From da1ec6e4855e54fe10d674c1152cb6b56f6cac80 Mon Sep 17 00:00:00 2001
From: Thiyagu K <thiyaguk@google.com>
Date: Wed, 13 Aug 2025 07:34:22 +0000
Subject: [PATCH 1/2] fix-Set crc32c as the default option

---
 src/transfer-manager.ts | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/transfer-manager.ts b/src/transfer-manager.ts
index dd4e41eeb..a0b5d5b08 100644
--- a/src/transfer-manager.ts
+++ b/src/transfer-manager.ts
@@ -127,7 +127,7 @@ export interface UploadFileInChunksOptions {
   uploadId?: string;
   autoAbortFailure?: boolean;
   partsMap?: Map<number, string>;
-  validation?: 'md5' | false;
+  validation?: 'md5' | 'crc32c' | false;
   headers?: {[key: string]: string};
 }
 
@@ -140,7 +140,7 @@ export interface MultiPartUploadHelper {
   uploadPart(
     partNumber: number,
     chunk: Buffer,
-    validation?: 'md5' | false
+    validation?: 'md5' | 'crc32c' | false
   ): Promise<void>;
   completeUpload(): Promise<GaxiosResponse | undefined>;
   abortUpload(): Promise<void>;
@@ -289,7 +289,7 @@ class XMLMultiPartUploadHelper implements MultiPartUploadHelper {
   async uploadPart(
     partNumber: number,
     chunk: Buffer,
-    validation?: 'md5' | false
+    validation?: 'md5' | 'crc32c' | false
   ): Promise<void> {
     const url = `${this.baseUrl}?partNumber=${partNumber}&uploadId=${this.uploadId}`;
     let headers: Headers = this.#setGoogApiClientHeaders();
@@ -299,6 +299,10 @@ class XMLMultiPartUploadHelper implements MultiPartUploadHelper {
       headers = {
         'Content-MD5': hash,
       };
+    } else if (validation === 'crc32c') {
+      const crc = new CRC32C();
+      crc.update(chunk);
+      headers['x-goog-hash'] = `crc32c=${crc.toString()}`;
     }
 
     return AsyncRetry(async bail => {
@@ -806,6 +810,8 @@ export class TransferManager {
     );
     let partNumber = 1;
     let promises: Promise<void>[] = [];
+    const validation =
+      options.validation === undefined ? 'crc32c' : options.validation;
     try {
       if (options.uploadId === undefined) {
         await mpuHelper.initiateUpload(options.headers);
@@ -823,9 +829,7 @@ export class TransferManager {
           promises = [];
         }
         promises.push(
-          limit(() =>
-            mpuHelper.uploadPart(partNumber++, curChunk, options.validation)
-          )
+          limit(() => mpuHelper.uploadPart(partNumber++, curChunk, validation))
         );
       }
       await Promise.all(promises);

From 7bb00e5f7de10b57bf88a68ca339daa8d9103d98 Mon Sep 17 00:00:00 2001
From: Thiyagu K <thiyaguk@google.com>
Date: Mon, 18 Aug 2025 10:04:52 +0000
Subject: [PATCH 2/2] added test cases

---
 test/transfer-manager.ts | 57 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/test/transfer-manager.ts b/test/transfer-manager.ts
index 2582782fa..de0284ceb 100644
--- a/test/transfer-manager.ts
+++ b/test/transfer-manager.ts
@@ -730,5 +730,62 @@ describe('Transfer Manager', () => {
 
       assert(called);
     });
+
+    it('should use CRC32C validation when specified', async () => {
+      mockGeneratorFunction = (bucket, fileName, uploadId, partsMap) => {
+        fakeHelper = sandbox.createStubInstance(FakeXMLHelper);
+        fakeHelper.uploadId = uploadId || '';
+        fakeHelper.partsMap = partsMap || new Map<number, string>();
+        fakeHelper.initiateUpload.resolves();
+        fakeHelper.uploadPart.callsFake((partNumber, chunk, validation) => {
+          assert.strictEqual(validation, 'crc32c');
+
+          return Promise.resolve();
+        });
+        fakeHelper.completeUpload.resolves();
+        fakeHelper.abortUpload.resolves();
+        return fakeHelper;
+      };
+
+      await transferManager.uploadFileInChunks(
+        filePath,
+        {validation: 'crc32c'},
+        mockGeneratorFunction
+      );
+
+      assert.strictEqual(fakeHelper.uploadPart.calledOnce, true);
+    });
+
+    it('should apply crc32c validation by default', async () => {
+      let assertionMade = false;
+
+      mockGeneratorFunction = (bucket, fileName, uploadId, partsMap) => {
+        fakeHelper = sandbox.createStubInstance(FakeXMLHelper);
+        fakeHelper.uploadId = uploadId || '';
+        fakeHelper.partsMap = partsMap || new Map<number, string>();
+        fakeHelper.initiateUpload.resolves();
+
+        fakeHelper.uploadPart.callsFake((partNumber, chunk, validation) => {
+          // Confirm the validation is set to 'crc32c' by default.
+          assert.strictEqual(validation, 'crc32c');
+          assertionMade = true;
+          return Promise.resolve();
+        });
+
+        fakeHelper.completeUpload.resolves();
+        fakeHelper.abortUpload.resolves();
+        return fakeHelper;
+      };
+
+      // Call the function without specifying any validation option.
+      await transferManager.uploadFileInChunks(
+        filePath,
+        {},
+        mockGeneratorFunction
+      );
+
+      assert.strictEqual(fakeHelper.uploadPart.calledOnce, true);
+      assert.strictEqual(assertionMade, true);
+    });
   });
 });