added integration test

Author: v-pratap

google/cloud/storage/tests/object_checksum_integration_test.cc

@@ -145,14 +145,8 @@ TEST_F(ObjectChecksumIntegrationTest, WriteObjectDefault) {
   EXPECT_THAT(os.computed_hash(),
               HasSubstr(ComputeCrc32cChecksum(LoremIpsum())));
   if (meta->has_metadata("x_emulator_upload")) {
-    if (UsingGrpc()) {
-      EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_crc32c", _)));
-      EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_no_md5", _)));
-    } else {
-      // Streaming uploads over REST cannot include checksums
-      EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_no_crc32c", _)));
-      EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_no_md5", _)));
-    }
+    EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_crc32c", _)));
+    EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_no_md5", _)));
   }
 }
 
@@ -200,14 +194,8 @@ TEST_F(ObjectChecksumIntegrationTest, WriteObjectExplicitEnable) {
   EXPECT_THAT(os.computed_hash(),
               HasSubstr(ComputeCrc32cChecksum(LoremIpsum())));
   if (meta->has_metadata("x_emulator_upload")) {
-    if (UsingGrpc()) {
       EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_crc32c", _)));
       EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_no_md5", _)));
-    } else {
-      // Streaming uploads over REST cannot include checksums
-      EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_no_crc32c", _)));
-      EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_no_md5", _)));
-    }
   }
 }
 
@@ -289,6 +277,54 @@ TEST_F(ObjectChecksumIntegrationTest, WriteObjectUploadBadChecksum) {
   ASSERT_THAT(stream.metadata(), Not(IsOk()));
 }
 
+/// @test Verify that full object checksums are sent in the final chunk.
+TEST_F(ObjectChecksumIntegrationTest, WriteObjectWithFullChecksumValidation) {
+  auto client = MakeIntegrationTestClient();
+  auto object_name = MakeRandomObjectName();
+  auto content = LoremIpsum();
+  auto expected_crc32c = ComputeCrc32cChecksum(content);
+
+  auto os = client.WriteObject(bucket_name_, object_name,
+                               DisableCrc32cChecksum(false),
+                               DisableMD5Hash(true), 
+                               IfGenerationMatch(0));
+  os << content;
+  os.Close();
+  auto meta = os.metadata();
+  ASSERT_STATUS_OK(meta);
+  ScheduleForDelete(*meta);
+
+  EXPECT_EQ(os.computed_hash(), expected_crc32c);
+  
+  if (meta->has_metadata("x_emulator_upload")) {
+    EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_crc32c", expected_crc32c)));
+    EXPECT_THAT(meta->metadata(), Contains(Pair("x_emulator_no_md5", "true")));
+  }
+}
+
+/// @test Verify that the upload fails when the provided CRC32C checksum does not match the data.
+TEST_F(ObjectChecksumIntegrationTest, WriteObjectWithIncorrectChecksumValue) {
+  auto client = MakeIntegrationTestClient();
+  auto object_name = MakeRandomObjectName();
+  auto content = LoremIpsum();
+
+  auto bad_crc32c = ComputeCrc32cChecksum("this is not the data being uploaded");
+
+  auto os = client.WriteObject(bucket_name_, object_name,
+                               Crc32cChecksumValue(bad_crc32c),
+                               DisableMD5Hash(true),
+                               IfGenerationMatch(0));
+  
+  os << content;
+  os.Close();
+  EXPECT_TRUE(os.bad());
+  auto meta = os.metadata();
+  EXPECT_THAT(meta, Not(IsOk()));
+  
+  // The server returns FAILED_PRECONDITION (412) for checksum mismatches during finalization
+  EXPECT_THAT(meta, StatusIs(StatusCode::kFailedPrecondition));
+}
+
 /// @test Verify that CRC32C checksums are computed by default on downloads.
 TEST_F(ObjectChecksumIntegrationTest, ReadObjectDefault) {
   // TODO(#14385) - the emulator does not support this feature for gRPC.
@@ -385,3 +421,4 @@ GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END
 }  // namespace storage
 }  // namespace cloud
 }  // namespace google
+