Issue 29: Unit test from streamcut API (#28)

Add unit test for get_streamcut() API which gives all reader positions in stream segment for given readergroup

Signed-off-by: Shwetha N <[email protected]>

tests/pravega_reader_test.py

@@ -321,3 +321,52 @@ async def test_largeEvents(self):
                 count+=1
                 self.assertEqual(b'a'*100000, event.data(), "Invalid event data")
             r1.release_segment(segment_slice)
+
+    # Test to read the events and get streamCut
+    # Enable RG to read from given streamcut.
+    async def test_getStreamcut(self):
+        suffix = str(random.randint(0, 100))
+        scope = "testReaderSC"
+        stream = "testStream" + suffix
+        print("Creating a Stream Manager, ensure Pravega is running")
+        stream_manager = pravega_client.StreamManager("tcp://127.0.0.1:9090")
+        pravega_client.StreamReaderGroupConfig(True, scope, stream)
+        print("Creating a scope")
+        scope_result = stream_manager.create_scope(scope)
+        print(scope_result)
+        print("Creating a stream ", stream)
+        stream_result = stream_manager.create_stream(scope, stream, 1)
+        print(stream_result)
+        w1 = stream_manager.create_writer(scope, stream)
+
+        print("Write 2 events")
+        w1.write_event("event1")
+        w1.write_event("event2")
+        w1.flush()
+
+        # Create a reader Group points to tail of the stream.
+        reader_group = stream_manager.create_reader_group("rgnew" + suffix, scope, stream, True)
+
+        # get Streamcut which points to 3rd event
+        rsm = reader_group.get_streamcut()
+        print(rsm)
+        # write 3 more events
+        w1.write_event("event3")
+        w1.write_event("event4")
+        w1.write_event("event5")
+        w1.flush()
+        # Create ReaderGroup by passing streamcut which points to 3rd event.
+        reader_group2 = stream_manager.create_reader_group("rgnew" + suffix, scope, stream, False, rsm)
+        # consume the segment slice for events. Read all 3 events from given slice.
+        r1 = reader_group2.create_reader("reader-1")
+        segment_slice = await r1.get_segment_slice_async()
+        count = 0
+        event_num = 2
+        for event in segment_slice:
+            count += 1
+            event_num += 1
+            self.assertEqual(b'event' + str(event_num).encode(), event.data(), "Invalid event data")
+
+        self.assertEqual(count, 3, "Three events are expected")
+        r1.release_segment(segment_slice)
+        r1.reader_offline()