add pyee group util

tests/utils_test.py

@@ -0,0 +1,122 @@
+# Copyright 2021-2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+import contextlib
+from pyee import EventEmitter
+
+from bumble.utils import event_emitter_once_for_group, event_emitters_once_for_group
+
+
+# -----------------------------------------------------------------------------
+def test_event_emitter_once_for_group():
+    results = {'event1': None, 'event2': None, 'released': 0}
+
+    def handler1(x):
+        results['event1'] = x
+
+    def handler2(y):
+        results['event2'] = y
+
+    emitter = EventEmitter()
+
+    event_emitter_once_for_group(
+        emitter,
+        {
+            'event1': handler1,
+            'event2': handler2,
+        },
+    )
+
+    emitter.emit('event1', 'hello')
+
+    assert results['event1'] == 'hello'
+    assert results['event2'] is None
+
+    results['event1'] = None
+
+    emitter.emit('event1', 'hello')
+    emitter.emit('event2', 1234)
+
+    assert results['event1'] is None
+    assert results['event2'] is None
+
+    @contextlib.contextmanager
+    def managed():
+        try:
+            yield 1234
+        finally:
+            results['released'] += 1
+
+    event_emitter_once_for_group(
+        emitter,
+        {
+            'event1': handler1,
+            'event2': handler2,
+        },
+        managed(),
+    )
+
+    assert results['released'] == 0
+
+    emitter.emit('event2', 7756)
+
+    assert results['event1'] is None
+    assert results['event2'] == 7756
+    assert results['released'] == 1
+
+
+# -----------------------------------------------------------------------------
+def test_event_emitters_once_for_group():
+    results = {'event1': None, 'event2': None, 'released': 0}
+
+    def handler1(x):
+        results['event1'] = x
+
+    def handler2(y):
+        results['event2'] = y
+
+    emitter1 = EventEmitter()
+    emitter2 = EventEmitter()
+
+    event_emitters_once_for_group(
+        {
+            (emitter1, 'event1'): handler1,
+            (emitter2, 'event2'): handler2,
+        },
+    )
+
+    emitter1.emit('event1', 'hello')
+    emitter2.emit('event1', 'foobar')
+
+    assert results['event1'] == 'hello'
+    assert results['event2'] is None
+
+    results['event1'] = None
+
+    emitter1.emit('event1', 'hello')
+    emitter1.emit('event2', 1234)
+    emitter2.emit('event1', 'hello')
+    emitter2.emit('event2', 1234)
+
+    assert results['event1'] is None
+    assert results['event2'] is None
+
+
+# -----------------------------------------------------------------------------
+if __name__ == '__main__':
+    test_event_emitter_once_for_group()
+    test_event_emitters_once_for_group()