Pytest: When to use with pytest.raises vs xfail

I have a method which is expected to raise an exception when an incorrect format of input is provided. I am wondering which is the correct way to test, when an incorrect input is supplied mark the test as xfail or actually test it with pytest.raises to see the actual exception is raised.

You can use xfail , if you expect the function to raise an exception.

But there may be cases of exceptions other than incorrect format, where you want to consider them as failure.

Then you can use "raises" parameter as shown below in xfail

@pytest.mark.xfail(raises=YourFormatExceptionType)

After this any other exception other than the one specified in raises, will be considered as a regular failure.

You can pass a single exception or a tuple of exceptions to raises in the above function.

Related documentation:

https://docs.pytest.org/en/latest/how-to/skipping.html#raises-parameter