fix: change CloudStorageFileSystemProvider to throw a FileAlreadyExistsException if copy receives a 412 (#815)

Author: BenWhitehead

google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/CloudStorageFileSystemProvider.java

@@ -468,7 +468,7 @@ private SeekableByteChannel newWriteChannel(Path path, Set<? extends OpenOption>
  infoBuilder.build(),
  writeOptions.toArray(new Storage.BlobWriteOption[writeOptions.size()])));
  } catch (StorageException oops) {
- throw asIoException(oops);
+ throw asIoException(oops, false);
  }
  }
 
@@ -688,7 +688,7 @@ public void copy(Path source, Path target, CopyOption... options) throws IOExcep
  retryHandler.handleStorageException(oops);
  // we're being aggressive by retrying even on scenarios where we'd normally reopen.
  } catch (StorageException retriesExhaustedException) {
- throw asIoException(retriesExhaustedException);
+ throw asIoException(retriesExhaustedException, true);
  }
  }
  }
@@ -1013,12 +1013,18 @@ Page<Bucket> listBuckets(Storage.BucketListOption... options) {
  return storage.list(options);
  }
 
- private IOException asIoException(StorageException oops) {
+ private IOException asIoException(StorageException oops, boolean operationWasCopy) {
  // RPC API can only throw StorageException, but CloudStorageFileSystemProvider
  // can only throw IOException. Square peg, round hole.
  // TODO(#810): Research if other codes should be translated similarly.
  if (oops.getCode() == 404) {
  return new NoSuchFileException(oops.getReason());
+ } else if (operationWasCopy && oops.getCode() == 412) {
+ return new FileAlreadyExistsException(
+ String.format(
+ "Copy failed for reason '%s'. This most likely means the destination already exists"
+ + " and java.nio.file.StandardCopyOption.REPLACE_EXISTING was not specified.",
+ oops.getReason()));
  }
 
  Throwable cause = oops.getCause();

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/it/ITGcsNio.java

@@ -53,6 +53,7 @@
 import java.nio.channels.FileChannel;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.SeekableByteChannel;
+import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.FileSystem;
 import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
@@ -1108,6 +1109,63 @@ public void testListObject() throws IOException {
  assertThat(objects.size()).isEqualTo(1);
  }
 
+ @Test(expected = FileAlreadyExistsException.class)
+ public void testCopy_replaceFile_withoutOption() throws IOException {
+ CloudStorageFileSystem fs = getTestBucket();
+ String uuid = UUID.randomUUID().toString();
+
+ CloudStoragePath foo = fs.getPath(uuid, "foo.txt");
+ CloudStoragePath bar = fs.getPath(uuid, "bar.txt");
+
+ try {
+ Files.createFile(foo);
+ Files.createFile(bar);
+
+ Files.copy(foo, bar);
+ } finally {
+ Files.deleteIfExists(foo);
+ Files.deleteIfExists(bar);
+ }
+ }
+
+ @Test
+ public void testCopy_replaceFile_withOption() throws IOException {
+ CloudStorageFileSystem fs = getTestBucket();
+ String uuid = UUID.randomUUID().toString();
+
+ CloudStoragePath foo = fs.getPath(uuid, "foo.txt");
+ CloudStoragePath bar = fs.getPath(uuid, "bar.txt");
+
+ try {
+ Files.createFile(foo);
+ Files.createFile(bar);
+
+ Files.copy(foo, bar, StandardCopyOption.REPLACE_EXISTING);
+ } finally {
+ Files.deleteIfExists(foo);
+ Files.deleteIfExists(bar);
+ }
+ }
+
+ @Test(expected = NoSuchFileException.class)
+ public void testCopy_replaceFile_withOption_srcDoesNotExist() throws IOException {
+ CloudStorageFileSystem fs = getTestBucket();
+ String uuid = UUID.randomUUID().toString();
+
+ CloudStoragePath foo = fs.getPath(uuid, "foo.txt");
+ CloudStoragePath bar = fs.getPath(uuid, "bar.txt");
+
+ try {
+ // explicitly do not create foo
+ Files.createFile(bar);
+
+ Files.copy(foo, bar);
+ } finally {
+ Files.deleteIfExists(foo);
+ Files.deleteIfExists(bar);
+ }
+ }
+
  private CloudStorageFileSystem getTestBucket() throws IOException {
  // in typical usage we use the single-argument version of forBucket
  // and rely on the user being logged into their project with the