fix: update UploadCallable to use createFrom to avoid NPE trying to resolve resulting object

google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/ParallelUploadConfig.java

@@ -47,7 +47,7 @@ private ParallelUploadConfig(
     this.prefix = prefix;
     this.bucketName = bucketName;
     this.targetOptsPerRequest = targetOptsPerRequest;
-    this.writeOptsPerRequest = writeOptsPerRequest;
+    this.writeOptsPerRequest = applySkipIfExists(skipIfExists, writeOptsPerRequest);
   }
 
   /** If a corresponding object already exists skip uploading the object */
@@ -115,6 +115,17 @@ public static Builder newBuilder() {
     return new Builder();
   }
 
+  private static List<BlobWriteOption> applySkipIfExists(
+      boolean skipIfExists, List<BlobWriteOption> writeOptsPerRequest) {
+    if (skipIfExists) {
+      return writeOptsPerRequest.isEmpty()
+          ? ImmutableList.of(BlobWriteOption.generationMatch(0))
+          : ImmutableList.copyOf(
+              BlobWriteOption.dedupe(writeOptsPerRequest, BlobWriteOption.generationMatch(0L)));
+    }
+    return writeOptsPerRequest;
+  }
+
   @BetaApi
   public static final class Builder {
 

google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/UploadCallable.java

@@ -64,12 +64,14 @@ private UploadResult uploadWithoutChunking() {
     long bytesCopied = -1L;
     try {
       Optional<BlobInfo> newBlob;
-      try (FileChannel r = FileChannel.open(sourceFile, StandardOpenOption.READ);
-          WriteChannel w = storage.writer(originalBlob, opts)) {
+      WriteChannel w = storage.writer(originalBlob, opts);
+      try (FileChannel r = FileChannel.open(sourceFile, StandardOpenOption.READ)) {
         w.setChunkSize(transferManagerConfig.getPerWorkerBufferSize());
         bytesCopied = ByteStreams.copy(r, w);
-        newBlob = PackagePrivateMethodWorkarounds.maybeGetBlobInfoFunction().apply(w);
+      } finally {
+        w.close();
       }
+      newBlob = PackagePrivateMethodWorkarounds.maybeGetBlobInfoFunction().apply(w);
       return UploadResult.newBuilder(originalBlob, TransferStatus.SUCCESS)
           .setUploadedBlob(newBlob.get())
           .build();

google-cloud-storage/src/test/java/com/google/cloud/storage/it/ITTransferManagerTest.java

@@ -131,6 +131,11 @@ public void uploadFiles() throws Exception {
       UploadJob job = transferManager.uploadFiles(files, parallelUploadConfig);
       List<UploadResult> uploadResults = job.getUploadResults();
       assertThat(uploadResults).hasSize(3);
+      assertThat(
+              uploadResults.stream()
+                  .filter(result -> result.getStatus() == TransferStatus.SUCCESS)
+                  .collect(Collectors.toList()))
+          .hasSize(3);
     }
   }
 
@@ -153,6 +158,11 @@ public void uploadFilesWithOpts() throws Exception {
       UploadJob job = transferManager.uploadFiles(files, parallelUploadConfig);
       List<UploadResult> uploadResults = job.getUploadResults();
       assertThat(uploadResults).hasSize(3);
+      assertThat(
+              uploadResults.stream()
+                  .filter(result -> result.getStatus() == TransferStatus.SUCCESS)
+                  .collect(Collectors.toList()))
+          .hasSize(3);
     }
   }
 
@@ -181,6 +191,11 @@ public void uploadFilesOneFailure() throws Exception {
                   .filter(x -> x.getStatus() == TransferStatus.FAILED_TO_START)
                   .collect(Collectors.toList()))
           .hasSize(1);
+      assertThat(
+              uploadResults.stream()
+                  .filter(result -> result.getStatus() == TransferStatus.SUCCESS)
+                  .collect(Collectors.toList()))
+          .hasSize(3);
     }
   }
 
@@ -217,6 +232,28 @@ public void uploadNonexistentFile() throws Exception {
     }
   }
 
+  @Test
+  public void uploadFailsSkipIfExists() throws Exception {
+    TransferManagerConfig config =
+        TransferManagerConfigTestingInstances.defaults(storage.getOptions()).toBuilder().build();
+    String bucketName = bucket.getName();
+    try (TransferManager transferManager = config.getService();
+        TmpFile tmpFile = DataGenerator.base64Characters().tempFile(baseDir, objectContentSize)) {
+      ParallelUploadConfig parallelUploadConfig =
+          ParallelUploadConfig.newBuilder().setBucketName(bucketName).setSkipIfExists(true).build();
+      UploadJob jobInitUpload =
+          transferManager.uploadFiles(ImmutableList.of(tmpFile.getPath()), parallelUploadConfig);
+      List<UploadResult> uploadResults = jobInitUpload.getUploadResults();
+      assertThat(uploadResults.get(0).getStatus()).isEqualTo(TransferStatus.SUCCESS);
+      UploadJob failedSecondUpload =
+          transferManager.uploadFiles(ImmutableList.of(tmpFile.getPath()), parallelUploadConfig);
+      List<UploadResult> failedResult = failedSecondUpload.getUploadResults();
+      assertThat(failedResult.get(0).getStatus()).isEqualTo(TransferStatus.FAILED_TO_FINISH);
+      assertThat(failedResult.get(0).getException()).isInstanceOf(StorageException.class);
+      assertThat(failedResult.get(0).getException().getMessage()).contains("Precondition Failed");
+    }
+  }
+
   @Test
   public void downloadBlobs() throws Exception {
     TransferManagerConfig config =