Mockstar -- Declarative Mocking Like a Rockstar!
Mockstar is a small enhance on top of Mock library that gives you declarative way to write your unit-tests.
Usually, unit under test is something simple, like function or method. It's result is dependent on it's arguments and calls to some external dependencies (side-effects). For example, here:
Unit under test is PostForm class (more precicely, it's clean method here), it has one side-effect, which is is_post_exist function.
Usually, you create a single test module for single code module (well, I do). So in this example module under test would be myapp.blog.forms.
Minimal test-case example
Your minimal test case would look something like this:
More detailed introduction
So, you want to implement and test your unit. Let's say it's a function :func:`create_user` that will look like this when it is done:
This unit consists of input-parameters:
and seven side-effects:
- User model
- not_md5_and_has_salt function
- count_score function
- choose_low_quality_avatar function
- choose_high_quality_avatar function
- mail business-logic
- discover_possible_friends function
So, to test this unit in isolation we would need to mock-out all side-effects, on every test put some return-values so that they will fit our if-else clauses, and finally, generate suitable input-parameters.
With Mock library, you would do something like this:
Problems I see:
- need to repeat mocked names as test parameters
- need to write autospec=True again and again
- need to write module prefix app.bl.user on every patch call
- need to patch on every test case
- need to add common return_values and assign to some variables (like user) that we'll use later in asserts
- side_effects take a lot of space in our testing code, I want to separate them
With mockstar your test would look something like this:
I hope you like mockstar's aspiration to get declarative way of writing unit-tests and reduce of copypasta.
To install mockstar, just type:
pip install mockstar