LCORE-716: Refactor duplicate integration/endpoints tests to parameterized tests

tests/integration/README.md

@@ -10,6 +10,7 @@ This directory contains integration tests for Lightspeed Core Stack. Integration
 - [Test Constants](#test-constants)
 - [Writing Integration Tests](#writing-integration-tests)
 - [Running Tests](#running-tests)
+- [Data-Driven (Parameterized) Tests](#data-driven-parameterized-tests)
 - [Best Practices](#best-practices)
 
 ## Getting Started
@@ -252,6 +253,107 @@ uv run make test-integration
 uv run pytest tests/integration/ -v --tb=short
 ```
 
+## Data-Driven (Parameterized) Tests
+
+### Overview
+
+Data-driven tests use `@pytest.mark.parametrize` to run the same test logic with different inputs. This eliminates duplicate code and makes test coverage more visible.
+
+**Benefits:**
+- Reduce code duplication 
+- Add new test cases by simply adding to the data table
+- See all test scenarios at a glance
+- Consistent structure across similar tests
+
+### When to Use
+
+Use parameterized tests when you have:
+- **Multiple similar tests** that differ only in input data and expected output
+- **Validation tests** with multiple valid/invalid scenarios
+- **Error handling tests** with different error conditions
+
+### Pattern
+
+```python
+# Define test cases as a list
+TEST_CASES = [
+    pytest.param(
+        {
+            "input": "value1",
+            "expected_result": "result1",
+        },
+        id="descriptive_test_name_1",
+    ),
+    pytest.param(
+        {
+            "input": "value2",
+            "expected_result": "result2",
+        },
+        id="descriptive_test_name_2",
+    ),
+]
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("test_case", TEST_CASES)
+async def test_example_data_driven(
+    test_case: dict,
+    # ... fixtures
+) -> None:
+    """Data-driven test for example functionality.
+
+    Tests multiple scenarios:
+    - Scenario 1 description
+    - Scenario 2 description
+
+    Parameters:
+        test_case: Dictionary containing test parameters
+        # ... other fixtures
+    """
+    input_value = test_case["input"]
+    expected = test_case["expected_result"]
+
+    result = await function_under_test(input_value)
+
+    assert result == expected
+```
+
+### Best Practices for Parameterized Tests
+
+1. **Use descriptive `id` values** - They appear in test output
+   ```python
+   pytest.param(..., id="attachment_unknown_type_returns_422")  # Good
+   pytest.param(..., id="test1")  # Bad
+   ```
+
+2. **Group related test data** - Keep test cases together at module level
+   ```python
+   ATTACHMENT_TEST_CASES = [...]  # Define near the test that uses it
+   ```
+
+3. **Document all scenarios** - List scenarios in docstring
+   ```python
+   """Data-driven test for attachments.
+
+   Tests:
+   - Single attachment
+   - Empty payload
+   - Invalid type (422 error)
+   """
+   ```
+
+4. **Keep test logic simple** - Use if/else only for success vs. error paths
+   ```python
+   if expected_status == 200:
+       # Success assertions
+   else:
+       # Error assertions
+   ```
+
+5. **Use consistent dict keys** - Standardize parameter names
+   ```python
+   {"expected_status": 200, "expected_error": None}  # Consistent
+   ```
+
 ## Best Practices
 
 ### 1. Use Common Fixtures

tests/integration/endpoints/test_model_list.py

@@ -86,55 +86,61 @@ def mock_llama_stack_client_failing_fixture(
     yield mock_client
 
 
-@pytest.mark.asyncio
-async def test_models_list(
-    test_config: AppConfig,
-    mock_llama_stack_client: AsyncMockType,
-    test_request: Request,
-    test_auth: AuthTuple,
-) -> None:
-    """Test that models endpoint returns successful response.
-
-    This integration test verifies:
-    - Model list handler
-
-    Parameters:
-        test_config: Test configuration
-        mock_llama_stack_client: Mocked Llama Stack client
-        test_request: FastAPI request
-        test_auth: noop authentication tuple
-    """
-    _ = test_config
-    _ = mock_llama_stack_client
-
-    response = await models_endpoint_handler(
-        request=test_request,
-        auth=test_auth,
-        model_type=ModelFilter(model_type=None),
-    )
-
-    # Verify response structure
-    assert response is not None
-    assert len(response.models) == 2
-    assert response.models[0]["identifier"] == "test-provider/test-model-1"
-    assert response.models[0]["api_model_type"] == "llm"
-    assert response.models[1]["identifier"] == "test-provider/test-model-2"
-    assert response.models[1]["api_model_type"] == "embedding"
+MODEL_FILTER_TEST_CASES = [
+    pytest.param(
+        {
+            "filter_type": None,
+            "expected_count": 2,
+            "expected_models": [
+                {"identifier": "test-provider/test-model-1", "api_model_type": "llm"},
+                {
+                    "identifier": "test-provider/test-model-2",
+                    "api_model_type": "embedding",
+                },
+            ],
+        },
+        id="no_filter_returns_all_models",
+    ),
+    pytest.param(
+        {
+            "filter_type": "llm",
+            "expected_count": 1,
+            "expected_models": [
+                {"identifier": "test-provider/test-model-1", "api_model_type": "llm"},
+            ],
+        },
+        id="filter_llm_returns_llm_model",
+    ),
+    pytest.param(
+        {
+            "filter_type": "foobar",
+            "expected_count": 0,
+            "expected_models": [],
+        },
+        id="filter_unknown_type_returns_empty",
+    ),
+]
 
 
 @pytest.mark.asyncio
-async def test_models_list_filter_model_type_llm(
+@pytest.mark.parametrize("test_case", MODEL_FILTER_TEST_CASES)
+async def test_models_list_with_filter(
+    test_case: dict,
     test_config: AppConfig,
     mock_llama_stack_client: AsyncMockType,
     test_request: Request,
     test_auth: AuthTuple,
 ) -> None:
-    """Test that models endpoint returns successful response.
+    """Tests for models endpoint filtering.
 
-    This integration test verifies:
-    - Model list handler
+    Tests different model_type filter scenarios:
+    - No filter (returns all models)
+    - Filter by llm type
+    - Filter by unknown type (returns empty)
 
     Parameters:
+        test_case: Dictionary containing test parameters (filter_type,
+            expected_count, expected_models)
         test_config: Test configuration
         mock_llama_stack_client: Mocked Llama Stack client
         test_request: FastAPI request
@@ -143,81 +149,24 @@ async def test_models_list_filter_model_type_llm(
     _ = test_config
     _ = mock_llama_stack_client
 
-    response = await models_endpoint_handler(
-        request=test_request, auth=test_auth, model_type=ModelFilter(model_type="llm")
-    )
-
-    # Verify response structure
-    assert response is not None
-    assert len(response.models) == 1
-    assert response.models[0]["identifier"] == "test-provider/test-model-1"
-    assert response.models[0]["api_model_type"] == "llm"
-
-
-@pytest.mark.asyncio
-async def test_models_list_filter_model_type_embedding(
-    test_config: AppConfig,
-    mock_llama_stack_client: AsyncMockType,
-    test_request: Request,
-    test_auth: AuthTuple,
-) -> None:
-    """Test that models endpoint returns successful response.
-
-    This integration test verifies:
-    - Model list handler
-
-    Parameters:
-        test_config: Test configuration
-        mock_llama_stack_client: Mocked Llama Stack client
-        test_request: FastAPI request
-        test_auth: noop authentication tuple
-    """
-    _ = test_config
-    _ = mock_llama_stack_client
+    filter_type = test_case["filter_type"]
+    expected_count = test_case["expected_count"]
+    expected_models = test_case["expected_models"]
 
     response = await models_endpoint_handler(
         request=test_request,
         auth=test_auth,
-        model_type=ModelFilter(model_type="embedding"),
+        model_type=ModelFilter(model_type=filter_type),
     )
 
     # Verify response structure
     assert response is not None
-    assert len(response.models) == 1
-    assert response.models[0]["identifier"] == "test-provider/test-model-2"
-    assert response.models[0]["api_model_type"] == "embedding"
-
-
-@pytest.mark.asyncio
-async def test_models_list_filter_model_type_unknown(
-    test_config: AppConfig,
-    mock_llama_stack_client: AsyncMockType,
-    test_request: Request,
-    test_auth: AuthTuple,
-) -> None:
-    """Test that models endpoint returns successful response.
-
-    This integration test verifies:
-    - Model list handler
-
-    Parameters:
-        test_config: Test configuration
-        mock_llama_stack_client: Mocked Llama Stack client
-        test_request: FastAPI request
-        test_auth: noop authentication tuple
-    """
-    _ = test_config
-    _ = mock_llama_stack_client
-
-    response = await models_endpoint_handler(
-        request=test_request,
-        auth=test_auth,
-        model_type=ModelFilter(model_type="foobar"),
-    )
+    assert len(response.models) == expected_count
 
-    # Verify response structure
-    assert response is not None
-    assert len(response.models) == 0
+    # Verify each expected model
+    for i, expected_model in enumerate(expected_models):
+        assert response.models[i]["identifier"] == expected_model["identifier"]
+        assert response.models[i]["api_model_type"] == expected_model["api_model_type"]
 
 
 @pytest.mark.asyncio