PHPUnit - test MVC controller with $_POST variable

Question

I'm starting work with PHPUnit with Kohana. My application have many controllers which simply takes data from some form, validates and inserts/updates/deletes into/-/from database. How should I write a test cases for that.

I know that if I want to test a function I write data provider function and just compare returned value with the expected one. But my input data (data from forms) is being passed in $_POST variable. How should I test this? And after that, should I check if inserted data is really in database? Please give my some guidlines for that type of tests or links to some examples/tutorials. Thanks.

Answer 1

First of all, if you are testing all the way from receiving the POSTed data to checking values in the database, this is not unit-test anymore : you are not testing one component in isolation of the others, but you are testing the integration of those components together.

It makes things harder to test :

• you have to provide data in harder ways : not just as parameters to a method, but as parameters to your whole application (which means forging POST data, here, for instance)
• you have more things to verify : not just the return value of a method, or if it threw an exception
• you have several different and maybe unrelated things that can cause a failure (problem in some PHP code, problem in the database, database server not being available, ...), which will make failures harder to track down to find their cause.

Note that I didn't say that kind of "integration" tests is not useful, btw ;-)

Still, forging the $_POST array is quite simple : it is not read-only, and you can store whatever you want in it.

So, at the begining of your test-case, nothing prevents you from injecting any data you need in it.