Support for async steps

pyproject.toml

@@ -48,6 +48,7 @@ types-setuptools = "^65.5.0.2"
 pytest-xdist = "^3.0.2"
 coverage = {extras = ["toml"], version = "^6.5.0"}
 Pygments = "^2.13.0"  # for code-block highlighting
+pytest-asyncio = "^0.21.1"
 
 [build-system]
 requires = ["poetry-core>=1.0.0"]

src/pytest_bdd/scenario.py

@@ -12,7 +12,9 @@
 """
 from __future__ import annotations
 
+import asyncio
 import contextlib
+import functools
 import logging
 import os
 import re
@@ -120,6 +122,19 @@ def get_step_function(request, step: Step) -> StepFunctionContext | None:
             return None
 
 
+def ensure_sync(fn):
+    """Convert async function to sync function."""
+    __tracebackhide__ = True
+    if not asyncio.iscoroutinefunction(fn):
+        return fn
+
+    @functools.wraps(fn)
+    def wrapper(*args, **kwargs):
+        return asyncio.run(fn(*args, **kwargs))
+
+    return wrapper
+
+
 def _execute_step_function(
     request: FixtureRequest, scenario: Scenario, step: Step, context: StepFunctionContext
 ) -> None:
@@ -156,7 +171,8 @@ def _execute_step_function(
 
         request.config.hook.pytest_bdd_before_step_call(**kw)
         # 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=context.step_func, request=request, kwargs=kwargs)
+        step_func = ensure_sync(context.step_func)
+        return_value = call_fixture_func(fixturefunc=step_func, request=request, kwargs=kwargs)
     except Exception as exception:
         request.config.hook.pytest_bdd_step_error(exception=exception, **kw)
         raise

tests/library/test_async.py

@@ -0,0 +1,69 @@
+import textwrap
+
+
+# TODO: Split this test in one that checks that we work correctly
+# with the pytest-asyncio plugin, and another that checks that we correctly
+# run async steps.
+def test_async_steps(pytester):
+    """Test parent given is collected.
+
+    Both fixtures come from the parent conftest.
+    """
+    pytester.makefile(
+        ".feature",
+        async_feature=textwrap.dedent(
+            """\
+            Feature: A feature
+                Scenario: A scenario
+                    Given There is an async object
+
+                    When I do an async action
+
+                    Then the async object value should be "async_object"
+                    And [async] the async object value should be "async_object"
+                    And the another async object value should be "another_async_object"
+            """
+        ),
+    )
+
+    pytester.makepyfile(
+        textwrap.dedent(
+            """\
+        from pytest_bdd import given, parsers, scenarios, then, when
+        import asyncio
+        import pytest
+
+        scenarios("async_feature.feature")
+
+        @pytest.fixture
+        async def another_async_object():
+            await asyncio.sleep(0.01)
+            return "another_async_object"
+
+        @given("There is an async object", target_fixture="async_object")
+        async def given_async_obj():
+            await asyncio.sleep(0.01)
+            return "async_object"
+
+        @when("I do an async action")
+        async def when_i_do_async_action():
+            await asyncio.sleep(0.01)
+
+        @then(parsers.parse('the async object value should be "{value}"'))
+        async def the_sync_object_value_should_be(async_object, value):
+            assert async_object == value
+
+        @then(parsers.parse('[async] the async object value should be "{value}"'))
+        async def async_the_async_object_value_should_be(async_object, value):
+            await asyncio.sleep(0.01)
+            assert async_object == value
+
+        @then(parsers.parse('the another async object value should be "{value}"'))
+        def the_another_async_object_value_should_be(another_async_object, value):
+            assert another_async_object == value
+
+        """
+        )
+    )
+    result = pytester.runpytest("--asyncio-mode=auto")
+    result.assert_outcomes(passed=1)