Remove the unnecessary DeltaExtras constructor on MessageExtras.

lib/src/main/java/io/ably/lib/types/MessageExtras.java

@@ -36,13 +36,6 @@ public MessageExtras(final JsonObject jsonObject) {
 		this(jsonObject, null);
 	}
 
-	/**
-	 * @since 1.2.0
-	 */
-	public MessageExtras(final DeltaExtras delta) {
-		this(Serializer.wrapDelta(delta), delta);
-	}
-
 	private MessageExtras(final JsonObject jsonObject, final DeltaExtras delta) {
 		if (null == jsonObject) {
 			throw new NullPointerException("jsonObject cannot be null.");

lib/src/test/java/io/ably/lib/test/realtime/RealtimeDeltaDecoderTest.java

@@ -5,6 +5,7 @@
 
 import java.util.Objects;
 
+import com.google.gson.JsonObject;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.Timeout;
@@ -133,19 +134,27 @@ public ITransport getTransport(ITransport.TransportParams transportParams, Conne
 	 * Special transport class that corrupts the order bookkeeping of delta messages to allow testing delta recovery.
 	 */
 	private static class OutOfOrderDeltasWebsocketTransportMock extends WebSocketTransport {
-
+		private static final String DELTA = "delta";
 
 		private OutOfOrderDeltasWebsocketTransportMock(TransportParams transportParams, ConnectionManager connectionManager) {
 			super(transportParams, connectionManager);
 		}
 
 		@Override
-		protected void preProcessReceivedMessage(ProtocolMessage message) {
-			if(message.action == ProtocolMessage.Action.message &&
-				message.messages[0].extras != null &&
-				message.messages[0].extras.getDelta() != null) {
-					final String format = message.messages[0].extras.getDelta().getFormat();
-					message.messages[0].extras = new MessageExtras(new DeltaExtras(format, ""));
+		protected void preProcessReceivedMessage(ProtocolMessage protocolMessage) {
+			if(protocolMessage.action == ProtocolMessage.Action.message) {
+				for (final Message message : protocolMessage.messages) {
+					final MessageExtras extras = message.extras;
+					if (extras != null) {
+						final JsonObject json = message.extras.asJsonObject();
+
+						if (json.has(DELTA)) {
+							// This MessageExtras (json) has DeltaExtras.
+							// Corrupt it by replacing the value at the from key with an empty string.
+							json.getAsJsonObject(DELTA).addProperty("from", "");
+						}
+					}
+				}
 			}
 		}
 	}

lib/src/test/java/io/ably/lib/types/MessageExtrasTest.java

@@ -62,68 +62,4 @@ public void rawViaMessagePack() throws IOException {
 	public void rawNullArgument() {
 		new MessageExtras((JsonObject)null);
 	}
-
-	/**
-	 * Construct an instance with DeltaExtras and validate that the
-	 * serialised JSON is as expected. Also validate that the DeltaExtras
-	 * retrieved is the same.
-	 */
-	@Test
-	public void delta() {
-		final DeltaExtras deltaExtrasA = new DeltaExtras("someFormat", "someSource");
-		final DeltaExtras deltaExtrasB = new DeltaExtras("someFormat", "someOtherSource");
-
-		final MessageExtras messageExtras = new MessageExtras(deltaExtrasA);
-		assertEquals(deltaExtrasA, messageExtras.getDelta());
-		assertNotEquals(deltaExtrasB, messageExtras.getDelta());
-		assertNotEquals(deltaExtrasB, deltaExtrasA);
-
-		final JsonObject expectedJsonElement = deltaExtrasJsonObject("someFormat", "someSource");
-
-		final MessageExtras.Serializer serializer = new MessageExtras.Serializer();
-		final JsonElement serialised = serializer.serialize(messageExtras, null, null);
-
-		assertEquals(expectedJsonElement, serialised);
-	}
-
-	/**
-	 * Construct an instance with DeltaExtras and validate that it can be encoded
-	 * to MessagePack and then decoded back again from MessagePack.
-	 */
-	@Test
-	public void deltaViaMessagePack() throws IOException {
-		final DeltaExtras deltaExtras = new DeltaExtras("tamrof", "morf");
-		final MessageExtras messageExtras = new MessageExtras(deltaExtras);
-		final JsonObject expectedMessageExtrasJsonObject = deltaExtrasJsonObject("tamrof", "morf");
-		assertEquals(expectedMessageExtrasJsonObject, messageExtras.asJsonObject());
-
-		// Encode to MessagePack
-		final ByteArrayOutputStream out = new ByteArrayOutputStream();
-		final MessagePacker packer = Serialisation.msgpackPackerConfig.newPacker(out);
-		messageExtras.write(packer);
-		packer.flush();
-
-		// Decode from MessagePack
-		System.out.println("len: " + out.toByteArray().length);
-		MessageUnpacker unpacker = Serialisation.msgpackUnpackerConfig.newUnpacker(out.toByteArray());
-		final MessageExtras unpacked = MessageExtras.read(unpacker);
-
-		assertEquals(messageExtras.getDelta(), unpacked.getDelta());
-		assertEquals(messageExtras, unpacked);
-		assertEquals(expectedMessageExtrasJsonObject, unpacked.asJsonObject());
-	}
-
-	@Test(expected = NullPointerException.class)
-	public void deltaNullArgument() {
-		new MessageExtras((DeltaExtras)null);
-	}
-
-	private static JsonObject deltaExtrasJsonObject(final String format, final String from) {
-		final JsonObject deltaExtrasJsonElement = new JsonObject();
-		deltaExtrasJsonElement.addProperty("format", format);
-		deltaExtrasJsonElement.addProperty("from", from);
-		final JsonObject jsonElement = new JsonObject();
-		jsonElement.add("delta", deltaExtrasJsonElement);
-		return jsonElement;
-	}
 }