Misleading error message when parameters are missing in the parametrize but presented in the test function

• a detailed description of the bug or problem you are having
• output of pip list from the virtual environment you are using
• pytest and operating system versions
• minimal example if possible

I’m using pytest version 6.2.4. Say we have the following function and a corresponding test function:

# ./add.py
def add(n1, n2):
  return n1 + n2

# ./test_add.py
@pytest.mark.parametrize(
  "arg1, expected_answer",
  [pytest.param(2, 3, 5)]
)
def test_add(arg1, arg2, expected_answer):
  assert add(arg1, arg2) == expected_answer

Running pytest ./test_add.py::test_add logs the following error message:

ERROR: not found: ./test_add.py::test_add
(no name './test_add.py::test_add' in any of [<Module test_add.py>])

But actually it fails because arg2 is not presented in the parametrize decorator. Similar issue when the argument name is wrong.

[jekwatt]

I was able to duplicate the error. Working to fix the error message.

[The-Compiler]

This is the full output:

============================= test session starts ==============================
collected 0 items / 1 error                                                    

==================================== ERRORS ====================================
_________________________ ERROR collecting test_add.py _________________________
test_add.py::test_add: in "parametrize" the number of names (2):
  ['arg1', 'expected_answer']
must be equal to the number of values (3):
  (2, 3, 5)
=========================== short test summary info ============================
ERROR test_add.py
=============================== 1 error in 0.04s ===============================
ERROR: not found: /home/florian/tmp/test_add.py::test_add
(no name '/home/florian/tmp/test_add.py::test_add' in any of [<Module test_add.py>])

seems quite clear from that what the error is, no?