Can tests with pytest fixtures be run interactively?

Question

I have some tests written using pytest and fixtures, e.g.:

class TestThing:
    @pytest.fixture()
    def temp_dir(self, request):
        my_temp_dir = tempfile.mkdtemp()
        def fin():
            shutil.rmtree(my_temp_dir)
        request.addfinalizer(fin)
        return my_temp_dir
    def test_something(self, temp_dir)
        with open(os.path.join(temp_dir, 'test.txt'), 'w') as f:
            f.write('test')

This works fine when the tests are invoked from the shell, e.g.

 $ py.test

but I don't know how to run them from within a python/ipython session; trying e.g.

tt = TestThing()
tt.test_something(tt.temp_dir())

fails because temp_dir requires a request object to be passed on. So, how does one invoke a fixture with a request object injected?

Answer 1

Yes. You don't have to manually assemble any test fixtures or anything like that. Everything runs just like calling pytest in the project directory.

Method1:

This is the best method because it gives you access to the debugger if your test fails

In ipython shell use:

**ipython**> run -m pytest prj/

This will run all your tests in the prj/tests directory.

This will give you access to the debugger, or allow you to set breakpoints if you have a import ipdb; ipdb.set_trace() in your program (https://docs.pytest.org/en/latest/usage.html#setting-breakpoints).

Method2:

Use !pytest while in the test directory. This wont give you access to the debugger. However, if you use

**ipython**> !pytest --pdb

If you have a test failure, it will drop you into the debugger (subshell), so you can run your post-mortem analysis (https://docs.pytest.org/en/latest/usage.html#dropping-to-pdb-python-debugger-on-failures)

---

Using these methods you can even run individual modules/test_fuctions/TestClasses in ipython using (https://docs.pytest.org/en/latest/usage.html#specifying-tests-selecting-tests)

**ipython**> run -m pytest prj/tests/test_module1.py::TestClass1::test_function1

Answer 2

You can bypass the pytest.fixture decorator and directly call the wrapped test function.

tmp = tt.temp_dir.__pytest_wrapped__.obj(request=...)

Accessing internals, it's bad, but when you need it...