Microservice test strategy

Test cases should be prepared by Automation QA but, Component and contract tests should be written by developers and reviewed by QAs.
Component tests should simulate validation the same way a developer does during debugging, for example checking what data is sent in the event, what data is saved to the database, etc…
E2E tests should be written by developers.

Unit tests

Unit tests are optional

What to cover

Cover complex logic

When to run

Run in the pipeline

Integration tests (test-only integration)

Tests optional, could be written to run manually to check that integration works

What to cover

Integration with external dependencies
Repositories
HTTP Clients

When to run

Run locally, run manually during development, and remove after

Component tests

Out-of-process component tests

In a microservices architecture, a component can be a single microservice itself.

Use LightBDD testing framework to create human-readable scenarios
Developers should mock external services HTTP clients using WireMock .NET
Use local database hosted in docker, test database migrations
Run tests using Microsoft Test server integration testing framework.
Use in-memory mock for message bus.

What to cover

Automate manual test scenarios

When to run

Run in the pipeline

In-process component tests

Developers should mock everything inside the controller
Developers should cover authorization attributes and claims
Developers should cover model validation and binding

What to cover

Test request validations and Authentication attributes

When to run

should run in the pipeline

Contract tests

Developers should cover internal microservices HTTP clients pact
Developers should cover events contracts, pact messaging can be used

When to run

should run in an independent pipeline, all microservices should check to verify compatibility

E2E tests (integrations+configurations testing)

Test that the application started and run

Test database health check
Test External system HttpClient (call health checks)
Run a simple smoke test for the main flow in the microservice

Resources