add edge case tests

Author: roseyang62

blob/blob-gcp/src/test/java/com/salesforce/multicloudj/blob/gcp/GcpTransformerTest.java

@@ -21,6 +21,7 @@
 import com.salesforce.multicloudj.blob.driver.ObjectLockConfiguration;
 import com.salesforce.multicloudj.blob.driver.RetentionMode;
 import com.salesforce.multicloudj.common.exceptions.InvalidArgumentException;
+import com.salesforce.multicloudj.common.exceptions.SubstrateSdkException;
 import com.salesforce.multicloudj.common.retries.RetryConfig;
 import org.apache.commons.lang3.tuple.Pair;
 import org.junit.jupiter.api.BeforeEach;
@@ -1047,6 +1048,100 @@ public void testToFilePaths_FollowSymbolicLinks() throws IOException {
         }
     }
 
+    @Test
+    public void testToFilePaths_CircularSymbolicLinks() throws IOException {
+        Path tempDir = Files.createTempDirectory("test-circular-symlink");
+        try {
+            Files.write(tempDir.resolve("file.txt"), "content".getBytes());
+            Path dirA = Files.createDirectory(tempDir.resolve("dirA"));
+            Path dirB = Files.createDirectory(tempDir.resolve("dirB"));
+            Files.createSymbolicLink(dirA.resolve("link-to-b"), dirB);
+            Files.createSymbolicLink(dirB.resolve("link-to-a"), dirA);
+
+            DirectoryUploadRequest request = DirectoryUploadRequest.builder()
+                    .localSourceDirectory(tempDir.toString())
+                    .prefix("uploads/")
+                    .includeSubFolders(true)
+                    .followSymbolicLinks(true)
+                    .build();
+
+            assertThrows(RuntimeException.class, () -> transformer.toFilePaths(request));
+        } finally {
+            // Manual cleanup since Files.walk with FOLLOW_LINKS would fail on circular links
+            Files.deleteIfExists(tempDir.resolve("dirA/link-to-b"));
+            Files.deleteIfExists(tempDir.resolve("dirB/link-to-a"));
+            Files.walk(tempDir)
+                    .sorted(Comparator.reverseOrder())
+                    .map(Path::toFile)
+                    .forEach(File::delete);
+        }
+    }
+
+    @Test
+    public void testToFilePaths_BrokenSymbolicLinks() throws IOException {
+        Path tempDir = Files.createTempDirectory("test-broken-symlink");
+        try {
+            Path file1 = tempDir.resolve("file1.txt");
+            Files.write(file1, "content".getBytes());
+            Files.createSymbolicLink(tempDir.resolve("broken-link"), Paths.get("/non/existent/path"));
+
+            DirectoryUploadRequest request = DirectoryUploadRequest.builder()
+                    .localSourceDirectory(tempDir.toString())
+                    .prefix("uploads/")
+                    .includeSubFolders(true)
+                    .followSymbolicLinks(true)
+                    .build();
+
+            List<Path> paths = transformer.toFilePaths(request);
+            assertEquals(1, paths.size());
+            assertTrue(paths.contains(file1));
+        } finally {
+            Files.walk(tempDir)
+                    .sorted(Comparator.reverseOrder())
+                    .map(Path::toFile)
+                    .forEach(File::delete);
+        }
+    }
+
+    @Test
+    public void testToFilePaths_NestedSymbolicLinks() throws IOException {
+        Path tempDir = Files.createTempDirectory("test-nested-symlink");
+        Path externalDir1 = Files.createTempDirectory("test-nested-target1");
+        Path externalDir2 = Files.createTempDirectory("test-nested-target2");
+        try {
+            Files.write(tempDir.resolve("root.txt"), "root".getBytes());
+            Files.write(externalDir2.resolve("deep.txt"), "deep".getBytes());
+            // externalDir1 contains a symlink to externalDir2
+            Files.createSymbolicLink(externalDir1.resolve("link-to-dir2"), externalDir2);
+            // tempDir contains a symlink to externalDir1
+            Files.createSymbolicLink(tempDir.resolve("link-to-dir1"), externalDir1);
+
+            DirectoryUploadRequest request = DirectoryUploadRequest.builder()
+                    .localSourceDirectory(tempDir.toString())
+                    .prefix("uploads/")
+                    .includeSubFolders(true)
+                    .followSymbolicLinks(true)
+                    .build();
+
+            List<Path> paths = transformer.toFilePaths(request);
+            assertEquals(2, paths.size());
+            assertTrue(paths.contains(tempDir.resolve("root.txt")));
+        } finally {
+            Files.walk(externalDir2)
+                    .sorted(Comparator.reverseOrder())
+                    .map(Path::toFile)
+                    .forEach(File::delete);
+            Files.walk(externalDir1)
+                    .sorted(Comparator.reverseOrder())
+                    .map(Path::toFile)
+                    .forEach(File::delete);
+            Files.walk(tempDir)
+                    .sorted(Comparator.reverseOrder())
+                    .map(Path::toFile)
+                    .forEach(File::delete);
+        }
+    }
+
     @Test
     public void testToBlobKey() {
         Path sourceDir = Paths.get("/source");