json-merge-patch, add cadl ranch test (#2550)

* json-merge-patch, add cadl ranch test

* refine code

* refactor

* Update JsonMergePatchClientTest.java

typespec-tests/src/test/java/com/payload/jsonmergepatch/JsonMergePatchClientTest.java

@@ -0,0 +1,69 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.payload.jsonmergepatch;
+
+
+import com.payload.jsonmergepatch.models.InnerModel;
+import com.payload.jsonmergepatch.models.Resource;
+import com.payload.jsonmergepatch.models.ResourcePatch;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class JsonMergePatchClientTest {
+
+    private final JsonMergePatchClient client = new JsonMergePatchClientBuilder().buildClient();
+
+    @Test
+    public void createAndUpdateResource() {
+        // create resource
+        Resource resource = buildResource();
+        client.createResource(resource);
+        // update resource
+        ResourcePatch resourcePatch = buildResourcePatchWithNullProperties();
+        client.updateResource(resourcePatch);
+    }
+
+    @Test
+    public void updateOptionalResource() {
+        ResourcePatch resourcePatch = buildResourcePatchWithNullProperties();
+        client.updateOptionalResource(resourcePatch);
+    }
+
+    private static Resource buildResource() {
+        InnerModel innerModel = new InnerModel();
+        innerModel.setName("InnerMadge");
+        innerModel.setDescription("innerDesc");
+        Map<String, InnerModel> map = new HashMap<>();
+        map.put("key", innerModel);
+        List<InnerModel> array = Arrays.asList(innerModel);
+        Resource resource = new Resource("Madge");
+        resource.setArray(array);
+        resource.setMap(map);
+        resource.setDescription("desc");
+        resource.setIntValue(1);
+        resource.setFloatValue(1.1);
+        resource.setInnerModel(innerModel);
+        resource.setIntArray(Arrays.asList(1, 2, 3));
+        return resource;
+    }
+
+    private static ResourcePatch buildResourcePatchWithNullProperties() {
+        ResourcePatch resourcePatch = new ResourcePatch();
+        resourcePatch.setDescription(null);
+        resourcePatch.setMap(new HashMap<>());
+        resourcePatch.getMap().put("key", new InnerModel().setDescription(null));
+        resourcePatch.getMap().put("key2", null);
+        resourcePatch.setArray(null);
+        resourcePatch.setInnerModel(null);
+        resourcePatch.setIntValue(null);
+        resourcePatch.setFloatValue(null);
+        resourcePatch.setInnerModel(null);
+        resourcePatch.setIntArray(null);
+        return resourcePatch;
+    }
+}