fixes incomplete yt-dlp parts download

tests/test_metadata.py

@@ -86,6 +86,22 @@ def test_media_management(basic_metadata, media_file):
     assert basic_metadata.get_media_by_id("m1") == media1
 
 
+def test_remove_duplicate_skips_missing_files(basic_metadata, media_file, tmp_path):
+    """Missing files should be dropped instead of crashing with FileNotFoundError."""
+    real_file = tmp_path / "exists.txt"
+    real_file.write_text("content")
+    valid = media_file(filename=str(real_file), hash_value="abc")
+    missing = media_file(filename="/nonexistent/path/gone.mp4")
+
+    basic_metadata.add_media(valid, "valid")
+    basic_metadata.add_media(missing, "missing")
+
+    assert len(basic_metadata.media) == 2
+    basic_metadata.remove_duplicate_media_by_hash()
+    assert len(basic_metadata.media) == 1
+    assert basic_metadata.get_media_by_id("valid") == valid
+
+
 def test_success():
     m = Metadata()
     assert not m.is_success()

tests/utils/test_misc.py

@@ -14,6 +14,7 @@ from auto_archiver.utils.misc import (
     calculate_file_hash,
     random_str,
     get_timestamp,
+    ydl_entry_to_filename,
 )
 
 
@@ -139,3 +140,47 @@ class TestMiscUtils:
 
     def test_invalid_timestamp_returns_none(self):
         assert get_timestamp("invalid-date") is None
+
+
+class TestYdlEntryToFilename:
+    """Tests for ydl_entry_to_filename, especially .part file filtering."""
+
+    def _make_mock_ydl(self, prepared_filename):
+        class MockYDL:
+            def prepare_filename(self, entry):
+                return prepared_filename
+
+        return MockYDL()
+
+    def test_returns_exact_file_if_exists(self, tmp_path):
+        video = tmp_path / "video.mp4"
+        video.write_bytes(b"data")
+        ydl = self._make_mock_ydl(str(video))
+        assert ydl_entry_to_filename(ydl, {}) == str(video)
+
+    def test_skips_part_file_returns_complete(self, tmp_path):
+        """Simulates yt-dlp leaving a .part file from a failed format
+        while a complete .webm exists."""
+        (tmp_path / "f5U3IKfoSYs.f399.mp4.part").write_bytes(b"incomplete")
+        webm = tmp_path / "f5U3IKfoSYs.webm"
+        webm.write_bytes(b"complete video")
+
+        # ydl.prepare_filename returns the expected .mp4 which doesn't exist
+        ydl = self._make_mock_ydl(str(tmp_path / "f5U3IKfoSYs.mp4"))
+        result = ydl_entry_to_filename(ydl, {})
+
+        assert result == str(webm)
+        assert not result.endswith(".part")
+
+    def test_skips_part_file_returns_false_if_no_other_match(self, tmp_path):
+        """Only a .part file exists — should return False."""
+        (tmp_path / "video.f399.mp4.part").write_bytes(b"incomplete")
+
+        ydl = self._make_mock_ydl(str(tmp_path / "video.mp4"))
+        assert ydl_entry_to_filename(ydl, {}) is False
+
+    def test_returns_false_when_no_files_match(self, tmp_path):
+        (tmp_path / "unrelated.txt").write_bytes(b"data")
+
+        ydl = self._make_mock_ydl(str(tmp_path / "video.mp4"))
+        assert ydl_entry_to_filename(ydl, {}) is False