pytest class with different parameters

[SebastianZa]

Hi all,

I have a question regarding using pytest with test classes. I wrote such a testclass which basically looks as follows:

class Test_HW:

def setup_class(cls):
    init_if (chosen_if)

def test_nr1():
     # do anything

def test_nr2():
     # do anything

def teardown_class(cls):
  deinit_if(chosen_if)

Everything works as intended. But now I want to do the following: chosen_if shall not be hardcoded but the whole class shall run with two if both connected to my DUT:

• chosen_if = "SPI"
• chosen_if = "I2C"

Is this possibly anyhow? I'm quite new in pytest and I googled for hours but only found solutions which can be used for the test_xxx() functions itself but not for the whole class.

So far, chosen_if is hardcoded to "SPI". If I want to test the second_if (I2C) I have to change in the source code. Later on the test shall run on Jenkins so this is not a solution at all. :)

Is there a good way to do what I want?

Kind regards!
Sebastian

[The-Compiler]

The setup_class and teardown_class methods you describe are actually from pytest's support of unittest/nose, and not the "native" way of doing this with pytest.

A more pytest-like and powerful mechanism to achieve the same goal are pytest's fixtures - they'll take a bit of time to wrap your head around, but are totally worth it!

Your code could perhaps look like this (with a couple of assumption, your original code has various issues):

class Test_HW:

    @pytest.fixture(autouse=True)
    def interface(self):
        # before every test
        init_if(chosen_if)
        yield
        # after every test
        deinit_if(chosen_if)

    def test_nr1(self):
        # do anything

    def test_nr2(self):
        # do anything

such a fixture can then be parametrized:

class Test_HW:

    @pytest.fixture(autouse=True, params=['i2c', 'spi'])
    def interface(self, request):
        # before every test
        init_if(request.param)  # 'i2c' or 'spi'
        yield
        # after every test
        deinit_if(request.param)

    def test_nr1(self):
        # do anything

    def test_nr2(self):
        # do anything

[SebastianZa]

Hi Florian ( @The-Compiler ),

thanks for the great help. I tried with my initial test class and it worked out of the box. I will now proceed with defining the testcases. :)

Kind regards
Sebastian