Fix range-filtered remote ZIP decoding

packages/php-wasm/stream-compression/src/test/decode-remote-zip.spec.ts

@@ -0,0 +1,71 @@
+import { collectBytes } from '../utils/collect-bytes';
+import { decodeRemoteZip } from '../zip/decode-remote-zip';
+import { encodeZip } from '../zip/encode-zip';
+
+describe('decodeRemoteZip', () => {
+	it('emits selected files from range responses', async () => {
+		const targetPath = 'selected.txt';
+		const zipBytes = await createLargeZip(targetPath);
+		const originalFetch = globalThis.fetch;
+		globalThis.fetch = createRangeFetch(zipBytes);
+
+		try {
+			const decoder = new TextDecoder();
+			const stream = await decodeRemoteZip(
+				'https://example.com/archive.zip',
+				(entry) => decoder.decode(entry.path) === targetPath
+			);
+			const files = [];
+			for await (const file of stream) {
+				files.push(file);
+			}
+
+			expect(files).toHaveLength(1);
+			expect(decoder.decode(files[0].path)).toBe(targetPath);
+			expect(decoder.decode(files[0].bytes)).toBe('selected contents');
+		} finally {
+			globalThis.fetch = originalFetch;
+		}
+	});
+});
+
+async function createLargeZip(targetPath: string): Promise<Uint8Array> {
+	let state = 0x12345678;
+	const noise = new Uint8Array(1_200_000);
+	for (let i = 0; i < noise.length; i++) {
+		state ^= state << 13;
+		state ^= state >>> 17;
+		state ^= state << 5;
+		noise[i] = state;
+	}
+
+	return await collectBytes(
+		encodeZip([
+			new File(['selected contents'], targetPath),
+			new File([noise], 'noise.bin'),
+		])
+	);
+}
+
+function createRangeFetch(zipBytes: Uint8Array): typeof fetch {
+	return async (_input, init) => {
+		if (init?.method === 'HEAD') {
+			return new Response(null, {
+				headers: { 'Content-Length': String(zipBytes.byteLength) },
+			});
+		}
+
+		const range = new Headers(init?.headers).get('Range');
+		if (!range) {
+			return new Response(zipBytes);
+		}
+
+		const match = /^bytes=(\d+)-(\d+)$/.exec(range);
+		if (!match) {
+			throw new Error(`Unexpected Range header: ${range}`);
+		}
+		const from = Number(match[1]);
+		const to = Number(match[2]);
+		return new Response(zipBytes.slice(from, to + 1), { status: 206 });
+	};
+}

packages/php-wasm/stream-compression/src/zip/decode-remote-zip.ts

@@ -307,8 +307,8 @@ function fetchPartitionedEntries(
 				// There may be some extra files between the ones we're
 				// interested in. Let's filter out any files that got
 				// intertwined in the byte stream.
-				const isOneOfRequestedPaths = requestedPaths.find(
-					(entry) => entry.path === file.path
+				const isOneOfRequestedPaths = requestedPaths.find((entry) =>
+					uint8ArraysEqual(entry.path, file.path)
 				);
 				if (!isOneOfRequestedPaths) {
 					continue;
@@ -327,6 +327,13 @@ function fetchPartitionedEntries(
 	};
 }
 
+function uint8ArraysEqual(left: Uint8Array, right: Uint8Array): boolean {
+	return (
+		left.length === right.length &&
+		left.every((value, index) => value === right[index])
+	);
+}
+
 /**
  * Requests a chunk of bytes from the bytes source.
  *