Initial lip-sync service with command backend

tests/test_backends.py

@@ -0,0 +1,110 @@
+from __future__ import annotations
+
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+from digital_human_lipsync_service.backends import (
+    LipSyncError,
+    quote_for_shell,
+    render_command_template,
+    run_command_backend,
+)
+from digital_human_lipsync_service.config import Settings
+
+
+def make_settings(tmp_path: Path, command_template: str) -> Settings:
+    output_dir = tmp_path / "outputs"
+    work_dir = tmp_path / "work"
+    output_dir.mkdir()
+    work_dir.mkdir()
+    return Settings(
+        host="127.0.0.1",
+        port=7860,
+        share=False,
+        backend="command",
+        ffmpeg="ffmpeg",
+        output_dir=output_dir,
+        work_dir=work_dir,
+        command_cwd=work_dir,
+        command_template=command_template,
+        command_timeout_seconds=10,
+        concurrency_limit=1,
+    )
+
+
+class CommandBackendTests(unittest.TestCase):
+    def test_render_command_template_supports_raw_and_quoted_paths(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            root = Path(tmp)
+            settings = make_settings(root, "model --audio {audio} --face {video_q} --out {output_q} --cwd {cwd}")
+            audio = root / "input audio.wav"
+            video = root / "input video.mp4"
+            output = root / "out video.mp4"
+
+            command = render_command_template(settings, audio, video, output)
+
+            self.assertIn(str(audio), command)
+            self.assertIn("input video.mp4", command)
+            self.assertIn("out video.mp4", command)
+            self.assertIn(str(settings.command_cwd), command)
+
+    def test_render_command_template_rejects_unknown_variable(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            root = Path(tmp)
+            settings = make_settings(root, "model --bad {missing}")
+
+            with self.assertRaisesRegex(LipSyncError, "Unknown LIPSYNC_COMMAND_TEMPLATE variable"):
+                render_command_template(settings, root / "a.wav", root / "v.mp4", root / "o.mp4")
+
+    def test_run_command_backend_reports_exit_code_and_stderr_tail(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            root = Path(tmp)
+            script = root / "fail_backend.py"
+            script.write_text(
+                "import sys\n"
+                "sys.stderr.write('api_key=super-secret\\nmodel failed near frame 12\\n')\n"
+                "raise SystemExit(7)\n",
+                encoding="utf-8",
+            )
+            settings = make_settings(root, f"{quote_for_shell(sys.executable)} {quote_for_shell(script)}")
+            audio = root / "a.wav"
+            video = root / "v.mp4"
+            output = root / "out.mp4"
+            audio.write_bytes(b"audio")
+            video.write_bytes(b"video")
+
+            with self.assertRaises(LipSyncError) as context:
+                run_command_backend(settings, audio, video, output)
+
+            message = str(context.exception)
+            self.assertIn("exit_code=7", message)
+            self.assertIn("model failed near frame 12", message)
+            self.assertIn("api_key=***", message)
+            self.assertNotIn("super-secret", message)
+
+    def test_run_command_backend_accepts_non_empty_output_file(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            root = Path(tmp)
+            script = root / "ok_backend.py"
+            script.write_text(
+                "import pathlib, sys\n"
+                "pathlib.Path(sys.argv[1]).write_bytes(b'fake mp4')\n",
+                encoding="utf-8",
+            )
+            settings = make_settings(root, f"{quote_for_shell(sys.executable)} {quote_for_shell(script)} {{output_q}}")
+            audio = root / "a.wav"
+            video = root / "v.mp4"
+            output = root / "out.mp4"
+            audio.write_bytes(b"audio")
+            video.write_bytes(b"video")
+
+            result = run_command_backend(settings, audio, video, output)
+
+            self.assertEqual(output, result)
+            self.assertGreater(output.stat().st_size, 0)
+
+
+if __name__ == "__main__":
+    unittest.main()