Refactor code structure for improved readability and maintainability

tests/test_api.py

@@ -6,26 +6,56 @@ import pytest
 
 from yt_shorts_downloader import api
 from yt_shorts_downloader.exceptions import InvalidSessionError, InvalidUrlError
-from yt_shorts_downloader.models import SessionValidation
+from yt_shorts_downloader.models import DownloadedVideo, SessionValidation
 
 
-def test_download_returns_path_from_downloader(
+def _build_valid_session_validation(path: Path) -> SessionValidation:
+    return SessionValidation(True, True, True, True, str(path))
+
+
+def test_download_returns_binary_mp4(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    expected_content = b"mp4-binary-content"
+
+    def fake_validate_session_file(path: Path) -> SessionValidation:
+        return _build_valid_session_validation(path)
+
+    def fake_download_video(*, url: str, output_dir: Path, session_path: Path) -> Path:
+        del url, session_path
+        downloaded_file = output_dir / "video.mp4"
+        downloaded_file.write_bytes(expected_content)
+        return downloaded_file
+
+    monkeypatch.setattr(api, "validate_session_file", fake_validate_session_file)
+    monkeypatch.setattr(api, "download_video", fake_download_video)
+
+    downloaded_video = api.download(
+        "https://youtube.com/shorts/example",
+        session_path="cookies.txt",
+    )
+
+    assert downloaded_video == DownloadedVideo(
+        filename="video.mp4",
+        content=expected_content,
+    )
+
+
+def test_download_to_path_returns_path_from_downloader(
     monkeypatch: pytest.MonkeyPatch, tmp_path: Path
 ) -> None:
     expected_path = tmp_path / "video.mp4"
 
-    monkeypatch.setattr(
-        api,
-        "validate_session_file",
-        lambda path: SessionValidation(True, True, True, True, str(path)),
-    )
-    monkeypatch.setattr(
-        api,
-        "download_video",
-        lambda *, url, output_dir, session_path: expected_path,
-    )
+    def fake_validate_session_file(path: Path) -> SessionValidation:
+        return _build_valid_session_validation(path)
 
-    downloaded_path = api.download(
+    def fake_download_video(*, url: str, output_dir: Path, session_path: Path) -> Path:
+        del url, session_path
+        expected_path.write_bytes(b"mp4")
+        return output_dir / expected_path.name
+
+    monkeypatch.setattr(api, "validate_session_file", fake_validate_session_file)
+    monkeypatch.setattr(api, "download_video", fake_download_video)
+
+    downloaded_path = api.download_to_path(
         "https://youtube.com/shorts/example",
         session_path="cookies.txt",
         output_dir=tmp_path,
@@ -40,11 +70,11 @@ def test_download_rejects_invalid_url() -> None:
 
 
 def test_download_rejects_invalid_session(monkeypatch: pytest.MonkeyPatch) -> None:
-    monkeypatch.setattr(
-        api,
-        "validate_session_file",
-        lambda path: SessionValidation(False, False, False, False, "bad session"),
-    )
+    def fake_validate_session_file(path: Path) -> SessionValidation:
+        del path
+        return SessionValidation(False, False, False, False, "bad session")
+
+    monkeypatch.setattr(api, "validate_session_file", fake_validate_session_file)
 
     with pytest.raises(InvalidSessionError, match="bad session"):
         api.download("https://youtube.com/shorts/example", session_path="cookies.txt")