feat(music-lab): cover.py Pexels 이미지 검색 분기 (image_source=pexels)

music-lab/tests/test_cover_generation.py

@@ -91,3 +91,59 @@ async def test_dalle_b64_response_handled(tmp_storage, monkeypatch):
                                 prompt_template="x", mood="", track_title="X")
     assert out["used_fallback"] is False
     assert (tmp_storage / "46" / "cover.jpg").exists()
+
+
+@pytest.mark.asyncio
+@respx.mock
+async def test_pexels_image_source(tmp_storage, monkeypatch):
+    monkeypatch.setenv("PEXELS_API_KEY", "test-pexels-key")
+    img_url = "https://images.pexels.com/photos/123/photo.jpg"
+    respx.get("https://api.pexels.com/v1/search").mock(
+        return_value=Response(200, json={
+            "photos": [{
+                "id": 123,
+                "src": {"large2x": img_url, "original": img_url},
+            }],
+        })
+    )
+    png_bytes = bytes.fromhex(
+        "89504e470d0a1a0a0000000d49484452000000010000000108020000009077"
+        "53de0000000c4944415478da6300010000050001"
+        "0d0a2db40000000049454e44ae426082"
+    )
+    respx.get(img_url).mock(return_value=Response(200, content=png_bytes))
+
+    out = await cover.generate(
+        pipeline_id=99, genre="lo-fi", prompt_template="ignored",
+        mood="chill", track_title="Mix",
+        image_source="pexels",
+    )
+    assert out["used_fallback"] is False
+    assert out["url"].endswith("/cover.jpg")
+    assert (tmp_storage / "99" / "cover.jpg").exists()
+
+
+@pytest.mark.asyncio
+async def test_pexels_no_api_key_falls_back(tmp_storage, monkeypatch):
+    monkeypatch.delenv("PEXELS_API_KEY", raising=False)
+    out = await cover.generate(
+        pipeline_id=98, genre="lo-fi", prompt_template="x",
+        mood="", track_title="Test",
+        image_source="pexels",
+    )
+    assert out["used_fallback"] is True
+
+
+@pytest.mark.asyncio
+@respx.mock
+async def test_pexels_zero_results_falls_back(tmp_storage, monkeypatch):
+    monkeypatch.setenv("PEXELS_API_KEY", "test-key")
+    respx.get("https://api.pexels.com/v1/search").mock(
+        return_value=Response(200, json={"photos": []})
+    )
+    out = await cover.generate(
+        pipeline_id=97, genre="lo-fi", prompt_template="x",
+        mood="", track_title="Test",
+        image_source="pexels",
+    )
+    assert out["used_fallback"] is True