chore: import upstream snapshot with attribution

packages/workers-shared/utils/configuration/validateURL.ts

@@ -0,0 +1,76 @@
+export const extractPathname = (
+	path = "/",
+	includeSearch: boolean,
+	includeHash: boolean
+): string => {
+	if (!path.startsWith("/")) {
+		path = `/${path}`;
+	}
+	const url = new URL(`//${path}`, "relative://");
+	return `${url.pathname}${includeSearch ? url.search : ""}${
+		includeHash ? url.hash : ""
+	}`;
+};
+
+const URL_REGEX = /^https:\/\/+(?<host>[^/]+)\/?(?<path>.*)/;
+const HOST_WITH_PORT_REGEX = /.*:\d+$/;
+const PATH_REGEX = /^\//;
+
+export const validateUrl = (
+	token: string,
+	onlyRelative = false,
+	disallowPorts = false,
+	includeSearch = false,
+	includeHash = false
+): [undefined, string] | [string, undefined] => {
+	const host = URL_REGEX.exec(token);
+	if (host && host.groups && host.groups.host) {
+		if (onlyRelative) {
+			return [
+				undefined,
+				`Only relative URLs are allowed. Skipping absolute URL ${token}.`,
+			];
+		}
+
+		if (disallowPorts && host.groups.host.match(HOST_WITH_PORT_REGEX)) {
+			return [
+				undefined,
+				`Specifying ports is not supported. Skipping absolute URL ${token}.`,
+			];
+		}
+
+		return [
+			`https://${host.groups.host}${extractPathname(
+				host.groups.path,
+				includeSearch,
+				includeHash
+			)}`,
+			undefined,
+		];
+	} else {
+		if (!token.startsWith("/") && onlyRelative) {
+			token = `/${token}`;
+		}
+
+		const path = PATH_REGEX.exec(token);
+		if (path) {
+			try {
+				return [extractPathname(token, includeSearch, includeHash), undefined];
+			} catch {
+				return [undefined, `Error parsing URL segment ${token}. Skipping.`];
+			}
+		}
+	}
+
+	return [
+		undefined,
+		onlyRelative
+			? "URLs should begin with a forward-slash."
+			: 'URLs should either be relative (e.g. begin with a forward-slash), or use HTTPS (e.g. begin with "https://").',
+	];
+};
+
+export function urlHasHost(token: string): boolean {
+	const host = URL_REGEX.exec(token);
+	return Boolean(host && host.groups && host.groups.host);
+}