1 files changed, 96 insertions, 0 deletions
diff --git a/packages/internal-helpers/src/remote.ts b/packages/internal-helpers/src/remote.ts
new file mode 100644
index 000000000..0023deff8
--- /dev/null
+++ b/packages/internal-helpers/src/remote.ts
@@ -0,0 +1,96 @@
+export type RemotePattern = {
+	hostname?: string;
+	pathname?: string;
+	protocol?: string;
+	port?: string;
+};
+
+export function matchPattern(url: URL, remotePattern: RemotePattern) {
+	return (
+		matchProtocol(url, remotePattern.protocol) &&
+		matchHostname(url, remotePattern.hostname, true) &&
+		matchPort(url, remotePattern.port) &&
+		matchPathname(url, remotePattern.pathname, true)
+	);
+}
+
+export function matchPort(url: URL, port?: string) {
+	return !port || port === url.port;
+}
+
+export function matchProtocol(url: URL, protocol?: string) {
+	return !protocol || protocol === url.protocol.slice(0, -1);
+}
+
+export function matchHostname(
+	url: URL,
+	hostname?: string,
+	allowWildcard?: boolean,
+) {
+	if (!hostname) {
+		return true;
+	} else if (!allowWildcard || !hostname.startsWith("*")) {
+		return hostname === url.hostname;
+	} else if (hostname.startsWith("**.")) {
+		const slicedHostname = hostname.slice(2); // ** length
+		return (
+			slicedHostname !== url.hostname && url.hostname.endsWith(slicedHostname)
+		);
+	} else if (hostname.startsWith("*.")) {
+		const slicedHostname = hostname.slice(1); // * length
+		const additionalSubdomains = url.hostname
+			.replace(slicedHostname, "")
+			.split(".")
+			.filter(Boolean);
+		return additionalSubdomains.length === 1;
+	}
+
+	return false;
+}
+
+export function matchPathname(
+	url: URL,
+	pathname?: string,
+	allowWildcard?: boolean,
+) {
+	if (!pathname) {
+		return true;
+	} else if (!allowWildcard || !pathname.endsWith("*")) {
+		return pathname === url.pathname;
+	} else if (pathname.endsWith("/**")) {
+		const slicedPathname = pathname.slice(0, -2); // ** length
+		return (
+			slicedPathname !== url.pathname && url.pathname.startsWith(slicedPathname)
+		);
+	} else if (pathname.endsWith("/*")) {
+		const slicedPathname = pathname.slice(0, -1); // * length
+		const additionalPathChunks = url.pathname
+			.replace(slicedPathname, "")
+			.split("/")
+			.filter(Boolean);
+		return additionalPathChunks.length === 1;
+	}
+
+	return false;
+}
+
+export function isRemoteAllowed(
+	src: string,
+	{
+		domains,
+		remotePatterns,
+	}: {
+		domains: string[];
+		remotePatterns: RemotePattern[];
+	},
+): boolean {
+	if (!URL.canParse(src)) {
+		return false;
+	}
+
+	const url = new URL(src);
+	return (
+		domains.some((domain) => matchHostname(url, domain)) ||
+		remotePatterns.some((remotePattern) => matchPattern(url, remotePattern))
+	);
+}