feat(media): emit external proxy urls with a readable path and extension (#1793)

fluxer_api/pkgs/media_proxy_utils/src/ExternalMediaProxyPathCodec.test.ts

@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {
+	buildExternalMediaProxyPath,
+	buildV2ExternalMediaProxyPath,
+	reconstructOriginalUrl,
+} from '@pkgs/media_proxy_utils/src/ExternalMediaProxyPathCodec';
+import {describe, expect, it} from 'vitest';
+
+const ROUND_TRIP_URLS = [
+	'https://static.klipy.com/ii/c8/28/HkAKKCzZ.webp',
+	'https://static.klipy.com/ii/HkAKKCzZ.webp?v=query_param&goes=here',
+	'https://example.com:8443/a.png',
+	'https://avatars.githubusercontent.com/u/241303489?v=4',
+	'http://example.com/plain.gif',
+	'https://example.com/deep/nested/path/to/file.jpeg',
+	'https://example.com/file.png?a=1&b=2&c=3',
+	'https://example.com/spaced%20name.png',
+	'https://example.com/unicode/%C3%A5%C3%A4%C3%B6.png',
+	'https://example.com/file.png?redirect=https%3A%2F%2Fother.example%2Fx.png',
+	'https://sub.domain.example.co.uk/a/b.webp',
+];
+
+describe('buildExternalMediaProxyPath', () => {
+	it('emits the plain path shape with the extension last', () => {
+		expect(buildExternalMediaProxyPath('https://static.klipy.com/ii/c8/28/HkAKKCzZ.webp')).toBe(
+			'https/static.klipy.com/ii/c8/28/HkAKKCzZ.webp',
+		);
+	});
+
+	it('puts an encoded query, leading question mark included, ahead of the protocol', () => {
+		expect(buildExternalMediaProxyPath('https://static.klipy.com/ii/HkAKKCzZ.webp?v=query_param&goes=here')).toBe(
+			'%3Fv%3Dquery_param%26goes%3Dhere/https/static.klipy.com/ii/HkAKKCzZ.webp',
+		);
+	});
+
+	it('keeps a non default port on the host segment', () => {
+		expect(buildExternalMediaProxyPath('https://example.com:8443/a.png')).toBe('https/example.com:8443/a.png');
+	});
+
+	it('preserves the http scheme', () => {
+		expect(buildExternalMediaProxyPath('http://example.com/a.gif')).toBe('http/example.com/a.gif');
+	});
+
+	it('handles a root url with no path', () => {
+		expect(buildExternalMediaProxyPath('https://example.com/')).toBe('https/example.com');
+	});
+
+	it('never emits the v2 prefix any more', () => {
+		for (const url of ROUND_TRIP_URLS) {
+			expect(buildExternalMediaProxyPath(url).startsWith('v2/')).toBe(false);
+		}
+	});
+
+	it('ends in the source file extension so extension based cdn caching applies', () => {
+		for (const [url, ext] of [
+			['https://example.com/a.webp', '.webp'],
+			['https://example.com/a.png?x=1', '.png'],
+			['https://example.com/a/b/c.jpeg', '.jpeg'],
+		] as const) {
+			expect(buildExternalMediaProxyPath(url).endsWith(ext)).toBe(true);
+		}
+	});
+
+	it('rejects a url it cannot parse', () => {
+		expect(() => buildExternalMediaProxyPath('not a url')).toThrow();
+	});
+});
+
+describe('reconstructOriginalUrl', () => {
+	it('round trips every supported shape', () => {
+		for (const url of ROUND_TRIP_URLS) {
+			expect(reconstructOriginalUrl(buildExternalMediaProxyPath(url))).toBe(url);
+		}
+	});
+
+	it('decodes an externally produced path verbatim', () => {
+		expect(
+			reconstructOriginalUrl('%3Fv%3Dquery_param%26goes%3Dhere/https/static.klipy.com/ii/c8/28/HkAKKCzZ.webp'),
+		).toBe('https://static.klipy.com/ii/c8/28/HkAKKCzZ.webp?v=query_param&goes=here');
+	});
+
+	it('does not double the question mark when the query segment carries one', () => {
+		const decoded = reconstructOriginalUrl('%3Fa%3D1/https/example.com/x.png');
+		expect(decoded).toBe('https://example.com/x.png?a=1');
+		expect(decoded).not.toContain('??');
+	});
+
+	it('still accepts a query segment without a leading question mark', () => {
+		expect(reconstructOriginalUrl('a%3D1/https/example.com/x.png')).toBe('https://example.com/x.png?a=1');
+	});
+
+	it('still decodes v2 paths so links already sent keep working', () => {
+		expect(reconstructOriginalUrl(buildV2ExternalMediaProxyPath('https://example.com/a.png?x=1'))).toBe(
+			'https://example.com/a.png?x=1',
+		);
+	});
+
+	it('rejects a path that has no host after the protocol', () => {
+		expect(() => reconstructOriginalUrl('https')).toThrow();
+	});
+
+	it('rejects an empty v2 payload', () => {
+		expect(() => reconstructOriginalUrl('v2/')).toThrow();
+	});
+});

fluxer_api/pkgs/media_proxy_utils/src/ExternalMediaProxyPathCodec.ts

@@ -74,7 +74,8 @@ function reconstructLegacyOriginalUrl(proxyUrlPath: string): string {
 	const query = encodedQuery ? decodeLegacyComponent(encodedQuery) : '';
 	const path = decodeLegacyComponent(encodedPath);
 	const {hostname, port} = decodeLegacyHostAndPort(hostPart);
-	return `${protocol}://${hostname}${port ? `:${port}` : ''}/${path}${query ? `?${query}` : ''}`;
+	const normalizedQuery = query.startsWith('?') ? query.slice(1) : query;
+	return `${protocol}://${hostname}${port ? `:${port}` : ''}/${path}${normalizedQuery ? `?${normalizedQuery}` : ''}`;
 }
 
 function reconstructV2OriginalUrl(proxyUrlPath: string): string {
@@ -85,11 +86,28 @@ function reconstructV2OriginalUrl(proxyUrlPath: string): string {
 	return decodeV2PathComponent(encodedOriginalUrl);
 }
 
-export function buildExternalMediaProxyPath(inputUrl: string): string {
+export function buildV2ExternalMediaProxyPath(inputUrl: string): string {
 	const parsedUrl = new URL(inputUrl);
 	return `${V2_PATH_PREFIX}${encodeV2PathComponent(parsedUrl.toString())}`;
 }
 
+export function buildExternalMediaProxyPath(inputUrl: string): string {
+	const parsedUrl = new URL(inputUrl);
+	const protocol = parsedUrl.protocol.replace(/:$/u, '');
+	const host = parsedUrl.port ? `${parsedUrl.hostname}:${parsedUrl.port}` : parsedUrl.hostname;
+	const path = parsedUrl.pathname
+		.replace(/^\//u, '')
+		.split('/')
+		.map((segment) => encodeURIComponent(segment))
+		.join('/');
+	const segments = parsedUrl.search ? [encodeURIComponent(parsedUrl.search)] : [];
+	segments.push(protocol, host);
+	if (path) {
+		segments.push(path);
+	}
+	return segments.join('/');
+}
+
 export function reconstructOriginalUrl(proxyUrlPath: string): string {
 	const reconstructedUrl = proxyUrlPath.startsWith(V2_PATH_PREFIX)
 		? reconstructV2OriginalUrl(proxyUrlPath)