Merge pull request #3802 from Zac-HD/testcase-subclass-settings

Author: Zac-HD

hypothesis-python/RELEASE.rst

@@ -0,0 +1,18 @@
+RELEASE_TYPE: patch
+
+This patch supports assigning ``settings = settings(...)`` as a class attribute
+on a subclass of a ``.TestCase`` attribute of a :class:`~hypothesis.stateful.RuleBasedStateMachine`.
+Previously, this did nothing at all.
+
+.. code-block: python
+
+    # works as of this release
+    class TestMyStatefulMachine(MyStatefulMachine.TestCase):
+        settings = settings(max_examples=10000)
+
+    # the old way still works, but it's more verbose.
+    MyStateMachine.TestCase.settings = settings(max_examples=10000)
+    class TestMyStatefulMachine(MyStatefulMachine.TestCase):
+        pass
+
+Thanks to Joey Tran for reporting these settings-related edge cases in stateful testing.

hypothesis-python/src/hypothesis/stateful.py

@@ -402,7 +402,7 @@ class StateMachineTestCase(TestCase):
             settings = Settings(deadline=None, suppress_health_check=list(HealthCheck))
 
             def runTest(self):
-                run_state_machine_as_test(cls)
+                run_state_machine_as_test(cls, settings=self.settings)
 
             runTest.is_hypothesis_test = True
 

hypothesis-python/tests/nocover/test_stateful.py

@@ -186,3 +186,18 @@ def test_bad_machines_fail(machine):
         notes = err.__notes__
     steps = [l for l in notes if "Step " in l or "state." in l]
     assert 1 <= len(steps) <= 50
+
+
+class MyStatefulMachine(RuleBasedStateMachine):
+    def __init__(self):
+        self.n_steps = 0
+        super().__init__()
+
+    @rule()
+    def step(self):
+        self.n_steps += 1
+        assert self.n_steps <= 10
+
+
+class TestMyStatefulMachine(MyStatefulMachine.TestCase):
+    settings = Settings(derandomize=True, stateful_step_count=5)