Execute step definitions as if they were pytest fixture.

This way we can get the same behaviour of yield-fixtures.

pytest_bdd/scenario.py

@@ -16,7 +16,7 @@ import re
 import typing
 
 import pytest
-from _pytest.fixtures import FixtureLookupError
+from _pytest.fixtures import FixtureLookupError, call_fixture_func
 
 from . import exceptions
 from .feature import get_feature, get_features
@@ -112,8 +112,9 @@ def _execute_step_function(request, scenario, step, step_func):
 
         request.config.hook.pytest_bdd_before_step_call(**kw)
         target_fixture = getattr(step_func, "target_fixture", None)
-        # Execute the step.
-        return_value = step_func(**kwargs)
+
+        # Execute the step as if it was a pytest fixture, so that we can allow "yield" statements in it
+        return_value = call_fixture_func(fixturefunc=step_func, request=request, kwargs=kwargs)
         if target_fixture:
             inject_fixture(request, target_fixture, return_value)
 

tests/feature/test_steps.py

@@ -484,3 +484,51 @@ def test_step_trace(testdir):
     result.assert_outcomes(failed=1)
     result.stdout.fnmatch_lines(["*test_when_step_validation_error*FAILED"])
     assert "INTERNALERROR" not in result.stdout.str()
+
+
+def test_steps_with_yield(testdir):
+    """Test that steps definition containing a yield statement work the same way as
+    pytest fixture do, that is the code after the yield is executed during teardown."""
+
+    testdir.makefile(
+        ".feature",
+        a="""\
+Feature: A feature
+
+    Scenario: A scenario
+        When I setup stuff
+        Then stuff should be 42
+""",
+    )
+    testdir.makepyfile(
+        textwrap.dedent(
+            """\
+        import pytest
+        from pytest_bdd import given, when, then, scenarios
+
+        scenarios("a.feature")
+
+        @when("I setup stuff", target_fixture="stuff")
+        def stuff():
+            print("Setting up...")
+            yield 42
+            print("Tearing down...")
+
+
+        @then("stuff should be 42")
+        def check_stuff(stuff):
+            assert stuff == 42
+            print("Asserted stuff is 42")
+
+        """
+        )
+    )
+    result = testdir.runpytest("-s")
+    result.assert_outcomes(passed=1)
+    result.stdout.fnmatch_lines(
+        [
+            "*Setting up...*",
+            "*Asserted stuff is 42*",
+            "*Tearing down...*",
+        ]
+    )