Comments on: Tips for Unit Testing

By: Doron

Doron — Mon, 14 Jul 2008 12:30:42 +0000

Nice tips, a good way to prevent beginners from early despair.

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By: Michael Easter

Michael Easter — Thu, 10 Jul 2008 16:10:16 +0000

Good stuff… however I want to amplify the point that automated testing is more than ‘unit’ testing.

We use dbUnit for integration testing of our Hibernate mappings and it has been a tremendous success. We migrated from an OODB to Postgres in a giant refactoring and dbUnit was vital to the effort.

By: Ben

Ben — Wed, 09 Jul 2008 14:25:37 +0000

@Greg - thanks for the book suggestion, I’ll check it out.

As always, I suspect it’s a balance. Some amount of DRYness in tests is probably a good thing (for instance a few helper methods for operations that really are universal).

However, if you push things too far, you start seeing things like fixtures and setup/teardown methods, which have good intentions, but I think many people have found to be very brittle. That’s why I try to keep my tests somewhere in the middle (AKA “moist”).

By: Reflective Perspective - Chris Alcock » The Morning Brew #132

Reflective Perspective - Chris Alcock » The Morning Brew #132 — Wed, 09 Jul 2008 07:14:06 +0000

[...] Tips for Unit Testing - Ben posts a collection of good tips on unit testing [...]

By: Greg

Greg — Wed, 09 Jul 2008 05:25:37 +0000

Read xUnit Test Patterns, there are a lot of test patterns that have DRY underpinnings.

By: Ben

Ben — Wed, 09 Jul 2008 04:32:05 +0000

@Greg - I tried, man, I tried. I worked hard to make my tests DRY for months, and trust me, it just created more problems than it solved.

Readability was one problem, but more importantly, making tests DRY makes them lest independent, which is a maintainability nightmare.

I’d say that if you find yourself needing to DRY up your tests (to reduce duplication), then your tests aren’t specific enough. If each test is verifying one specific thing, you shouldn’t need to write a bunch of helper methods.

By: website design

website design — Tue, 08 Jul 2008 21:24:49 +0000

I have slowly become more and more a believer of unit testing. One thing I find myself doing is instead of writing little single scripts or going into the interpreter directly is writing little unit tests when I am exploring new code. I have done this a lot recently when working with Amazon’s simpleDB, write code to write an object to the DB, before hooking it into any of my application, I write a test and make sure everything is doing what I expect.

By: Jack

Jack — Tue, 08 Jul 2008 09:25:58 +0000

@Greg - whilst I partially agree, it is better to have moist tests than none at all. My tests start wet, then I get them moist and finally I try to get them dry. The point being that the test code only exists to find bugs in the production code. if wet code does that initially then I don’t see a problem with it. You can always refactor to your hearts content later.

By: Greg

Greg — Tue, 08 Jul 2008 06:08:37 +0000

Tests should be DRY. If DRYing them up makes them less readable, you’re doing it wrong.