Ensure setRequest cannot be passed null

Signed-off-by: Craig Perkins <[email protected]>

modules/lang-mustache/src/main/java/org/opensearch/script/mustache/SearchTemplateRequest.java

@@ -89,6 +89,7 @@ public SearchTemplateRequest(SearchRequest searchRequest) {
     }
 
     public void setRequest(SearchRequest request) {
+        Objects.requireNonNull(request);
         this.request = request;
     }
 

modules/lang-mustache/src/test/java/org/opensearch/script/mustache/SearchTemplateRequestTests.java

@@ -38,6 +38,7 @@
 import org.opensearch.search.RandomSearchRequestGenerator;
 import org.opensearch.search.builder.SearchSourceBuilder;
 import org.opensearch.test.AbstractWireSerializingTestCase;
+import org.junit.Assert;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -113,8 +114,7 @@ public static SearchTemplateRequest createRandomRequest() {
     }
 
     public void testSimulatedSearchTemplateRequest() {
-        SearchTemplateRequest request = createRandomRequest();
-        request.setRequest(null);
+        SearchTemplateRequest request = new SearchTemplateRequest();
         request.setSimulate(true);
 
         assertEquals(0, request.indices().length);
@@ -127,4 +127,9 @@ public void testSimulatedSearchTemplateRequest() {
 
         assertEquals(expectedIndicesLength, randomRequest.indices().length);
     }
+
+    public void testSearchTemplateRequestSetRequestCannotBeNull() {
+        SearchTemplateRequest request = new SearchTemplateRequest();
+        Assert.assertThrows(NullPointerException.class, () -> request.setRequest(null));
+    }
 }