integration-test-author

name	integration-test-author
description	Guide for authoring integration tests for minimal API endpoints using WebApplicationFactory, authenticated HttpClient, and repository-backed persistence. Use this when asked to write endpoint tests, HttpClient tests, or fixture-based integration tests.

Integration Test Author

Overview

This skill teaches how to write endpoint integration tests that follow this repository's patterns. It focuses on WebApplicationFactory, shared fixtures, authenticated HttpClient, and persistence readiness.

When to Use This Skill

• You add or change a minimal API endpoint.
• You change endpoint request or response contracts.
• You change authorization or authentication for endpoints.
• You want to verify validation responses and problem details.

When NOT to Use This Skill

• You are writing domain or application unit tests.
• You are testing handlers or validators without HTTP.

Prerequisites

• Integration test project exists.
• WebApplicationFactory is available.
• Endpoint test fixture is available.

Instructions

Step 1: Use the Fixture Pattern

Use the shared collection fixture that manages WebApplicationFactory, HttpClient, and authentication.

Reference: tests/Modules/CoreModule/CoreModule.IntegrationTests/Presentation/Web/EndpointTestFixture.cs

Step 2: Configure Auth Once

Configure auth options in the test constructor and attach output logging.

Reference: tests/Modules/CoreModule/CoreModule.IntegrationTests/Presentation/Web/CustomerEndpointTests.cs

Step 3: Seed Data via HTTP

Prefer seeding via HTTP POST so the test remains black-box and exercises full pipeline.

Step 4: Make Requests and Assert

• Assert HTTP status codes.
• Assert key fields in the response body.
• Deserialize to the expected model and assert properties.

Step 5: Cover Negative Paths

• 404 for missing resources.
• 400 for validation errors.
• 401 or 403 for auth failures if applicable.

Templates

• ./templates/EndpointTestFixtureUsageTemplate.cs
• ./templates/EndpointCrudTestsTemplate.cs
• ./templates/AuthZTestsTemplate.cs
• ./templates/SeedEntityHelperTemplate.cs

Examples

• ./examples/fixture-and-auth.md
• ./examples/customer-crud-endpoints.md
• ./examples/validation-problem-details.md
• ./examples/db-readiness.md

Checklists

• ./checklists/test-structure.md
• ./checklists/assertions.md
• ./checklists/flakiness.md
• ./checklists/auth.md

Common Pitfalls

WRONG: Making requests before the fixture is initialized and authenticated. CORRECT: Attach output and configure options in the constructor before making requests.

WRONG: Asserting only on raw JSON strings. CORRECT: Assert status codes and deserialize into the model for property assertions.

WRONG: Seeding through internal services without a good reason. CORRECT: Seed via HTTP POST to keep the test black-box.

WRONG: Ignoring database readiness and causing flaky tests. CORRECT: Rely on the fixture to wait for readiness before running requests.

References

• tests/Modules/CoreModule/CoreModule.IntegrationTests/Presentation/Web/EndpointTestFixture.cs
• tests/Modules/CoreModule/CoreModule.IntegrationTests/Presentation/Web/CustomerEndpointTests.cs