I'm like a test unitarian. Unit tests? Great. Integration tests? Awesome. End to end tests? If you're into that kind of thing, go for it. Coverage of lines of code doesn't matter. Coverage of critical business functions does. I think TDD can be a cult, but writing software that way for a little bit is a good training exercise.
I'm a senior engineer at a small startup. We need to move fast, ship new stuff fast, and get things moving. We've got CICD running mocked unit tests, integration tests, and end to end tests, with patterns and tooling for each.
I have support from the CTO in getting more testing in, and I'm able to use testing to cover bugs and regressions, and there's solid testing on a few critical user path features. However, I get resistance from the team on getting enough testing to prevent regressions going forward.
The resistance is usually along lines like:
- You shouldn't have to refactor to test something
- We shouldn't use mocks, only integration testing works.
- Repeat for test types N and M
- We can't test yet, we're going to make changes soon.
How can I convince the team that the tools available to them will help, and will improve their productivity and cut down time having to firefight?
This could be a good opportunity to introduce the concept of test-driven development (TDD) without the necessity to “write tests first”. But I think it can help illustrate why having tests is better when you are expecting to make changes because of the safety they provide.
“When we make those changes, wouldn’t it be great to have more confidence that the business logic didn’t break when adding a new technical capability?”
This seems like a reasonable statement and I sort of agree, in the sense that for existing production code, making a code change which only adds new tests yet also requires refactoring of existing functionality might feel a bit risky. As other commenters mentioned, starting with writing tests for new features or fixes might help prevent folks feeling like they are refactoring to test. Instead they’re refactoring and developing for the feature and the tests feel like they contribute to that feature as well.
I doubt that by now the concept of TDD is unheard of to any professional team. Name-dropping concepts actually contributes to loose credibility of any code quality effort, and works against you.
Also, TDD's credibility is already low as it piles on the requirement of spending unordinate amounts of extra work effort on aspects of a project which don't deliver features, and thus it's value-added is questionable from a project management perspective.
One aspect that does work is framing the need for tests as assurance that specific invariants are verified and preserved, and thus they contribute to prevent regressions and expected failure modes. From my experience it's far easier to sell the need for specific tests if they are framed as "we need assurances that this component does not fail under conceivable usecases" and specially as "we were screwed by this bug and we need to be absolutely sure we don't experience it ever again."
Agreed - this is the specific aspect which I hoped would be communicated by studying TDD a bit!
The team is afraid that making changes will be more difficult when tests exist, but TDD (or maybe a more specific concept like you mentioned) demonstrates that tests make future changes easier.
And I specifically advocated not to follow “write tests first”.
OK. If I were having an in-depth discussion with my team of fellow developers to convince them to start writing tests, I don’t think that’s name-dropping.
I think the best thing to do with TDD is pair with or convince devs to try it for a feature. Coming at things test first can be novel and interesting, and it does train you to test and use tests better. Once people have tried it, I think it broadens your use of tests pretty well.
However, TDD can be a bit of a cult, and most smart and independent people (like people willing to work at a <20 person company) will notice that TDD isn't the silver bullet it's proponents make it out to be.