Update smoke test (#3346)

Summary:
* Delay the import of torchaudio until the CLI options are parsed.
* Add option to set log level to DEBUG so that it's easy to see the issue with external libraries.

Pull Request resolved: https://github.com/pytorch/audio/pull/3346

Reviewed By: nateanl

Differential Revision: D46022546

Pulled By: mthrok

fbshipit-source-id: 9f988bbd770c2fd2bb260c3cfe02b238a9da2808

test/smoke_test/smoke_test.py

 """Run smoke tests"""
-
 import argparse
+import logging
+
 
-import torchaudio  # noqa: F401
-import torchaudio.compliance.kaldi  # noqa: F401
-import torchaudio.datasets  # noqa: F401
-import torchaudio.functional  # noqa: F401
-import torchaudio.models  # noqa: F401
-import torchaudio.pipelines  # noqa: F401
-import torchaudio.sox_effects  # noqa: F401
-import torchaudio.transforms  # noqa: F401
-import torchaudio.utils  # noqa: F401
+def base_smoke_test():
+    import torchaudio  # noqa: F401
+    import torchaudio.compliance.kaldi  # noqa: F401
+    import torchaudio.datasets  # noqa: F401
+    import torchaudio.functional  # noqa: F401
+    import torchaudio.models  # noqa: F401
+    import torchaudio.pipelines  # noqa: F401
+    import torchaudio.sox_effects  # noqa: F401
+    import torchaudio.transforms  # noqa: F401
+    import torchaudio.utils  # noqa: F401
 
 
 def ffmpeg_test():
@@ -18,14 +20,25 @@ def ffmpeg_test():
 
 
 def main() -> None:
+    options = _parse_args()
+
+    if options.debug:
+        logging.basicConfig(format="%(levelname)s: %(message)s", level=logging.DEBUG)
+
+    base_smoke_test()
+    if options.ffmpeg:
+        ffmpeg_test()
+    print("Smoke test passed.")
+
+
+def _parse_args():
     parser = argparse.ArgumentParser()
 
     # Warning: Please note this option should not be widely used, only use it when absolutely necessary
     parser.add_argument("--no-ffmpeg", dest="ffmpeg", action="store_false")
+    parser.add_argument("--debug", action="store_true", help="Enable debug logging.")
 
-    options = parser.parse_args()
-    if options.ffmpeg:
-        ffmpeg_test()
+    return parser.parse_args()
 
 
 if __name__ == "__main__":