[FEATURE]Improve test coverage for RemoteModel.java

Added new tests for missing coverage. Mainly coverage was missing for catching exceptions in the methods initModel() and asyncPredict().
Also renamed some tests to match with testing methods.

Resolves opensearch-project#1382

Signed-off-by: Abdul Muneer Kolarkunnu <[email protected]>

ml-algorithms/src/test/java/org/opensearch/ml/engine/algorithms/remote/RemoteModelTest.java

@@ -15,6 +15,7 @@
 
 import java.util.Arrays;
 import java.util.Map;
+import java.util.Collections;
 
 import org.junit.Assert;
 import org.junit.Before;
@@ -31,6 +32,7 @@
 import org.opensearch.ml.common.connector.ConnectorAction;
 import org.opensearch.ml.common.connector.ConnectorProtocols;
 import org.opensearch.ml.common.connector.HttpConnector;
+import org.opensearch.ml.common.dataset.remote.RemoteInferenceInputDataSet;
 import org.opensearch.ml.common.exception.MLException;
 import org.opensearch.ml.common.input.MLInput;
 import org.opensearch.ml.common.transport.MLTaskResponse;
@@ -94,6 +96,17 @@ public void asyncPredict_NullConnectorExecutor() {
 
     @Test
     public void asyncPredict_ModelDeployed_WrongInput() {
+        asyncPredict_ModelDeployed_WrongInput("pre_process_function not defined in connector");
+    }
+
+    @Test
+    public void asyncPredict_With_RemoteInferenceInputDataSet() {
+        when(mlInput.getInputDataset()).thenReturn(
+                new RemoteInferenceInputDataSet(Collections.emptyMap(), ConnectorAction.ActionType.BATCH_PREDICT));
+        asyncPredict_ModelDeployed_WrongInput("no BATCH_PREDICT action found");
+    }
+
+    private void asyncPredict_ModelDeployed_WrongInput(String expExceptionMessage) {
         Connector connector = createConnector(ImmutableMap.of("Authorization", "Bearer ${credential.key}"));
         when(mlModel.getConnector()).thenReturn(connector);
         remoteModel.initModel(mlModel, ImmutableMap.of(), encryptor);
@@ -102,7 +115,7 @@ public void asyncPredict_ModelDeployed_WrongInput() {
         ArgumentCaptor<Exception> argumentCaptor = ArgumentCaptor.forClass(Exception.class);
         verify(actionListener).onFailure(argumentCaptor.capture());
         assert argumentCaptor.getValue() instanceof RuntimeException;
-        assertEquals("pre_process_function not defined in connector", argumentCaptor.getValue().getMessage());
+        assertEquals(expExceptionMessage, argumentCaptor.getValue().getMessage());
     }
 
     @Test