Increase coverage

Author: oliemansm

graphql-webclient/src/main/java/graphql/kickstart/spring/webclient/boot/GraphQLResponse.java

@@ -41,7 +41,7 @@ private JsonNode readTree(String rawResponse) {
   }
 
   private List<GraphQLError> readErrors(JsonNode tree) {
-    if (tree.has(ERRORS_FIELD) && tree.get(ERRORS_FIELD) != null) {
+    if (tree.hasNonNull(ERRORS_FIELD)) {
       return convertList(tree.get(ERRORS_FIELD), GraphQLError.class);
     }
     return emptyList();
@@ -56,7 +56,7 @@ private JavaType constructListType(Class<?> type) {
   }
 
   public <T> T get(String fieldName, Class<T> type) {
-    if (data != null && data.has(fieldName) && data.get(fieldName) != null) {
+    if (data != null && data.hasNonNull(fieldName)) {
       return objectMapper.convertValue(data.get(fieldName), type);
     }
     return null;
@@ -74,7 +74,7 @@ private Optional<JsonNode> getFirstDataEntry() {
   }
 
   public <T> List<T> getList(String fieldName, Class<T> type) {
-    if (data != null && data.has(fieldName) && data.get(fieldName) != null) {
+    if (data != null && data.hasNonNull(fieldName)) {
       return convertList(data.get(fieldName), type);
     }
     return emptyList();

graphql-webclient/src/test/java/graphql/kickstart/spring/webclient/boot/GraphQLResponseTest.java

@@ -30,6 +30,12 @@ private GraphQLResponse constructResponse(String json) {
     return new GraphQLResponse(json, mockedMapper);
   }
 
+  @Test
+  void getErrors_noErrors_returnsEmptyList() {
+    GraphQLResponse response = constructResponse("{ \"data\": null }");
+    assertTrue(response.getErrors().isEmpty());
+  }
+
   @Test
   void getFieldName_dataIsNull_returnsNull() {
     GraphQLResponse response = constructResponse("{ \"data\": null }");