`);
}
let { type, data, hash } =
/** @type {{type: string, data: string, hash: string}} */ (match.groups);
const mediaType = type.split(';');
let isBase64 = false;
if (mediaType[mediaType.length - 1] === 'base64') {
mediaType.pop();
isBase64 = true;
}
// Lowercase MIME type
const mimeType = mediaType.shift()?.toLowerCase() ?? '';
const attributes = mediaType
.map(
/** @type {(string: string) => string} */ (attribute) => {
let [key, value = ''] = attribute
.split('=')
.map(
/** @type {(string: string) => string} */ (string) => string.trim()
);
// Lowercase `charset`
if (key === 'charset') {
value = value.toLowerCase();
if (value === DATA_URL_DEFAULT_CHARSET) {
return '';
}
}
return `${key}${value ? `=${value}` : ''}`;
}
)
.filter(Boolean);
const normalizedMediaType = [...attributes];
if (isBase64) {
normalizedMediaType.push('base64');
}
if (
normalizedMediaType.length > 0 ||
(mimeType && mimeType !== DATA_URL_DEFAULT_MIME_TYPE)
) {
normalizedMediaType.unshift(mimeType);
}
return `data:${normalizedMediaType.join(';')},${
isBase64 ? data.trim() : data
}${hash ? `#${hash}` : ''}`;
}
/**
* @param {string} urlString
* @return {string}
*/
function normalizeUrl(urlString) {
urlString = urlString.trim();
// Data URL
if (/^data:/i.test(urlString)) {
return normalizeDataURL(urlString);
}
if (hasCustomProtocol(urlString)) {
return urlString;
}
const hasRelativeProtocol = urlString.startsWith('//');
const isRelativeUrl = !hasRelativeProtocol && /^\.*\//.test(urlString);
// Prepend protocol
if (!isRelativeUrl) {
urlString = urlString.replace(/^(?!(?:\w+:)?\/\/)|^\/\//, 'http:');
}
const urlObject = new URL(urlString);
// Remove duplicate slashes if not preceded by a protocol
if (urlObject.pathname) {
urlObject.pathname = urlObject.pathname.replace(
/(?<!\b[a-z][a-z\d+\-.]{1,50}:)\/{2,}/g,
'/'
);
}
// Decode URI octets
if (urlObject.pathname) {
try {
urlObject.pathname = decodeURI(urlObject.pathname);
} catch {
/* Do nothing */
}
}
if (urlObject.hostname) {
// Remove trailing dot
urlObject.hostname = urlObject.hostname.replace(/\.$/, '');
}
urlObject.pathname = urlObject.pathname.replace(/\/$/, '');
// Take advantage of many of the Node `url` normalizations
urlString = urlObject.toString();
// Remove ending `/`
if (urlObject.pathname === '/' && urlObject.hash === '') {
urlString = urlString.replace(/\/$/, '');
}
// Restore relative protocol
if (hasRelativeProtocol) {
urlString = urlString.replace(/^http:\/\//, '//');
}
return urlString;
}
module.exports = normalizeUrl;
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