bt2: wrap bt_graph_run_once() (Graph.run_once())

[babeltrace.git] / tests / bindings / python / bt2 / test_graph.py

diff --git a/tests/bindings/python/bt2/test_graph.py b/tests/bindings/python/bt2/test_graph.py
index b7c0f0cb22f19cf6f82ce7a7d424b1f48adf2127..49c08512505c8210e2446ff338ee91cbb91edeb6 100644 (file)
--- a/tests/bindings/python/bt2/test_graph.py
+++ b/tests/bindings/python/bt2/test_graph.py
@@ -349,6 +349,59 @@ class GraphTestCase(unittest.TestCase):
         )
         self._graph.run()
 
+    def test_run_once(self):
+        class MyIter(_MyIter):
+            pass
+
+        class MySource(bt2._UserSourceComponent, message_iterator_class=MyIter):
+            def __init__(self, params, obj):
+                self._add_output_port('out')
+
+        class MySink(bt2._UserSinkComponent):
+            def __init__(self, params, obj):
+                self._input_port = self._add_input_port('in')
+
+            def _user_consume(comp_self):
+                nonlocal run_count
+                run_count += 1
+                raise bt2.TryAgain
+
+        run_count = 0
+        src = self._graph.add_component(MySource, 'src')
+        sink = self._graph.add_component(MySink, 'sink')
+        conn = self._graph.connect_ports(
+            src.output_ports['out'], sink.input_ports['in']
+        )
+
+        with self.assertRaises(bt2.TryAgain):
+            self._graph.run_once()
+
+        self.assertEqual(run_count, 1)
+
+    def test_run_once_stops(self):
+        class MyIter(_MyIter):
+            pass
+
+        class MySource(bt2._UserSourceComponent, message_iterator_class=MyIter):
+            def __init__(self, params, obj):
+                self._add_output_port('out')
+
+        class MySink(bt2._UserSinkComponent):
+            def __init__(self, params, obj):
+                self._input_port = self._add_input_port('in')
+
+            def _user_consume(comp_self):
+                raise bt2.Stop
+
+        src = self._graph.add_component(MySource, 'src')
+        sink = self._graph.add_component(MySink, 'sink')
+        conn = self._graph.connect_ports(
+            src.output_ports['out'], sink.input_ports['in']
+        )
+
+        with self.assertRaises(bt2.Stop):
+            self._graph.run_once()
+
     def test_run_again(self):
         class MyIter(_MyIter):
             def __next__(self):