Fix failing tests

Author: apottere

src/main/java/graphql/servlet/GraphQLServlet.java

@@ -178,7 +178,7 @@ public GraphQLServlet(ObjectMapperConfigurer objectMapperConfigurer, List<GraphQ
         };
     }
 
-    private ObjectMapper getMapper() {
+    protected ObjectMapper getMapper() {
         return lazyObjectMapperBuilder.getMapper();
     }
 
@@ -343,15 +343,9 @@ private <T> void runCallbacks(List<T> callbacks, Consumer<T> action) {
 
     protected static class VariablesDeserializer extends JsonDeserializer<Map<String, Object>> {
 
-        private final ObjectMapper mapper;
-
-        public VariablesDeserializer(@JacksonInject ObjectMapper mapper) {
-            this.mapper = mapper;
-        }
-
         @Override
         public Map<String, Object> deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
-            return deserializeVariablesObject(p.readValueAs(Object.class), mapper);
+            return deserializeVariablesObject(p.readValueAs(Object.class), (ObjectMapper) ctxt.findInjectableValue(ObjectMapper.class.getName(), null, null));
         }
     }
 

src/test/groovy/graphql/servlet/GraphQLServletSpec.groovy

@@ -407,6 +407,6 @@ class GraphQLServletSpec extends Specification {
 
     def "typeInfo is serialized correctly"() {
         expect:
-            GraphQLServlet.mapper.writeValueAsString(ExecutionTypeInfo.newTypeInfo().type(new GraphQLNonNull(Scalars.GraphQLString)).build()) != "{}"
+            servlet.getMapper().writeValueAsString(ExecutionTypeInfo.newTypeInfo().type(new GraphQLNonNull(Scalars.GraphQLString)).build()) != "{}"
     }
 }