test: raise gemini API client coverage to 90%

src/services/gemini_api_client.py

@@ -53,7 +53,7 @@ def __init__(
 
         logger.debug(f"GeminiAPIClient initialized: model={model_name}")
 
-    def send_multimodal_prompt(self, text: str, screenshot: Screenshot) -> str:  # noqa: PLR0912
+    def send_multimodal_prompt(self, text: str, screenshot: Screenshot) -> str:  # noqa: PLR0912, PLR0915
         """
         Send text + image prompt to Gemini API.
 
@@ -167,11 +167,13 @@ def send_multimodal_prompt(self, text: str, screenshot: Screenshot) -> str:  # n
         except genai.types.generation_types.BlockedPromptException as e:
             raise APIError(f"Prompt blocked by safety filters: {e}") from e
         except Exception as e:
-            if "API_KEY_INVALID" in str(e) or "invalid API key" in str(e).lower():
+            message = str(e)
+            message_lower = message.lower()
+            if "API_KEY_INVALID" in message or "invalid api key" in message_lower:
                 raise AuthenticationError("Invalid or expired Gemini API key") from e
-            if "quota" in str(e).lower():
+            if "quota" in message_lower:
                 raise APIError(f"API quota exceeded: {e}") from e
-            if "not found" in str(e).lower():
+            if "not found" in message_lower:
                 raise APIError(f"Model not found: {self.model_name}") from e
             raise APIError(f"Gemini API request failed: {e}") from e
 

tests/unit/test_gemini_api_client.py

@@ -10,7 +10,7 @@
 import pytest
 from PIL import Image
 
-from src.lib.exceptions import APIError, OAuthConfigNotFoundError, PayloadTooLargeError
+from src.lib.exceptions import APIError, AuthenticationError, OAuthConfigNotFoundError, PayloadTooLargeError
 from src.models.entities import Screenshot
 from src.services.gemini_api_client import GeminiAPIClient
 
@@ -64,6 +64,36 @@ def test_get_api_key_raises_when_no_sources_available(
         client._get_api_key()
 
 
+def test_get_api_key_reads_from_yaml_config(
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+) -> None:
+    cfg = tmp_path / "config.yaml"
+    cfg.write_text("gemini:\n  api_key: yaml-key\n", encoding="utf-8")
+    monkeypatch.delenv("GEMINI_API_KEY", raising=False)
+    monkeypatch.delenv("GOOGLE_API_KEY", raising=False)
+    monkeypatch.setattr(GeminiAPIClient, "DEFAULT_CONFIG_PATH", cfg)
+
+    client = GeminiAPIClient(api_key=None)
+
+    assert client._get_api_key() == "yaml-key"
+
+
+def test_validate_oauth_token_returns_false_on_unexpected_error(monkeypatch: pytest.MonkeyPatch) -> None:
+    client = GeminiAPIClient(api_key=None)
+    monkeypatch.setattr(client, "_get_api_key", lambda: (_ for _ in ()).throw(RuntimeError("boom")))
+
+    assert client.validate_oauth_token() is False
+
+
+def test_refresh_oauth_token_raises_when_validation_fails(monkeypatch: pytest.MonkeyPatch) -> None:
+    client = GeminiAPIClient(api_key=None)
+    monkeypatch.setattr(client, "validate_oauth_token", lambda: False)
+
+    with pytest.raises(AuthenticationError, match="API key is invalid and cannot be refreshed"):
+        client.refresh_oauth_token()
+
+
 def test_send_multimodal_prompt_missing_file_raises_api_error() -> None:
     client = GeminiAPIClient(api_key="gem-key")
     screenshot = Screenshot(
@@ -102,6 +132,37 @@ def test_send_multimodal_prompt_large_payload_raises(sample_screenshot: Screensh
         client.send_multimodal_prompt("hello", oversized)
 
 
+def test_send_multimodal_prompt_initializes_model_when_missing(
+    monkeypatch: pytest.MonkeyPatch,
+    sample_screenshot: Screenshot,
+) -> None:
+    client = GeminiAPIClient(api_key="gem-key")
+    monkeypatch.setattr("src.services.gemini_api_client.genai.configure", lambda **_kwargs: None)
+    monkeypatch.setattr(
+        "src.services.gemini_api_client.genai.GenerativeModel",
+        lambda **_kwargs: _FakeModel(
+            SimpleNamespace(
+                prompt_feedback=None,
+                candidates=[SimpleNamespace(content=SimpleNamespace(parts=[SimpleNamespace(text="ok")]))],
+            )
+        ),
+    )
+
+    assert client.send_multimodal_prompt("hello", sample_screenshot) == "ok"
+
+
+def test_send_multimodal_prompt_raises_when_model_init_returns_none(
+    monkeypatch: pytest.MonkeyPatch,
+    sample_screenshot: Screenshot,
+) -> None:
+    client = GeminiAPIClient(api_key="gem-key")
+    monkeypatch.setattr("src.services.gemini_api_client.genai.configure", lambda **_kwargs: None)
+    monkeypatch.setattr("src.services.gemini_api_client.genai.GenerativeModel", lambda **_kwargs: None)
+
+    with pytest.raises(APIError, match="Gemini model initialization failed"):
+        client.send_multimodal_prompt("hello", sample_screenshot)
+
+
 def test_send_multimodal_prompt_returns_concatenated_text(
     monkeypatch: pytest.MonkeyPatch,
     sample_screenshot: Screenshot,
@@ -153,3 +214,33 @@ def test_send_multimodal_prompt_raises_on_empty_candidates(
 
     with pytest.raises(APIError, match="No response candidates"):
         client.send_multimodal_prompt("hello", sample_screenshot)
+
+
+@pytest.mark.parametrize(
+    ("message", "exception_type", "expected"),
+    [
+        ("API_KEY_INVALID", AuthenticationError, "Invalid or expired Gemini API key"),
+        ("invalid API key", AuthenticationError, "Invalid or expired Gemini API key"),
+        ("quota exceeded", APIError, "API quota exceeded"),
+        ("model not found", APIError, "Model not found"),
+        ("other boom", APIError, "Gemini API request failed"),
+    ],
+)
+def test_send_multimodal_prompt_maps_runtime_errors(
+    monkeypatch: pytest.MonkeyPatch,
+    sample_screenshot: Screenshot,
+    message: str,
+    exception_type: type[Exception],
+    expected: str,
+) -> None:
+    client = GeminiAPIClient(api_key="gem-key")
+    monkeypatch.setattr("src.services.gemini_api_client.genai.configure", lambda **_kwargs: None)
+
+    class _RaiseModel:
+        def generate_content(self, *_args, **_kwargs):
+            raise RuntimeError(message)
+
+    client._model = _RaiseModel()
+
+    with pytest.raises(exception_type, match=expected):
+        client.send_multimodal_prompt("hello", sample_screenshot)