I’ve not used Unit Tests before other than a quick introduction in a Uni course. I’m currently writing an application though and would like to teach myself TDD in the process. The problem is, I’ve no idea what to test or really how.
I’m writing a Django application, and so far have only created the models (and customised the admin application). This is how I’ve written the skeletons of my tests so far:
class ModelTests(TestCase): fixtures = ['initial_data.json',] def setUp(self): pass def testSSA(self): ssa = SSA.objects.create(name='sdfsdf', cost_center=1111, street_num=8, street_name='dfsdfsf Street', suburb='sdfsdfsdf', post_code=3333) def testResident(self): pass def testSSA_Client(self): pass I planned to write a function to test each model within the ModelTests class. Is this a good way of writing tests? Also, what exactly should I be testing for? That creating a model with all of the fields completed works? That a half complete model fails? That any special cases are tested (like a null and is_required=False)? I’ve trust in the ORM, which as far as I’m aware is heavily tested, so I shouldn’t need to test all of the methods should I?
What do I need to test for a web application written in Django/Python? Some examples would be nice.
Is a function to test each model within the ModelTests class a good way of writing tests?
No.
What exactly should I be testing for?
That creating a model with all of the fields completed works?
That a half complete model fails?
That any special cases are tested (like a null and is_required=False)?
I’ve trust in the ORM, which as far as I’m aware is heavily tested, so I shouldn’t need to test all of the methods should I?
Not much of that.
You might test validation rules, but that isn’t meaningful until you’ve defined some Form objects. Then you have something to test — does the form enforce all the rules. You’ll need at least one TestCase class for each form. A function will be a scenario — different combinations of inputs that are allowed or not allowed.
For each Model class, you’ll need at least one TestCase class definition. TestCases are cheap, define lots of them.
Your model embodies your ‘business entity’ definitions. Your models will have methods that implement business rules. Your methods will do things like summarize, filter, calculate, aggregate, reduce, all kinds of things. You’ll have functions for each of these features of a model class.
You’re not testing Django. You’re testing how your business rules actually work in Django.
Later, when you have more stuff in your application (forms, views, urls, etc.) you’ll want to use the Django unittest client to exercise each method for each url. Again, one TestCase per