fix(wtf_transcribe): resolve audio extensions without the OS MIME table

conserver/links/wtf_transcribe/__init__.py

@@ -26,6 +26,7 @@
 import json
 import logging
 import mimetypes
+import os
 import requests
 from typing import Optional, Dict, Any
 
@@ -181,6 +182,23 @@ def dialog_to_audio_binary(dialog, url_timeout):
 def dialog_filename(dialog, dialog_index):
     return dialog.get("filename", f"audio_{dialog_index}.wav")
 
+# Common audio/video extensions, checked before the OS MIME table: slim Linux
+# images ship without /etc/mime.types, where mimetypes.guess_type("x.ogg")
+# returns None even though macOS resolves it.
+_MEDIA_EXTENSIONS = {
+    ".wav": "audio/wav",
+    ".mp3": "audio/mpeg",
+    ".ogg": "audio/ogg",
+    ".oga": "audio/ogg",
+    ".opus": "audio/opus",
+    ".m4a": "audio/mp4",
+    ".aac": "audio/aac",
+    ".flac": "audio/flac",
+    ".webm": "audio/webm",
+    ".mp4": "video/mp4",
+}
+
+
 def dialog_mediatype(dialog):
     """Resolve a dialog's media type.
 
@@ -199,6 +217,9 @@ def dialog_mediatype(dialog):
 
     filename = dialog.get("filename")
     if filename:
+        known = _MEDIA_EXTENSIONS.get(os.path.splitext(filename)[1].lower())
+        if known:
+            return known
         guessed_type, _ = mimetypes.guess_type(filename)
         if guessed_type and (guessed_type.startswith("audio/") or guessed_type.startswith("video/")):
             return guessed_type

conserver/links/wtf_transcribe/test_wtf_transcribe_unit.py

@@ -239,3 +239,15 @@ def test_run_happy_path_installs_defaults_and_saves(
         url_timeout=60,
     )
     mock_save_vcon.assert_called_once_with(vcon, redis)
+
+
+def test_dialog_mediatype_extension_table_without_os_mime_table(monkeypatch):
+    # Slim Linux images have no /etc/mime.types, so guess_type() knows little.
+    # The built-in extension table must still resolve common audio types.
+    import links.wtf_transcribe as wtf
+
+    monkeypatch.setattr(wtf.mimetypes, "guess_type", lambda *_a, **_k: (None, None))
+    assert wtf.dialog_mediatype({"filename": "clip.ogg"}) == "audio/ogg"
+    assert wtf.dialog_mediatype({"filename": "CALL.MP3"}) == "audio/mpeg"
+    assert wtf.dialog_mediatype({"filename": "x.opus"}) == "audio/opus"
+    assert wtf.dialog_mediatype({"filename": "notes.txt"}) == "audio/wav"