Wednesday, April 13, 2016

Testing the test tool

Going back to working on my HTTP contract testing tool, I've basically realized for the most part that I'm done!! Well, the minimal viable version is done. No bells and whistles just yet. So, why the lack of confidence in releasing it?

I've nothing in the region of acceptance tests. Over the last couple of years I've gotten exceedingly comfortable with this safety net to catch my numerous fuck-ups. My project is unit tested to an inch of its life. I'm comfortable that my coverage of 95% is exactly that, and worthwhile at the same time (maybe i'll add some mutation testing at some stage to see how accurate that 95% actually is).

In order to give myself that safety net and feel comfortable releasing my project I went about testing a test tool. Something I've never done before. A bit of background. Contract is a JVM testing tool designed to replace mocks and test clients in HTTP client server tests and provide identical yet separate test suites for both.

If I were testing a web-app, the first port of call would be to try to think like a user and use the system. Why not the same for a test library. I gave myself 2 users. A client and a server. I designed the simplest server I could think of, a server side map, send a key value pair it saves it for later retrieval. Paired with a client to provide java based access to the same server. I wrote the contracts to define expected behaviours. To follow my own best practices, I put the contracts in a third location so they were accessible to both.

The results: things didn't work exactly as i'd expected. My confident lack of confidence paid off again. Time to fix me some bugs!!!!

What went wrong exactly: when I left out the 'Content-Type' header the server responded with a 415. In the contract that defines this behaviour I left the body blank, I wasn't really concerned with what the body sent back, its usually garbage anyway. NullPointerException, bodies in the response of a contract are mandatory apparently.

Some links:

No comments: