Fix #7980: Enhanced image writer error messages with actionable installation guidance

test_env.py

@@ -0,0 +1,16 @@
+"""
+Manual environment check for versions of PyTorch and MONAI.
+
+This script helps verify the runtime versions of key libraries during manual testing
+of writer error messages or environment troubleshooting.
+
+Note:
+- This is intended for manual execution only.
+- Consider moving to a diagnostics folder or integrating into automated tests.
+"""
+
+import torch
+import monai
+
+print("Torch version:", torch.__version__)
+print("MONAI version:", monai.__version__)

test_writer_error.py

@@ -0,0 +1,21 @@
+from monai.data.image_writer import resolve_writer, OptionalImportError, SUPPORTED_WRITERS, EXT_WILDCARD, ITKWriter
+
+# Fake extension to simulate unsupported file type
+ext = "fakeext"
+
+print(f"Before clearing fallback writers: {SUPPORTED_WRITERS.get(EXT_WILDCARD)}")
+
+# Temporarily clear fallback writers to simulate no support scenario
+SUPPORTED_WRITERS[EXT_WILDCARD] = ()
+
+try:
+    # Try resolving writer for fake unsupported extension with error flag
+    writers = resolve_writer(ext, error_if_not_found=True)
+except OptionalImportError as e:
+    # Catch and print the enhanced OptionalImportError with package hints
+    print("Caught OptionalImportError:", e)
+finally:
+    # Restore the fallback writers to avoid side effects on other tests
+    SUPPORTED_WRITERS[EXT_WILDCARD] = (ITKWriter,)
+
+print(f"After restoring fallback writers: {SUPPORTED_WRITERS.get(EXT_WILDCARD)}")