In part 1, I showed how you can start using TDD when writing Drupal code, and how to apply it to testing a custom file validation callback. In part 2, we tackled testing the form building. In this part, I'll show how you can test the form validation.
I also decided to shoot a quick bonus video with a functional test, to demonstrate the difference in time execution. Food for thought: in our particular example, the functional tests take ~300x longer than the unit tests, without adding any more value. As I mention towards the end, you could probably get that down to “only” 60x times longer, at the cost of maintainability.
- Part 1.
- Part 2.
- Part 4.
- The source code for the example.
- The Composer template for Drupal project used for the project structure.
- The official documentation for writing automated tests in Drupal 8.
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