feat(converter): add per-chapter and m4b output

1 files changed, 44 insertions, 2 deletions

diff --git a/tests/test_audio.py b/tests/test_audio.py
index a629224..29bf4ea 100644
--- a/tests/test_audio.py
+++ b/tests/test_audio.py
@@ -1,11 +1,11 @@
-"""Tests for audio helpers: speed parameters and chunk cleanup."""
+"""Tests for audio helpers: speed parameters, chunk cleanup, and encoding."""
 
 import tempfile
 import unittest
 from pathlib import Path
 
 from converter import config
-from converter.audio import cleanup_chunks, speed_export_params
+from converter.audio import _encode_args, build_ffmetadata, cleanup_chunks, speed_export_params
 
 
 class SpeedExportParamsTests(unittest.TestCase):
@@ -52,6 +52,48 @@ class CleanupChunksTests(unittest.TestCase):
             self.assertFalse((chunks_dir / "chunk_0002.wav").exists())
             self.assertTrue((chunks_dir / "keep.txt").exists())
 
+    def test_removes_chapter_files(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            chunks_dir = Path(tmp)
+            (chunks_dir / "chapter_0001.m4b").write_bytes(b"stale")
+            (chunks_dir / "chunk_0001.wav").write_bytes(b"stale")
+
+            original = config.CHUNKS_FOLDER
+            config.CHUNKS_FOLDER = chunks_dir
+            try:
+                cleanup_chunks()
+            finally:
+                config.CHUNKS_FOLDER = original
+
+            self.assertFalse((chunks_dir / "chapter_0001.m4b").exists())
+            self.assertFalse((chunks_dir / "chunk_0001.wav").exists())
+
+
+class EncodeArgsTests(unittest.TestCase):
+    def test_mp3_uses_bitrate_only(self):
+        self.assertEqual(_encode_args("mp3"), ["-b:a", config.AUDIO_BITRATE])
+
+    def test_m4b_uses_aac(self):
+        self.assertEqual(_encode_args("m4b"), ["-c:a", "aac", "-b:a", config.AUDIO_BITRATE])
+
+
+class BuildFFMetadataTests(unittest.TestCase):
+    def test_writes_chapters(self):
+        chapters = [(0, 1200, "One"), (1200, 2500, "Two")]
+        with tempfile.TemporaryDirectory() as tmp:
+            path = Path(tmp) / "meta.txt"
+            build_ffmetadata(chapters, path)
+            content = path.read_text(encoding="utf-8")
+
+        self.assertTrue(content.startswith(";FFMETADATA1\n"))
+        self.assertIn("[CHAPTER]", content)
+        self.assertIn("TIMEBASE=1/1000", content)
+        self.assertIn("START=0", content)
+        self.assertIn("END=1200", content)
+        self.assertIn("title=One", content)
+        self.assertIn("START=1200", content)
+        self.assertIn("title=Two", content)
+
 
 if __name__ == "__main__":
     unittest.main()