Refactor code style and improve documentation

- Standardized string quotes to single quotes across all files.
- Added docstrings to several functions and classes for better clarity.
- Updated mypy configuration in pyproject.toml for enhanced type checking.
- Ignored specific linting rules for test files in ruff configuration.
- Improved error messages in exception handling for better user feedback.
- Cleaned up code formatting and structure for consistency.

tests/test_api.py

@@ -14,50 +14,48 @@ def _build_valid_session_validation(path: Path) -> SessionValidation:
 
 
 def test_download_returns_binary_mp4(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
-    expected_content = b"mp4-binary-content"
+    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 = 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)
+    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",
+        'https://youtube.com/shorts/example',
+        session_path='cookies.txt',
     )
 
     assert downloaded_video == DownloadedVideo(
-        filename="video.mp4",
+        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"
+def test_download_to_path_returns_path_from_downloader(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    expected_path = tmp_path / 'video.mp4'
 
     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
-        expected_path.write_bytes(b"mp4")
+        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)
+    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",
+        'https://youtube.com/shorts/example',
+        session_path='cookies.txt',
         output_dir=tmp_path,
     )
 
@@ -66,15 +64,15 @@ def test_download_to_path_returns_path_from_downloader(
 
 def test_download_rejects_invalid_url() -> None:
     with pytest.raises(InvalidUrlError):
-        api.download("https://example.com/watch?v=1", session_path="cookies.txt")
+        api.download('https://example.com/watch?v=1', session_path='cookies.txt')
 
 
 def test_download_rejects_invalid_session(monkeypatch: pytest.MonkeyPatch) -> None:
     def fake_validate_session_file(path: Path) -> SessionValidation:
         del path
-        return SessionValidation(False, False, False, False, "bad session")
+        return SessionValidation(False, False, False, False, 'bad session')
 
-    monkeypatch.setattr(api, "validate_session_file", fake_validate_session_file)
+    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")
+    with pytest.raises(InvalidSessionError, match='bad session'):
+        api.download('https://youtube.com/shorts/example', session_path='cookies.txt')

tests/test_cli.py

@@ -13,19 +13,19 @@ def test_cli_prints_downloaded_path(
     capsys: pytest.CaptureFixture[str],
     tmp_path: Path,
 ) -> None:
-    expected_path = tmp_path / "video.mp4"
+    expected_path = tmp_path / 'video.mp4'
 
     def fake_download_to_path(**kwargs: object) -> Path:
         del kwargs
         return expected_path
 
-    monkeypatch.setattr(cli, "download_to_path", fake_download_to_path)
+    monkeypatch.setattr(cli, 'download_to_path', fake_download_to_path)
 
     exit_code = cli.main(
         [
-            "https://youtube.com/shorts/example",
-            "cookies.txt",
-            "--output-dir",
+            'https://youtube.com/shorts/example',
+            'cookies.txt',
+            '--output-dir',
             str(tmp_path),
         ]
     )
@@ -39,11 +39,11 @@ def test_cli_prints_downloaded_path(
 def test_cli_exits_with_error(monkeypatch: pytest.MonkeyPatch) -> None:
     def raise_error(**kwargs: object) -> Path:
         del kwargs
-        raise InvalidSessionError("session error")
+        raise InvalidSessionError('session error')
 
-    monkeypatch.setattr(cli, "download_to_path", raise_error)
+    monkeypatch.setattr(cli, 'download_to_path', raise_error)
 
     with pytest.raises(SystemExit) as exc_info:
-        cli.main(["https://youtube.com/shorts/example", "cookies.txt"])
+        cli.main(['https://youtube.com/shorts/example', 'cookies.txt'])
 
     assert exc_info.value.code == 1

tests/test_runtime.py

@@ -12,39 +12,42 @@ def test_find_supported_js_runtimes_prefers_deno(
 ) -> None:
     monkeypatch.setattr(
         runtime,
-        "which",
-        lambda executable: "/usr/bin/deno" if executable == "deno" else None,
+        'which',
+        lambda executable: '/usr/bin/deno' if executable == 'deno' else None,
     )
 
     runtimes = runtime.find_supported_js_runtimes()
 
-    assert runtimes == {"deno": {"path": "/usr/bin/deno"}}
+    assert runtimes == {'deno': {'path': '/usr/bin/deno'}}
 
 
 def test_find_supported_js_runtimes_uses_best_supported_node(
     monkeypatch: pytest.MonkeyPatch,
     tmp_path: Path,
 ) -> None:
-    first_node = tmp_path / ".nvm" / "versions" / "node" / "v22.1.0" / "bin" / "node"
-    second_node = tmp_path / ".nvm" / "versions" / "node" / "v22.9.0" / "bin" / "node"
+    first_node = tmp_path / '.nvm' / 'versions' / 'node' / 'v22.1.0' / 'bin' / 'node'
+    second_node = tmp_path / '.nvm' / 'versions' / 'node' / 'v22.9.0' / 'bin' / 'node'
     second_node.parent.mkdir(parents=True)
     first_node.parent.mkdir(parents=True)
-    first_node.write_text("", encoding="utf-8")
-    second_node.write_text("", encoding="utf-8")
+    first_node.write_text('', encoding='utf-8')
+    second_node.write_text('', encoding='utf-8')
 
-    monkeypatch.setattr(runtime, "which", lambda executable: None)
-    monkeypatch.setattr(Path, "home", lambda: tmp_path)
+    def fake_which(_executable: str) -> None:
+        return None
+
+    monkeypatch.setattr(runtime, 'which', fake_which)
+    monkeypatch.setattr(Path, 'home', lambda: tmp_path)
     monkeypatch.setattr(
         runtime,
-        "_probe_executable_version",
-        lambda executable: (22, 9, 0) if executable.endswith("v22.9.0/bin/node") else (22, 1, 0),
+        '_probe_executable_version',
+        lambda executable: (22, 9, 0) if executable.endswith('v22.9.0/bin/node') else (22, 1, 0),
     )
 
     runtimes = runtime.find_supported_js_runtimes()
 
-    assert runtimes == {"node": {"path": str(second_node.resolve())}}
+    assert runtimes == {'node': {'path': str(second_node.resolve())}}
 
 
 def test_parse_semver_handles_prefixed_versions() -> None:
-    assert runtime._parse_semver("v22.12.1") == (22, 12, 1)
-    assert runtime._parse_semver("node") is None
+    assert runtime._parse_semver('v22.12.1') == (22, 12, 1)
+    assert runtime._parse_semver('node') is None

tests/test_session.py

@@ -6,17 +6,17 @@ from yt_shorts_downloader.session import validate_session_file
 
 
 def test_validate_session_file_accepts_valid_youtube_session(tmp_path: Path) -> None:
-    session_file = tmp_path / "cookies.txt"
+    session_file = tmp_path / 'cookies.txt'
     session_file.write_text(
-        "\n".join(
+        '\n'.join(
             [
-                "# Netscape HTTP Cookie File",
-                ".youtube.com\tTRUE\t/\tFALSE\t9999999999\tSID\tvalue1",
-                ".youtube.com\tTRUE\t/\tTRUE\t9999999999\tSAPISID\tvalue2",
-                ".youtube.com\tTRUE\t/\tTRUE\t9999999999\tLOGIN_INFO\tvalue3",
+                '# Netscape HTTP Cookie File',
+                '.youtube.com\tTRUE\t/\tFALSE\t9999999999\tSID\tvalue1',
+                '.youtube.com\tTRUE\t/\tTRUE\t9999999999\tSAPISID\tvalue2',
+                '.youtube.com\tTRUE\t/\tTRUE\t9999999999\tLOGIN_INFO\tvalue3',
             ]
         ),
-        encoding="utf-8",
+        encoding='utf-8',
     )
 
     validation = validate_session_file(session_file)
@@ -28,8 +28,8 @@ def test_validate_session_file_accepts_valid_youtube_session(tmp_path: Path) ->
 
 
 def test_validate_session_file_rejects_invalid_format(tmp_path: Path) -> None:
-    session_file = tmp_path / "cookies.txt"
-    session_file.write_text("broken\trow", encoding="utf-8")
+    session_file = tmp_path / 'cookies.txt'
+    session_file.write_text('broken\trow', encoding='utf-8')
 
     validation = validate_session_file(session_file)