I'm using the Template Method Pattern for my test cases, i.e. they have the following structure:

Parent(unittest.TestCase)
  |
  |---- Child1
  |---- Child2
  |---- Child3

Test cases are defined in the parent. Each child implements a certain different setup.

When I run my tests with pytest (python -m pytest), I want the inherited tests in Child1 - Child3 to be run, but the ones defined in Parent should not run. They should also not yield a failing test.

How can I do that?

I'm using python_classes= in pytest.ini, so tests are not selected based on names. Changing that is not an option.

I tried:

• Making Parent abstract. Result: Parent fails to instantiate, tests are marked as failed.
• Setting __test__ = False in Parent. Result: Child tests are also not executed.

I'm using the Template Method Pattern for my test cases, i.e. they have the following structure:

Parent(unittest.TestCase)
  |
  |---- Child1
  |---- Child2
  |---- Child3

Test cases are defined in the parent. Each child implements a certain different setup.

When I run my tests with pytest (python -m pytest), I want the inherited tests in Child1 - Child3 to be run, but the ones defined in Parent should not run. They should also not yield a failing test.

How can I do that?

I'm using python_classes= in pytest.ini, so tests are not selected based on names. Changing that is not an option.

I tried:

• Making Parent abstract. Result: Parent fails to instantiate, tests are marked as failed.
• Setting __test__ = False in Parent. Result: Child tests are also not executed.

• python
• pytest

1 Answer 1

Use composite inheritance

Source: sqlpey

class Parent: # no inheritance

  # treat this class as a test class...

  # ... have a setUp method
  def setUp(self):
    ....

  # ... define your tests
  def test_1(self):
    ...

  def abstract_method(self):
     raise Exception("Implement in Child")


class Child1(Parent, unittest.TestCase):
   ...

Very important: first state your Parent, second TestCase. Otherwise it won't collect/run your tests as expected.

Other Suboptimal solutions

If it's ok to have the tests in the Parent class marked as "passed", you can use the following.

Option 1: Let the abstract method only fail if not implemented in child classes

class Parent(unittest.TestCase):
  def my_abstract_method(self):
    if(type(self) == Parent):
        return 
    else:
        raise Exception("Please implement in sub class.")

Option 2: Let the test not run in parent class

class Parent(unittest.TestCase):
  def test_1(self):
     if(type(self) == Parent): return 

     ...

Problem: all parent tests will also collected for each child. I.e. if you defined 4 tests in your parent, then run tests of your Child 8 tests will be run (4 tests of the child and 4 of the Parent)