Database Integration Tests with Docker Sidecar in Jenkins

More often than not, developers want to test the source code against a real database instead of Fakes or Test Doubles during a CI job in order to verify the code works as expected. Therefore a clean database is needed for every CI-job. One solution is to use a shared instance of the database in your existing test-environment which get cleaned before and after a job. But this suffers from being “shared” and you never can run multiple CI-jobs in parallel without jobs interfering with each other....

May 9, 2021 · 2 min · Daniel Gerlach

Google Testing Toilet Collection

In my one of my previous posts i wrote about Good Unit Tests. During my research i discovered the famous Google Testing on the Toilet posts which provide great advice. The Testing-on-the-Toilet articles are short (~3min reads) and give hands-on examples, ready to be applied immediately. Here are my favorites: Testing on the Toilet Tests Too DRY? Make Them DAMP! Exercise Service Call Contracts in Tests...

May 23, 2020 · 2 min · Daniel Gerlach

Why and How to write better Unit Tests

TL;DR Good unit tests build the foundation of a maintainable and high-quality codebase Unit Tests should help developers to be productive Unit Tests should be fast Unit Tests should be isolated Unit Tests should be deterministic Unit Tests should focus on a single unit Unit Tests should be enduring Unit Tests should be clear, concise and complete Avoid complex control flow logic like nested ifs or loops Unit Tests should follow a consistent naming pattern like UnitName_StateUnderTest_ExpectedBehavior Unit Tests should comply to a consistent structure Unit Tests should be DAMP not DRY Unit Tests should give developers confidence to deploy and to refactor Test Doubles help to make tests fast and deterministic The overuse of Mocking makes test hard to read and brittle Prefer state verification over interaction verification Prevent brittle tests Prevent flaky tests Read more: Software Engineering at Google Kent Becks’s Programmer Test Principles Microsoft’s Best Practices for Unit testing Why good unit tests are important TDD and test engineering culture is considered best practice these days....

May 4, 2020 · 20 min · Daniel Gerlach