add brain

.brain/.agent/skills/custom-skills/GenerateTest/IntegrationTest.md

@@ -0,0 +1,34 @@
+---
+name: GenerateIntegrationTest
+description: Guide to creating Integration Tests (end-to-end) using WebApplicationFactory and Testcontainers.
+---
+
+# GenerateIntegrationTest Skill
+
+When a user requests to create an **Integration Test** to verify API endpoints from start to finish, you need to generate the code according to the following guidelines:
+
+## Purpose
+- Test whether the assembled components work correctly together.
+- Flow: Client calls API -> Middleware -> Controller -> CQRS Handler/Service -> Read/Write to a real Database.
+
+## Implementation Guide
+1. **Setup WebApplicationFactory:**
+   - Automatically setup `WebApplicationFactory<Program>` (to create an in-memory test server in .NET).
+   - Override application configurations if necessary (e.g., changing the ConnectionString to point to a test container).
+
+2. **Setup Testcontainers (Real Database):**
+   - Use the `Testcontainers` library (or similar configuration) to automatically spin up a Docker container containing a real Database (e.g., PostgreSQL, SQL Server).
+   - Ensure this database container starts before the tests run and is automatically disposed of after the tests complete. Avoid using in-memory SQLite because it often causes minor bugs and does not accurately mimic a production database.
+
+3. **Write API Test Scenarios (Arrange - Act - Assert):**
+   - Create an `HttpClient` object from `WebApplicationFactory.CreateClient()`.
+   - **Arrange:** Prepare payload data as JSON objects or prepopulate database records for GET/PUT/DELETE APIs.
+   - **Act:** Call the corresponding API endpoint directly via code. E.g.: `await client.PostAsJsonAsync("/api/v1/samples", payload);`.
+   - **Assert:** Verify the returned results:
+     - Check HTTP Status: is it `200 OK` or `400 Bad Request`?
+     - Deserialize the response body to check the exact object data.
+     - (Optional) Query the database container directly to confirm the record was actually created/updated.
+
+## Output File Format
+- **Path:** Placed in the corresponding test project, such as `tests/MyNewProjectName.IntegrationTests/Controllers/...`.
+- **File Name:** `[ControllerName]Tests.cs` (e.g., `OrdersControllerTests.cs`).