fix: use projectId from CloudStorageConfig

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

@@ -103,15 +103,24 @@ boolean seemsLikeADirectoryAndUsePseudoDirectories(Storage storage) {
     if (!prefix.endsWith("/")) {
       prefix += "/";
     }
-    Page<Blob> list =
-        storage.list(
-            this.bucket(),
-            Storage.BlobListOption.prefix(prefix),
-            // we only look at the first result, so no need for a bigger page.
-            Storage.BlobListOption.pageSize(1),
-            fileSystem.provider().getProject() == null
-                ? null
-                : Storage.BlobListOption.userProject(fileSystem.provider().getProject()));
+    String userProject = fileSystem.config().userProject();
+    Page<Blob> list = null;
+    if (userProject != null) {
+      list =
+          storage.list(
+              this.bucket(),
+              Storage.BlobListOption.prefix(prefix),
+              // we only look at the first result, so no need for a bigger page.
+              Storage.BlobListOption.pageSize(1),
+              Storage.BlobListOption.userProject(userProject));
+    } else {
+      list =
+          storage.list(
+              this.bucket(),
+              Storage.BlobListOption.prefix(prefix),
+              // we only look at the first result, so no need for a bigger page.
+              Storage.BlobListOption.pageSize(1));
+    }
     for (Blob b : list.getValues()) {
       // if this blob starts with our prefix and then a slash, then prefix is indeed a folder!
       if (b.getBlobId() == null) {

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

@@ -0,0 +1,98 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.storage.contrib.nio;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import com.google.api.gax.paging.Page;
+import com.google.cloud.storage.Blob;
+import com.google.cloud.storage.BlobId;
+import com.google.cloud.storage.Storage;
+import com.google.cloud.storage.StorageOptions;
+import com.google.cloud.testing.junit4.MultipleAttemptsRule;
+import com.google.common.collect.Lists;
+import java.nio.file.Files;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@code Files.isDirectory()}. */
+@RunWith(JUnit4.class)
+public class CloudStorageIsDirectoryTest {
+  @Rule public final MultipleAttemptsRule multipleAttemptsRule = new MultipleAttemptsRule(3);
+
+  private StorageOptions mockOptions;
+  private Storage mockStorage;
+
+  @Before
+  public void before() {
+    mockOptions = mock(StorageOptions.class);
+    mockStorage = mock(Storage.class);
+    when(mockOptions.getService()).thenReturn(mockStorage);
+    CloudStorageFileSystemProvider.setStorageOptions(mockOptions);
+  }
+
+  @Test
+  public void testIsDirectoryNoUserProject() {
+    CloudStorageFileSystem fs =
+        CloudStorageFileSystem.forBucket("bucket", CloudStorageConfiguration.DEFAULT);
+    when(mockStorage.get(BlobId.of("bucket", "test", null)))
+        .thenThrow(new IllegalArgumentException());
+    Page<Blob> pages = mock(Page.class);
+    Blob blob = mock(Blob.class);
+    when(blob.getBlobId()).thenReturn(BlobId.of("bucket", "test/hello.txt"));
+    when(pages.getValues()).thenReturn(Lists.newArrayList(blob));
+    when(mockStorage.list(
+            "bucket", Storage.BlobListOption.prefix("test/"), Storage.BlobListOption.pageSize(1)))
+        .thenReturn(pages);
+
+    Files.isDirectory(fs.getPath("test"));
+    verify(mockStorage, times(1))
+        .list("bucket", Storage.BlobListOption.prefix("test/"), Storage.BlobListOption.pageSize(1));
+  }
+
+  @Test
+  public void testIsDirectoryWithUserProject() {
+    CloudStorageFileSystem fs =
+        CloudStorageFileSystem.forBucket(
+            "bucket", CloudStorageConfiguration.builder().userProject("project-id").build());
+    when(mockStorage.get(BlobId.of("bucket", "test", null)))
+        .thenThrow(new IllegalArgumentException());
+    Page<Blob> pages = mock(Page.class);
+    Blob blob = mock(Blob.class);
+    when(blob.getBlobId()).thenReturn(BlobId.of("bucket", "test/hello.txt"));
+    when(pages.getValues()).thenReturn(Lists.newArrayList(blob));
+    when(mockStorage.list(
+            "bucket",
+            Storage.BlobListOption.prefix("test/"),
+            Storage.BlobListOption.pageSize(1),
+            Storage.BlobListOption.userProject("project-id")))
+        .thenReturn(pages);
+    Files.isDirectory(fs.getPath("test"));
+    verify(mockStorage, times(1))
+        .list(
+            "bucket",
+            Storage.BlobListOption.prefix("test/"),
+            Storage.BlobListOption.pageSize(1),
+            Storage.BlobListOption.userProject("project-id"));
+  }
+}