feat(rust-core): add zstd chunk compression support and rewrite partially referenced packs during prune

test/test.ts

@@ -6,10 +6,11 @@ import { ContainerArchive } from '../ts/index.js';
 
 const testRepoPath = path.resolve('.nogit/test-repo');
 const testRepoEncryptedPath = path.resolve('.nogit/test-repo-encrypted');
+const testRepoZstdPath = path.resolve('.nogit/test-repo-zstd');
 
 // Clean up test directories before tests
 tap.preTask('cleanup test directories', async () => {
-  for (const p of [testRepoPath, testRepoEncryptedPath]) {
+  for (const p of [testRepoPath, testRepoEncryptedPath, testRepoZstdPath]) {
     if (fs.existsSync(p)) {
       fs.rmSync(p, { recursive: true });
     }
@@ -250,4 +251,50 @@ tap.test('should open encrypted repository with correct passphrase', async () =>
   await encRepo.close();
 });
 
+// ==================== Zstd Compression ====================
+
+tap.test('should work with zstd compression', async () => {
+  // Init repo — the config.json will have compression: "gzip" by default.
+  // To test zstd, we manually update the config after init.
+  const zstdRepo = await ContainerArchive.init(testRepoZstdPath);
+  await zstdRepo.close();
+
+  // Patch config.json to use zstd
+  const configPath = path.join(testRepoZstdPath, 'config.json');
+  const config = JSON.parse(fs.readFileSync(configPath, 'utf-8'));
+  config.compression = 'zstd';
+  fs.writeFileSync(configPath, JSON.stringify(config, null, 2));
+
+  // Reopen with zstd config
+  const repo2 = await ContainerArchive.open(testRepoZstdPath);
+
+  // Ingest
+  const testData = Buffer.alloc(256 * 1024, 'zstd-compressed-data');
+  const snapshot = await repo2.ingest(stream.Readable.from(testData), {
+    tags: { compression: 'zstd' },
+    items: [{ name: 'zstd-data.bin' }],
+  });
+
+  expect(snapshot.newChunks).toBeGreaterThan(0);
+
+  // Restore and verify
+  const restoreStream = await repo2.restore(snapshot.id);
+  const chunks: Buffer[] = [];
+  await new Promise<void>((resolve, reject) => {
+    restoreStream.on('data', (chunk: Buffer) => chunks.push(chunk));
+    restoreStream.on('end', resolve);
+    restoreStream.on('error', reject);
+  });
+
+  const restored = Buffer.concat(chunks);
+  expect(restored.length).toEqual(testData.length);
+  expect(restored.equals(testData)).toBeTrue();
+
+  // Verify
+  const verifyResult = await repo2.verify({ level: 'full' });
+  expect(verifyResult.ok).toBeTrue();
+
+  await repo2.close();
+});
+
 export default tap.start();