test(pyamber): add unit tests for port_storage_writer

amber/src/test/python/core/storage/runnables/test_port_storage_writer.py

@@ -0,0 +1,74 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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
+#
+#   http://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.
+
+from unittest.mock import MagicMock
+
+import pytest
+
+from core.util.customized_queue.queue_base import QueueControl, QueueElement
+from core.storage.runnables.port_storage_writer import (
+    PortStorageWriter,
+    PortStorageWriterElement,
+)
+
+
+@pytest.fixture
+def writer_mock():
+    return MagicMock()
+
+
+@pytest.fixture
+def writer(writer_mock):
+    return PortStorageWriter(buffered_item_writer=writer_mock, queue=MagicMock())
+
+
+class TestReceive:
+    def test_dispatches_data_tuple_to_buffered_item_writer(self, writer, writer_mock):
+        data_tuple = object()
+        element = PortStorageWriterElement(data_tuple=data_tuple)
+
+        writer.receive(element)
+
+        # The wrapped tuple is forwarded verbatim to the underlying writer.
+        writer_mock.put_one.assert_called_once_with(data_tuple)
+
+    def test_raises_type_error_on_a_plain_queue_element(self, writer, writer_mock):
+        with pytest.raises(TypeError):
+            writer.receive(QueueElement())
+
+        # A non-data element must never be written out.
+        writer_mock.put_one.assert_not_called()
+
+    def test_raises_type_error_on_a_control_message(self, writer, writer_mock):
+        with pytest.raises(TypeError):
+            writer.receive(QueueControl(msg="stop"))
+
+        writer_mock.put_one.assert_not_called()
+
+
+class TestLifecycle:
+    def test_pre_start_opens_the_writer(self, writer, writer_mock):
+        writer.pre_start()
+
+        writer_mock.open.assert_called_once_with()
+        writer_mock.close.assert_not_called()
+
+    def test_post_stop_closes_the_writer(self, writer, writer_mock):
+        writer.post_stop()
+
+        writer_mock.close.assert_called_once_with()
+        writer_mock.open.assert_not_called()