diff --git a/spring-graphql-test/build.gradle b/spring-graphql-test/build.gradle
index 8423b255..cf22ea3a 100644
--- a/spring-graphql-test/build.gradle
+++ b/spring-graphql-test/build.gradle
@@ -2,6 +2,7 @@
 plugins {
 	id 'io.spring.dependency-management' version '1.0.10.RELEASE'
 	id 'java-library'
+	id "org.springframework.graphql.conventions"
 }
 
 description = "Spring Support for Testing GraphQL Applications"
diff --git a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultGraphQlTester.java b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultGraphQlTester.java
index 49cdf37e..d1aef807 100644
--- a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultGraphQlTester.java
+++ b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultGraphQlTester.java
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.test.tester;
 
 import java.net.URI;
@@ -61,6 +62,8 @@ import org.springframework.util.StringUtils;
 
 /**
  * Default implementation of {@link GraphQlTester}.
+ *
+ * @author Rossen Stoyanchev
  */
 class DefaultGraphQlTester implements GraphQlTester {
 
@@ -68,16 +71,14 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 	static {
 		ClassLoader classLoader = DefaultGraphQlTester.class.getClassLoader();
-		jackson2Present = ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", classLoader) &&
-				ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", classLoader);
+		jackson2Present = ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", classLoader)
+				&& ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", classLoader);
 	}
 
-
 	private final RequestStrategy requestStrategy;
 
 	private final Configuration jsonPathConfig;
 
-
 	DefaultGraphQlTester(WebTestClient client) {
 		this.jsonPathConfig = initJsonPathConfig();
 		this.requestStrategy = new WebTestClientRequestStrategy(client, this.jsonPathConfig);
@@ -92,13 +93,11 @@ class DefaultGraphQlTester implements GraphQlTester {
 		return (jackson2Present ? Jackson2Configuration.create() : Configuration.builder().build());
 	}
 
-
 	@Override
 	public RequestSpec query(String query) {
 		return new DefaultRequestSpec(query);
 	}
 
-
 	/**
 	 * Encapsulate how a GraphQL request is performed.
 	 */
@@ -106,21 +105,24 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		/**
 		 * Perform a request with the given {@link RequestInput} container.
+		 * @param input the request input
+		 * @return the response spec
 		 */
 		GraphQlTester.ResponseSpec execute(RequestInput input);
 
 		/**
 		 * Perform a subscription with the given {@link RequestInput} container.
+		 * @param input the request input
+		 * @return the subscription spec
 		 */
 		GraphQlTester.SubscriptionSpec executeSubscription(RequestInput input);
 
 	}
 
-
 	/**
-	 * {@link RequestStrategy} that works as an HTTP client with requests
-	 * executed through {@link WebTestClient} that in turn may work connect with
-	 * or without a live server for Spring MVC and WebFlux.
+	 * {@link RequestStrategy} that works as an HTTP client with requests executed through
+	 * {@link WebTestClient} that in turn may work connect with or without a live server
+	 * for Spring MVC and WebFlux.
 	 */
 	private static class WebTestClientRequestStrategy implements RequestStrategy {
 
@@ -135,14 +137,9 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		@Override
 		public ResponseSpec execute(RequestInput requestInput) {
-			EntityExchangeResult<byte[]> result = this.client.post()
-					.contentType(MediaType.APPLICATION_JSON)
-					.bodyValue(requestInput)
-					.exchange()
-					.expectStatus().isOk()
-					.expectHeader().contentType(MediaType.APPLICATION_JSON)
-					.expectBody()
-					.returnResult();
+			EntityExchangeResult<byte[]> result = this.client.post().contentType(MediaType.APPLICATION_JSON)
+					.bodyValue(requestInput).exchange().expectStatus().isOk().expectHeader()
+					.contentType(MediaType.APPLICATION_JSON).expectBody().returnResult();
 
 			byte[] bytes = result.getResponseBodyContent();
 			Assert.notNull(bytes, "Expected GraphQL response content");
@@ -155,20 +152,15 @@ class DefaultGraphQlTester implements GraphQlTester {
 		@Override
 		public SubscriptionSpec executeSubscription(RequestInput requestInput) {
 			FluxExchangeResult<TestExecutionResult> exchangeResult = this.client.post()
-					.contentType(MediaType.APPLICATION_JSON)
-					.accept(MediaType.TEXT_EVENT_STREAM)
-					.bodyValue(requestInput)
-					.exchange()
-					.expectStatus().isOk()
-					.expectHeader().contentType(MediaType.TEXT_EVENT_STREAM)
+					.contentType(MediaType.APPLICATION_JSON).accept(MediaType.TEXT_EVENT_STREAM).bodyValue(requestInput)
+					.exchange().expectStatus().isOk().expectHeader().contentType(MediaType.TEXT_EVENT_STREAM)
 					.returnResult(TestExecutionResult.class);
 
-			return new DefaultSubscriptionSpec(
-					exchangeResult.getResponseBody().cast(ExecutionResult.class),
+			return new DefaultSubscriptionSpec(exchangeResult.getResponseBody().cast(ExecutionResult.class),
 					this.jsonPathConfig, exchangeResult::assertWithDiagnostics);
 		}
-	}
 
+	}
 
 	/**
 	 * {@link RequestStrategy} that performs requests directly on {@link GraphQL}.
@@ -181,12 +173,11 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		private static final Duration DEFAULT_TIMEOUT = Duration.ofSeconds(5);
 
-
 		private final WebGraphQlHandler graphQlHandler;
 
 		private final Configuration jsonPathConfig;
 
-		public DirectRequestStrategy(WebGraphQlHandler handler, Configuration jsonPathConfig) {
+		DirectRequestStrategy(WebGraphQlHandler handler, Configuration jsonPathConfig) {
 			this.graphQlHandler = handler;
 			this.jsonPathConfig = jsonPathConfig;
 		}
@@ -205,8 +196,9 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 			List<GraphQLError> errors = result.getErrors();
 			Consumer<Runnable> assertDecorator = assertDecorator(input);
-			assertDecorator.accept(() -> AssertionErrors.assertTrue(
-					"Response has " + errors.size() + " unexpected error(s).", CollectionUtils.isEmpty(errors)));
+			assertDecorator
+					.accept(() -> AssertionErrors.assertTrue("Response has " + errors.size() + " unexpected error(s).",
+							CollectionUtils.isEmpty(errors)));
 
 			return new DefaultSubscriptionSpec(result.getData(), this.jsonPathConfig, assertDecorator);
 		}
@@ -219,7 +211,7 @@ class DefaultGraphQlTester implements GraphQlTester {
 		}
 
 		private Consumer<Runnable> assertDecorator(RequestInput input) {
-			return assertion -> {
+			return (assertion) -> {
 				try {
 					assertion.run();
 				}
@@ -228,13 +220,13 @@ class DefaultGraphQlTester implements GraphQlTester {
 				}
 			};
 		}
-	}
 
+	}
 
 	/**
 	 * {@link RequestSpec} that collects the query, operationName, and variables.
 	 */
-	private class DefaultRequestSpec implements RequestSpec {
+	private final class DefaultRequestSpec implements RequestSpec {
 
 		private final String query;
 
@@ -284,12 +276,12 @@ class DefaultGraphQlTester implements GraphQlTester {
 			RequestInput input = new RequestInput(this.query, this.operationName, this.variables);
 			return DefaultGraphQlTester.this.requestStrategy.executeSubscription(input);
 		}
-	}
 
+	}
 
 	private static class ErrorsContainer {
 
-		private static final Predicate<GraphQLError> MATCH_ALL_PREDICATE = error -> true;
+		private static final Predicate<GraphQLError> MATCH_ALL_PREDICATE = (error) -> true;
 
 		private final List<TestGraphQlError> errors;
 
@@ -302,32 +294,35 @@ class DefaultGraphQlTester implements GraphQlTester {
 			this.assertDecorator = assertDecorator;
 		}
 
-		public void doAssert(Runnable task) {
+		void doAssert(Runnable task) {
 			this.assertDecorator.accept(task);
 		}
 
-		public void filterErrors(Predicate<GraphQLError> errorPredicate) {
-			this.errors.forEach(error -> error.filter(errorPredicate));
+		void filterErrors(Predicate<GraphQLError> errorPredicate) {
+			this.errors.forEach((error) -> error.filter(errorPredicate));
 		}
 
-		public void consumeErrors(Consumer<List<GraphQLError>> consumer) {
+		void consumeErrors(Consumer<List<GraphQLError>> consumer) {
 			filterErrors(MATCH_ALL_PREDICATE);
 			consumer.accept(new ArrayList<>(this.errors));
 		}
 
-		public void verifyErrors() {
+		void verifyErrors() {
 
-			List<TestGraphQlError> unexpected =
-					this.errors.stream().filter(error -> !error.isExpected()).collect(Collectors.toList());
+			List<TestGraphQlError> unexpected = this.errors.stream().filter((error) -> !error.isExpected())
+					.collect(Collectors.toList());
 
-			this.assertDecorator.accept(() -> AssertionErrors.assertTrue(
-					"Response has " + unexpected.size() + " unexpected error(s)" +
-							(unexpected.size() != this.errors.size() ? " of " + this.errors.size() + " total" : "") + ". " +
-							"If expected, please use ResponseSpec#errors to filter them out: " + unexpected,
-					CollectionUtils.isEmpty(unexpected)));
+			this.assertDecorator
+					.accept(() -> AssertionErrors.assertTrue(
+							"Response has " + unexpected.size() + " unexpected error(s)"
+									+ ((unexpected.size() != this.errors.size())
+											? " of " + this.errors.size() + " total" : "")
+									+ ". " + "If expected, please use ResponseSpec#errors to filter them out: "
+									+ unexpected,
+							CollectionUtils.isEmpty(unexpected)));
 		}
-	}
 
+	}
 
 	/**
 	 * Container for a GraphQL response with access to data and errors.
@@ -349,18 +344,19 @@ class DefaultGraphQlTester implements GraphQlTester {
 		private static List<TestGraphQlError> readErrors(DocumentContext documentContext) {
 			Assert.notNull(documentContext, "DocumentContext is required");
 			try {
-				return documentContext.read(ERRORS_PATH, new TypeRef<List<TestGraphQlError>>() {});
+				return documentContext.read(ERRORS_PATH, new TypeRef<List<TestGraphQlError>>() {
+				});
 			}
 			catch (PathNotFoundException ex) {
 				return Collections.emptyList();
 			}
 		}
 
-		public String jsonContent() {
+		String jsonContent() {
 			return this.jsonContent;
 		}
 
-		public String jsonContent(JsonPath jsonPath) {
+		String jsonContent(JsonPath jsonPath) {
 			try {
 				Object content = this.documentContext.read(jsonPath);
 				return this.documentContext.configuration().jsonProvider().toJson(content);
@@ -370,25 +366,24 @@ class DefaultGraphQlTester implements GraphQlTester {
 			}
 		}
 
-		public <T> T read(JsonPath jsonPath, TypeRef<T> typeRef) {
+		<T> T read(JsonPath jsonPath, TypeRef<T> typeRef) {
 			return this.documentContext.read(jsonPath, typeRef);
 		}
-	}
 
+	}
 
 	/**
 	 * {@link ResponseSpec} that operates on the response from a GraphQL HTTP request.
 	 */
-	private static class DefaultResponseSpec implements ResponseSpec, ErrorSpec {
+	private static final class DefaultResponseSpec implements ResponseSpec, ErrorSpec {
 
 		private final ResponseContainer responseContainer;
 
 		/**
 		 * Class constructor.
 		 * @param documentContext the parsed response content
-		 * @param assertDecorator decorator to apply around assertions, e.g. to
-		 * add extra contextual information such as HTTP request and response
-		 * body details
+		 * @param assertDecorator decorator to apply around assertions, e.g. to add extra
+		 * contextual information such as HTTP request and response body details
 		 */
 		private DefaultResponseSpec(DocumentContext documentContext, Consumer<Runnable> assertDecorator) {
 			this.responseContainer = new ResponseContainer(documentContext, assertDecorator);
@@ -422,8 +417,8 @@ class DefaultGraphQlTester implements GraphQlTester {
 			this.responseContainer.consumeErrors(consumer);
 			return this;
 		}
-	}
 
+	}
 
 	/**
 	 * {@link PathSpec} implementation.
@@ -438,7 +433,6 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		private final JsonPathExpectationsHelper pathHelper;
 
-
 		DefaultPathSpec(String path, ResponseContainer responseContainer) {
 			Assert.notNull(path, "`path` is required");
 			Assert.notNull(responseContainer, "ResponseContainer is required");
@@ -458,7 +452,6 @@ class DefaultGraphQlTester implements GraphQlTester {
 			return JsonPath.compile(path);
 		}
 
-
 		@Override
 		public PathSpec path(String path) {
 			return new DefaultPathSpec(path, this.responseContainer);
@@ -466,29 +459,26 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		@Override
 		public PathSpec pathExists() {
-			this.responseContainer.doAssert(
-					() -> this.pathHelper.hasJsonPath(this.responseContainer.jsonContent()));
+			this.responseContainer.doAssert(() -> this.pathHelper.hasJsonPath(this.responseContainer.jsonContent()));
 			return this;
 		}
 
 		@Override
 		public PathSpec pathDoesNotExist() {
-			this.responseContainer.doAssert(
-					() -> this.pathHelper.doesNotHaveJsonPath(this.responseContainer.jsonContent()));
+			this.responseContainer
+					.doAssert(() -> this.pathHelper.doesNotHaveJsonPath(this.responseContainer.jsonContent()));
 			return this;
 		}
 
 		@Override
 		public PathSpec valueExists() {
-			this.responseContainer.doAssert(
-					() -> this.pathHelper.exists(this.responseContainer.jsonContent()));
+			this.responseContainer.doAssert(() -> this.pathHelper.exists(this.responseContainer.jsonContent()));
 			return this;
 		}
 
 		@Override
 		public PathSpec valueDoesNotExist() {
-			this.responseContainer.doAssert(
-					() -> this.pathHelper.doesNotExist(this.responseContainer.jsonContent()));
+			this.responseContainer.doAssert(() -> this.pathHelper.doesNotExist(this.responseContainer.jsonContent()));
 			return this;
 		}
 
@@ -507,8 +497,8 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		@Override
 		public PathSpec valueIsNotEmpty() {
-			this.responseContainer.doAssert(
-					() -> this.pathHelper.assertValueIsNotEmpty(this.responseContainer.jsonContent()));
+			this.responseContainer
+					.doAssert(() -> this.pathHelper.assertValueIsNotEmpty(this.responseContainer.jsonContent()));
 			return this;
 		}
 
@@ -555,18 +545,17 @@ class DefaultGraphQlTester implements GraphQlTester {
 					new JsonExpectationsHelper().assertJsonEqual(expected, actual, strict);
 				}
 				catch (AssertionError ex) {
-					throw new AssertionError(ex.getMessage() + "\n\n" +
-							"Expected JSON content:\n'" + expected + "'\n\n" +
-							"Actual JSON content:\n'" + actual + "'\n\n" +
-							"Input path: '" + this.inputPath + "'\n", ex);
+					throw new AssertionError(ex.getMessage() + "\n\n" + "Expected JSON content:\n'" + expected + "'\n\n"
+							+ "Actual JSON content:\n'" + actual + "'\n\n" + "Input path: '" + this.inputPath + "'\n",
+							ex);
 				}
 				catch (Exception ex) {
 					throw new AssertionError("JSON parsing error", ex);
 				}
 			});
 		}
-	}
 
+	}
 
 	/**
 	 * {@link EntitySpec} implementation.
@@ -604,22 +593,19 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		@Override
 		public <T extends S> T isEqualTo(Object expected) {
-			this.responseContainer.doAssert(
-					() -> AssertionErrors.assertEquals(this.inputPath, expected, this.entity));
+			this.responseContainer.doAssert(() -> AssertionErrors.assertEquals(this.inputPath, expected, this.entity));
 			return self();
 		}
 
 		@Override
 		public <T extends S> T isNotEqualTo(Object other) {
-			this.responseContainer.doAssert(
-					() -> AssertionErrors.assertNotEquals(this.inputPath, other, this.entity));
+			this.responseContainer.doAssert(() -> AssertionErrors.assertNotEquals(this.inputPath, other, this.entity));
 			return self();
 		}
 
 		@Override
 		public <T extends S> T isSameAs(Object expected) {
-			this.responseContainer.doAssert(
-					() -> AssertionErrors.assertTrue(this.inputPath, expected == this.entity));
+			this.responseContainer.doAssert(() -> AssertionErrors.assertTrue(this.inputPath, expected == this.entity));
 			return self();
 		}
 
@@ -631,8 +617,8 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		@Override
 		public <T extends S> T matches(Predicate<D> predicate) {
-			this.responseContainer.doAssert(
-					() -> AssertionErrors.assertTrue(this.inputPath, predicate.test(this.entity)));
+			this.responseContainer
+					.doAssert(() -> AssertionErrors.assertTrue(this.inputPath, predicate.test(this.entity)));
 			return self();
 		}
 
@@ -651,8 +637,8 @@ class DefaultGraphQlTester implements GraphQlTester {
 		private <T extends S> T self() {
 			return (T) this;
 		}
-	}
 
+	}
 
 	/**
 	 * {@link ListEntitySpec} implementation.
@@ -669,8 +655,7 @@ class DefaultGraphQlTester implements GraphQlTester {
 		public ListEntitySpec<E> contains(E... elements) {
 			doAssert(() -> {
 				List<E> expected = Arrays.asList(elements);
-				AssertionErrors.assertTrue(
-						"List at path '" + getInputPath() + "' does not contain " + expected,
+				AssertionErrors.assertTrue("List at path '" + getInputPath() + "' does not contain " + expected,
 						(getEntity() != null && getEntity().containsAll(expected)));
 			});
 			return this;
@@ -702,36 +687,32 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		@Override
 		public ListEntitySpec<E> hasSize(int size) {
-			doAssert(() ->
-					AssertionErrors.assertTrue(
-							"List at path '" + getInputPath() + "' should have size " + size,
-							(getEntity() != null && getEntity().size() == size)));
+			doAssert(() -> AssertionErrors.assertTrue("List at path '" + getInputPath() + "' should have size " + size,
+					(getEntity() != null && getEntity().size() == size)));
 			return this;
 		}
 
 		@Override
 		public ListEntitySpec<E> hasSizeLessThan(int boundary) {
-			doAssert(() ->
-					AssertionErrors.assertTrue(
-							"List at path '" + getInputPath() + "' should have size less than " + boundary,
-							(getEntity() != null && getEntity().size() < boundary)));
+			doAssert(() -> AssertionErrors.assertTrue(
+					"List at path '" + getInputPath() + "' should have size less than " + boundary,
+					(getEntity() != null && getEntity().size() < boundary)));
 			return this;
 		}
 
 		@Override
 		public ListEntitySpec<E> hasSizeGreaterThan(int boundary) {
-			doAssert(() ->
-					AssertionErrors.assertTrue(
-							"List at path '" + getInputPath() + "' should have size greater than " + boundary,
-							(getEntity() != null && getEntity().size() > boundary)));
+			doAssert(() -> AssertionErrors.assertTrue(
+					"List at path '" + getInputPath() + "' should have size greater than " + boundary,
+					(getEntity() != null && getEntity().size() > boundary)));
 			return this;
 		}
+
 	}
 
-
 	/**
-	 * {@link SubscriptionSpec} implementation that operates on a
-	 * {@link Publisher} of {@link ExecutionResult}.
+	 * {@link SubscriptionSpec} implementation that operates on a {@link Publisher} of
+	 * {@link ExecutionResult}.
 	 */
 	private static class DefaultSubscriptionSpec implements SubscriptionSpec {
 
@@ -741,8 +722,8 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		private final Consumer<Runnable> assertDecorator;
 
-		<T> DefaultSubscriptionSpec(
-				Publisher<ExecutionResult> publisher, Configuration jsonPathConfig, Consumer<Runnable> decorator) {
+		<T> DefaultSubscriptionSpec(Publisher<ExecutionResult> publisher, Configuration jsonPathConfig,
+				Consumer<Runnable> decorator) {
 
 			this.publisher = publisher;
 			this.jsonPathConfig = jsonPathConfig;
@@ -751,22 +732,21 @@ class DefaultGraphQlTester implements GraphQlTester {
 
 		@Override
 		public Flux<ResponseSpec> toFlux() {
-			return Flux.from(this.publisher).map(result -> {
+			return Flux.from(this.publisher).map((result) -> {
 				DocumentContext context = JsonPath.parse(result.toSpecification(), this.jsonPathConfig);
 				return new DefaultResponseSpec(context, this.assertDecorator);
 			});
 		}
-	}
 
+	}
 
 	private static class Jackson2Configuration {
 
 		static Configuration create() {
-			return Configuration.builder()
-					.jsonProvider(new JacksonJsonProvider())
-					.mappingProvider(new JacksonMappingProvider())
-					.build();
+			return Configuration.builder().jsonProvider(new JacksonJsonProvider())
+					.mappingProvider(new JacksonMappingProvider()).build();
 		}
+
 	}
 
 }
diff --git a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/GraphQlTester.java b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/GraphQlTester.java
index e8abd8fc..d80a0402 100644
--- a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/GraphQlTester.java
+++ b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/GraphQlTester.java
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.test.tester;
 
 import java.util.List;
@@ -29,13 +30,12 @@ import org.springframework.lang.Nullable;
 import org.springframework.test.web.reactive.server.WebTestClient;
 
 /**
- * Main entry point for testing GraphQL with requests performed either as an
- * HTTP client  via {@link WebTestClient} or directly via a
- * {@link WebGraphQlHandler}.
+ * Main entry point for testing GraphQL with requests performed either as an HTTP client
+ * via {@link WebTestClient} or directly via a {@link WebGraphQlHandler}.
  *
  *
- * <p>GraphQL requests to Spring MVC without an HTTP server:
- * <pre class="code">
+ * <p>
+ * GraphQL requests to Spring MVC without an HTTP server: <pre class="code">
  * &#064;SpringBootTest
  * &#064;AutoConfigureMockMvc
  * public class MyTests {
@@ -49,8 +49,8 @@ import org.springframework.test.web.reactive.server.WebTestClient;
  *  }
  * </pre>
  *
- * <p>GraphQL requests to Spring WebFlux without an HTTP server:
- * <pre class="code">
+ * <p>
+ * GraphQL requests to Spring WebFlux without an HTTP server: <pre class="code">
  * &#064;SpringBootTest
  * &#064;AutoConfigureWebTestClient
  * public class MyTests {
@@ -63,8 +63,8 @@ import org.springframework.test.web.reactive.server.WebTestClient;
  *  }
  * </pre>
  *
- * <p>GraphQL requests to a running server:
- * <pre class="code">
+ * <p>
+ * GraphQL requests to a running server: <pre class="code">
  * &#064;SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
  * public class MyTests {
  *
@@ -76,8 +76,8 @@ import org.springframework.test.web.reactive.server.WebTestClient;
  *  }
  * </pre>
  *
- * <p>GraphQL requests to any {@link WebGraphQlHandler}:
- * <pre class="code">
+ * <p>
+ * GraphQL requests to any {@link WebGraphQlHandler}: <pre class="code">
  * &#064;SpringBootTest
  * public class MyTests {
  *
@@ -88,24 +88,26 @@ import org.springframework.test.web.reactive.server.WebTestClient;
  *      this.graphQlTester = GraphQlTester.create(handler);
  *  }
  * </pre>
+ *
+ * @author Rossen Stoyanchev
+ * @since 1.0.0
  */
 public interface GraphQlTester {
 
 	/**
-	 * Prepare to perform a GraphQL request with the given operation which may
-	 * be a query, mutation, or a subscription.
+	 * Prepare to perform a GraphQL request with the given operation which may be a query,
+	 * mutation, or a subscription.
 	 * @param query the operation to be performed
 	 * @return spec for response assertions
 	 * @throws AssertionError if the response status is not 200 (OK)
 	 */
 	RequestSpec query(String query);
 
-
 	/**
-	 * Create a {@code GraphQlTester} that performs GraphQL requests as an HTTP
-	 * client through the given {@link WebTestClient}. Depending on how the
-	 * {@code WebTestClient} is set up, tests may be with or without a server.
-	 * See setup examples in class-level Javadoc.
+	 * Create a {@code GraphQlTester} that performs GraphQL requests as an HTTP client
+	 * through the given {@link WebTestClient}. Depending on how the {@code WebTestClient}
+	 * is set up, tests may be with or without a server. See setup examples in class-level
+	 * Javadoc.
 	 * @param client the web client to perform requests with
 	 * @return the created {@code GraphQlTester} instance
 	 */
@@ -114,8 +116,8 @@ public interface GraphQlTester {
 	}
 
 	/**
-	 * Create a {@code GraphQlTester} that performs GraphQL requests through
-	 * the given {@link WebGraphQlHandler}.
+	 * Create a {@code GraphQlTester} that performs GraphQL requests through the given
+	 * {@link WebGraphQlHandler}.
 	 * @param handler the handler to execute requests with
 	 * @return the created {@code GraphQlTester} instance
 	 */
@@ -123,19 +125,17 @@ public interface GraphQlTester {
 		return new DefaultGraphQlTester(handler);
 	}
 
-
 	/**
 	 * Declare options to perform a GraphQL request.
 	 */
 	interface ExecuteSpec {
 
 		/**
-		 * Execute the GraphQL request and return a spec for further inspection
-		 * of response data and errors.
-		 *
+		 * Execute the GraphQL request and return a spec for further inspection of
+		 * response data and errors.
 		 * @return options for asserting the response
-		 * @throws AssertionError if the request is performed over HTTP and the
-		 * response status is not 200 (OK).
+		 * @throws AssertionError if the request is performed over HTTP and the response
+		 * status is not 200 (OK).
 		 */
 		ResponseSpec execute();
 
@@ -145,18 +145,16 @@ public interface GraphQlTester {
 		void executeAndVerify();
 
 		/**
-		 * Execute the GraphQL request as a subscription and return a spec with
-		 * options to transform the result stream.
-		 *
+		 * Execute the GraphQL request as a subscription and return a spec with options to
+		 * transform the result stream.
 		 * @return spec with options to transform the subscription result stream
-		 * @throws AssertionError if the request is performed over HTTP and the
-		 * response status is not 200 (OK).
+		 * @throws AssertionError if the request is performed over HTTP and the response
+		 * status is not 200 (OK).
 		 */
 		SubscriptionSpec executeSubscription();
 
 	}
 
-
 	/**
 	 * Declare options to gather input for a GraphQL request and execute it.
 	 */
@@ -164,20 +162,27 @@ public interface GraphQlTester {
 
 		/**
 		 * Set the operation name.
+		 * @param name the operation name
+		 * @return this request spec
 		 */
 		RequestSpec operationName(@Nullable String name);
 
 		/**
 		 * Add a variable.
+		 * @param name the variable name
+		 * @param value the variable value
+		 * @return this request spec
 		 */
 		RequestSpec variable(String name, Object value);
 
 		/**
 		 * Modify variables by accessing the underlying map.
+		 * @param variablesConsumer a callback for the map of variables
+		 * @return this request spec
 		 */
 		RequestSpec variables(Consumer<Map<String, Object>> variablesConsumer);
-	}
 
+	}
 
 	/**
 	 * Declare options to switch to different part of the GraphQL response.
@@ -185,20 +190,19 @@ public interface GraphQlTester {
 	interface TraverseSpec {
 
 		/**
-		 * Switch to a path under the "data" section of the GraphQL response.
-		 * The path can be an operation root type name, e.g. "project", or a
-		 * nested path such as "project.name", or any
+		 * Switch to a path under the "data" section of the GraphQL response. The path can
+		 * be an operation root type name, e.g. "project", or a nested path such as
+		 * "project.name", or any
 		 * <a href="https://github.com/jayway/JsonPath">JsonPath</a>.
-		 *
 		 * @param path the path to switch to
 		 * @return spec for asserting the content under the given path
 		 * @throws AssertionError if the GraphQL response contains
-		 * <a href="https://spec.graphql.org/June2018/#sec-Errors">errors</a>
-		 * that have not be checked via {@link ResponseSpec#errors()}
+		 * <a href="https://spec.graphql.org/June2018/#sec-Errors">errors</a> that have
+		 * not be checked via {@link ResponseSpec#errors()}
 		 */
 		PathSpec path(String path);
-	}
 
+	}
 
 	/**
 	 * Declare options to check the data and errors of a GraphQL response.
@@ -206,15 +210,15 @@ public interface GraphQlTester {
 	interface ResponseSpec extends TraverseSpec {
 
 		/**
-		 * Return a spec to filter out or inspect errors. This must be used
-		 * before traversing to a {@link #path(String)} if some errors are
-		 * expected and need to be filtered out.
+		 * Return a spec to filter out or inspect errors. This must be used before
+		 * traversing to a {@link #path(String)} if some errors are expected and need to
+		 * be filtered out.
+		 * @return the error spec
 		 */
 		ErrorSpec errors();
 
 	}
 
-
 	/**
 	 * Declare options available to assert data at a given path.
 	 */
@@ -233,8 +237,8 @@ public interface GraphQlTester {
 		PathSpec pathDoesNotExist();
 
 		/**
-		 * Assert a value exists at the given path where the value is any
-		 * {@code non-null} value, possibly an empty array or map.
+		 * Assert a value exists at the given path where the value is any {@code non-null}
+		 * value, possibly an empty array or map.
 		 * @return spec to assert the converted entity with
 		 */
 		PathSpec valueExists();
@@ -246,22 +250,22 @@ public interface GraphQlTester {
 		PathSpec valueDoesNotExist();
 
 		/**
-		 * Assert the value at the given path does not exist or is empty as defined
-		 * in {@link org.springframework.util.ObjectUtils#isEmpty(Object)}.
+		 * Assert the value at the given path does not exist or is empty as defined in
+		 * {@link org.springframework.util.ObjectUtils#isEmpty(Object)}.
 		 * @return spec to assert the converted entity with
 		 * @see org.springframework.util.ObjectUtils#isEmpty(Object)
 		 */
 		PathSpec valueIsEmpty();
 
 		/**
-		 * Assert the value at the given path is not {@link #valueIsEmpty()}
+		 * Assert the value at the given path is not {@link #valueIsEmpty()}.
 		 * @return spec to assert the converted entity with
 		 */
 		PathSpec valueIsNotEmpty();
 
 		/**
 		 * Convert the data at the given path to the target type.
- 		 * @param entityType the type to convert to
+		 * @param entityType the type to convert to
 		 * @param <D> the target entity type
 		 * @return spec to assert the converted entity with
 		 */
@@ -292,33 +296,36 @@ public interface GraphQlTester {
 		<D> ListEntitySpec<D> entityList(ParameterizedTypeReference<D> elementType);
 
 		/**
-		 * Parse the JSON at the given path and the given expected JSON and assert
-		 * that the two are "similar".
-		 * <p>Use of this option requires the
-		 * <a href="https://jsonassert.skyscreamer.org/">JSONassert</a> library
-		 * on to be on the classpath.
+		 * Parse the JSON at the given path and the given expected JSON and assert that
+		 * the two are "similar".
+		 * <p>
+		 * Use of this option requires the
+		 * <a href="https://jsonassert.skyscreamer.org/">JSONassert</a> library on to be
+		 * on the classpath.
 		 * @param expectedJson the expected JSON
 		 * @return spec to specify a different path
-		 * @see org.springframework.test.util.JsonExpectationsHelper#assertJsonEqual(String, String)
+		 * @see org.springframework.test.util.JsonExpectationsHelper#assertJsonEqual(String,
+		 * String)
 		 */
 		TraverseSpec matchesJson(String expectedJson);
 
 		/**
-		 * Parse the JSON at the given path and the given expected JSON and assert
-		 * that the two are "similar" so they contain the same attribute-value
-		 * pairs regardless of formatting, along with lenient checking, e.g.
-		 * extensible and non-strict array ordering.
+		 * Parse the JSON at the given path and the given expected JSON and assert that
+		 * the two are "similar" so they contain the same attribute-value pairs regardless
+		 * of formatting, along with lenient checking, e.g. extensible and non-strict
+		 * array ordering.
 		 * @param expectedJson the expected JSON
 		 * @return spec to specify a different path
-		 * @see org.springframework.test.util.JsonExpectationsHelper#assertJsonEqual(String, String, boolean)
+		 * @see org.springframework.test.util.JsonExpectationsHelper#assertJsonEqual(String,
+		 * String, boolean)
 		 */
 		TraverseSpec matchesJsonStrictly(String expectedJson);
 
 	}
 
-
 	/**
 	 * Declare options available to assert data converted to an entity.
+	 *
 	 * @param <D> the entity type
 	 * @param <S> the spec type, including subtypes
 	 */
@@ -367,21 +374,23 @@ public interface GraphQlTester {
 		/**
 		 * Perform any assertions on the converted entity, e.g. via AssertJ.
 		 * @param consumer the consumer to inspect the entity with
+		 * @param <T> the spec type
 		 * @return the same spec for more assertions
 		 */
 		<T extends S> T satisfies(Consumer<D> consumer);
 
 		/**
 		 * Return the converted entity.
+		 * @return the converter entity
 		 */
 		D get();
 
 	}
 
-
 	/**
-	 * Extension of {@link EntitySpec} with options available to assert data
-	 * converted to a List of entities.
+	 * Extension of {@link EntitySpec} with options available to assert data converted to
+	 * a List of entities.
+	 *
 	 * @param <E> the type of elements in the list
 	 */
 	interface ListEntitySpec<E> extends EntitySpec<List<E>, ListEntitySpec<E>> {
@@ -433,16 +442,15 @@ public interface GraphQlTester {
 
 	}
 
-
 	/**
-	 * Declare options to filter out expected errors or inspect all errors and
-	 * verify there are no unexpected errors.
+	 * Declare options to filter out expected errors or inspect all errors and verify
+	 * there are no unexpected errors.
 	 */
 	interface ErrorSpec {
 
 		/**
-		 * Add a filter for expected errors. All errors that match the predicate
-		 * are treated as expected and ignored on {@link #verify()} or when
+		 * Add a filter for expected errors. All errors that match the predicate are
+		 * treated as expected and ignored on {@link #verify()} or when
 		 * {@link TraverseSpec#path(String) traversing} to a data path.
 		 * @param errorPredicate the predicate to add
 		 * @return the same spec to add more filters before {@link #verify()}
@@ -450,17 +458,16 @@ public interface GraphQlTester {
 		ErrorSpec filter(Predicate<GraphQLError> errorPredicate);
 
 		/**
-		 * Verify there are either no errors or that there no unexpected errors
-		 * that have not been {@link #filter(Predicate) filtered out}.
+		 * Verify there are either no errors or that there no unexpected errors that have
+		 * not been {@link #filter(Predicate) filtered out}.
 		 * @return a spec to switch to a data path
 		 */
 		TraverseSpec verify();
 
 		/**
-		 * Inspect <a href="https://spec.graphql.org/June2018/#sec-Errors">errors</a>
-		 * in the response, if any. Use of this method effectively suppresses
-		 * all errors and allows {@link TraverseSpec#path(String) traversing} to a
-		 * data path.
+		 * Inspect <a href="https://spec.graphql.org/June2018/#sec-Errors">errors</a> in
+		 * the response, if any. Use of this method effectively suppresses all errors and
+		 * allows {@link TraverseSpec#path(String) traversing} to a data path.
 		 * @param errorsConsumer to inspect errors with
 		 * @return a spec to switch to a data path
 		 */
@@ -468,30 +475,29 @@ public interface GraphQlTester {
 
 	}
 
-
 	/**
 	 * Declare options available to assert a GraphQL Subscription response.
 	 */
 	interface SubscriptionSpec {
 
 		/**
-		 * Return a {@link Flux} of entities converted from some part of the data
-		 * in each subscription event.
+		 * Return a {@link Flux} of entities converted from some part of the data in each
+		 * subscription event.
 		 * @param path a path into the data of each subscription event
 		 * @param entityType the type to convert data to
 		 * @param <T> the entity type
-		 * @return a {@code Flux} of entities that can be further inspected,
-		 * e.g. with {@code reactor.test.StepVerifier}
+		 * @return a {@code Flux} of entities that can be further inspected, e.g. with
+		 * {@code reactor.test.StepVerifier}
 		 */
 		default <T> Flux<T> toFlux(String path, Class<T> entityType) {
-			return toFlux().map(spec -> spec.path(path).entity(entityType).get());
+			return toFlux().map((spec) -> spec.path(path).entity(entityType).get());
 		}
 
 		/**
-		 * Return a {@link Flux} of {@link ResponseSpec} instances, each
-		 * representing an individual subscription event.
-		 * @return a {@code Flux} of {@code ResponseSpec} instances that can be
-		 * further inspected, e.g. with {@code reactor.test.StepVerifier}
+		 * Return a {@link Flux} of {@link ResponseSpec} instances, each representing an
+		 * individual subscription event.
+		 * @return a {@code Flux} of {@code ResponseSpec} instances that can be further
+		 * inspected, e.g. with {@code reactor.test.StepVerifier}
 		 */
 		Flux<ResponseSpec> toFlux();
 
diff --git a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TestExecutionResult.java b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TestExecutionResult.java
index 7a6572fc..df1f7c3c 100644
--- a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TestExecutionResult.java
+++ b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TestExecutionResult.java
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.test.tester;
 
 import java.util.ArrayList;
@@ -27,6 +28,9 @@ import graphql.GraphQLError;
 
 /**
  * {@link GraphQLError} with setters for deserialization.
+ *
+ * @author Rossen Stoyanchev
+ * @since 1.0.0
  */
 public class TestExecutionResult implements ExecutionResult {
 
@@ -36,7 +40,6 @@ public class TestExecutionResult implements ExecutionResult {
 
 	private Map<Object, Object> extensions = Collections.emptyMap();
 
-
 	public void setData(Object data) {
 		this.data = data;
 	}
@@ -72,8 +75,7 @@ public class TestExecutionResult implements ExecutionResult {
 
 	@Override
 	public Map<String, Object> toSpecification() {
-		ExecutionResultImpl.Builder builder = ExecutionResultImpl.newExecutionResult()
-				.addErrors(this.errors)
+		ExecutionResultImpl.Builder builder = ExecutionResultImpl.newExecutionResult().addErrors(this.errors)
 				.extensions(this.extensions);
 
 		if (isDataPresent()) {
@@ -82,4 +84,5 @@ public class TestExecutionResult implements ExecutionResult {
 
 		return builder.build().toSpecification();
 	}
+
 }
diff --git a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TestGraphQlError.java b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TestGraphQlError.java
index 9afb0e91..a0acf243 100644
--- a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TestGraphQlError.java
+++ b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TestGraphQlError.java
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.test.tester;
 
 import java.util.List;
@@ -28,6 +29,8 @@ import graphql.language.SourceLocation;
 
 /**
  * {@link GraphQLError} with setters to use for deserialization.
+ *
+ * @author Rossen Stoyanchev
  */
 class TestGraphQlError implements GraphQLError {
 
@@ -43,9 +46,7 @@ class TestGraphQlError implements GraphQLError {
 
 	private boolean expected;
 
-
-
-	public void setMessage(String message) {
+	void setMessage(String message) {
 		this.message = message;
 	}
 
@@ -54,7 +55,7 @@ class TestGraphQlError implements GraphQLError {
 		return this.message;
 	}
 
-	public void setLocations(List<TestSourceLocation> locations) {
+	void setLocations(List<TestSourceLocation> locations) {
 		this.locations = TestSourceLocation.toSourceLocations(locations);
 	}
 
@@ -63,7 +64,7 @@ class TestGraphQlError implements GraphQLError {
 		return this.locations;
 	}
 
-	public void setErrorType(ErrorClassification errorType) {
+	void setErrorType(ErrorClassification errorType) {
 		this.errorType = errorType;
 	}
 
@@ -72,7 +73,7 @@ class TestGraphQlError implements GraphQLError {
 		return this.errorType;
 	}
 
-	public void setPath(List<Object> path) {
+	void setPath(List<Object> path) {
 		this.path = path;
 	}
 
@@ -81,7 +82,7 @@ class TestGraphQlError implements GraphQLError {
 		return this.path;
 	}
 
-	public void setExtensions(Map<String, Object> extensions) {
+	void setExtensions(Map<String, Object> extensions) {
 		this.extensions = extensions;
 	}
 
@@ -92,8 +93,9 @@ class TestGraphQlError implements GraphQLError {
 
 	/**
 	 * Whether the error is marked as filtered out as expected.
+	 * @return whether the error is marked as expected
 	 */
-	public boolean isExpected() {
+	boolean isExpected() {
 		return this.expected;
 	}
 
@@ -117,6 +119,7 @@ class TestGraphQlError implements GraphQLError {
 
 	/**
 	 * Mark this error as expected if it matches the predicate.
+	 * @param predicate the error predicate
 	 */
 	void filter(Predicate<GraphQLError> predicate) {
 		this.expected |= predicate.test(this);
@@ -127,8 +130,7 @@ class TestGraphQlError implements GraphQLError {
 		return toSpecification().toString();
 	}
 
-
-	private static class TestSourceLocation {
+	private static final class TestSourceLocation {
 
 		private int line;
 
@@ -136,35 +138,36 @@ class TestGraphQlError implements GraphQLError {
 
 		private String sourceName;
 
-
-		public void setLine(int line) {
+		void setLine(int line) {
 			this.line = line;
 		}
 
-		public int getLine() {
+		int getLine() {
 			return this.line;
 		}
 
-		public void setColumn(int column) {
+		void setColumn(int column) {
 			this.column = column;
 		}
 
-		public int getColumn() {
+		int getColumn() {
 			return this.column;
 		}
 
-		public void setSourceName(String sourceName) {
+		void setSourceName(String sourceName) {
 			this.sourceName = sourceName;
 		}
 
-		public String getSourceName() {
+		String getSourceName() {
 			return this.sourceName;
 		}
 
-		public static List<SourceLocation> toSourceLocations(List<TestSourceLocation> locations) {
+		static List<SourceLocation> toSourceLocations(List<TestSourceLocation> locations) {
 			return locations.stream()
-					.map(location -> new SourceLocation(location.line, location.column, location.sourceName))
+					.map((location) -> new SourceLocation(location.line, location.column, location.sourceName))
 					.collect(Collectors.toList());
 		}
+
 	}
+
 }
diff --git a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TypeRefAdapter.java b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TypeRefAdapter.java
index c5ae70db..17f67a2d 100644
--- a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TypeRefAdapter.java
+++ b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/TypeRefAdapter.java
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.test.tester;
 
 import java.lang.reflect.Type;
@@ -23,14 +24,16 @@ import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.core.ResolvableType;
 
 /**
- * {@link TypeRef} with a {@link #getType() type} that is given rather than
- * obtained from the declared generic type information.
+ * {@link TypeRef} with a {@link #getType() type} that is given rather than obtained from
+ * the declared generic type information.
+ *
+ * @param <T> the referenced type
+ * @author Rossen Stoyanchev
  */
 class TypeRefAdapter<T> extends TypeRef<T> {
 
 	private final Type type;
 
-
 	TypeRefAdapter(Class<T> clazz) {
 		this.type = clazz;
 	}
@@ -47,7 +50,6 @@ class TypeRefAdapter<T> extends TypeRef<T> {
 		this.type = ResolvableType.forClassWithGenerics(clazz, ResolvableType.forType(generic)).getType();
 	}
 
-
 	@Override
 	public Type getType() {
 		return this.type;
diff --git a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/package-info.java b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/package-info.java
index 4e60f5d1..67cbae3b 100644
--- a/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/package-info.java
+++ b/spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/package-info.java
@@ -13,6 +13,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
+/**
+ * GraphQL client testing support.
+ */
 @NonNullApi
 @NonNullFields
 package org.springframework.graphql.test.tester;
diff --git a/spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/GraphQlTesterTests.java b/spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/GraphQlTesterTests.java
index 94bfb660..a8f2829e 100644
--- a/spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/GraphQlTesterTests.java
+++ b/spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/GraphQlTesterTests.java
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.test.tester;
 
 import java.util.Arrays;
@@ -51,8 +52,8 @@ import org.springframework.util.StringUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
 
 /**
  * Tests for {@link GraphQlTester} parameterized to:
@@ -61,20 +62,18 @@ import static org.mockito.Mockito.when;
  * <li>Use mock {@link WebGraphQlHandler} to return a preset {@link ExecutionResult}.
  * </ul>
  *
- * <p>There is no actual handling via {@link graphql.GraphQL} in either scenario.
- * The main focus is to verify {@link GraphQlTester} request preparation and
- * response handling.
+ * <p>
+ * There is no actual handling via {@link graphql.GraphQL} in either scenario. The main
+ * focus is to verify {@link GraphQlTester} request preparation and response handling.
  */
 public class GraphQlTesterTests {
 
 	private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
 
-
 	public static Stream<GraphQlTesterSetup> argumentSource() {
 		return Stream.of(new MockWebServerSetup(), new MockWebGraphQlHandlerSetup());
 	}
 
-
 	@ParameterizedTest
 	@MethodSource("argumentSource")
 	void pathAndValueExistsAndEmptyChecks(GraphQlTesterSetup setup) throws Exception {
@@ -88,7 +87,7 @@ public class GraphQlTesterTests {
 		spec.path("me.friends").valueIsEmpty();
 		spec.path("hero").pathDoesNotExist().valueDoesNotExist().valueIsEmpty();
 
-		setup.verifyRequest(input -> assertThat(input.getQuery()).contains(query));
+		setup.verifyRequest((input) -> assertThat(input.getQuery()).contains(query));
 		setup.shutdown();
 	}
 
@@ -103,13 +102,13 @@ public class GraphQlTesterTests {
 
 		spec.path("").matchesJson("{\"me\": {\"name\":\"Luke Skywalker\",\"friends\":[]}}");
 		spec.path("me").matchesJson("{\"name\":\"Luke Skywalker\"}");
-		spec.path("me").matchesJson("{\"friends\":[]}"); // lenient match with subset of fields
+		spec.path("me").matchesJson("{\"friends\":[]}"); // lenient match with subset of
+															// fields
 
 		assertThatThrownBy(() -> spec.path("me").matchesJsonStrictly("{\"friends\":[]}"))
-				.as("Extended fields should fail in strict mode")
-				.hasMessageContaining("Unexpected: name");
+				.as("Extended fields should fail in strict mode").hasMessageContaining("Unexpected: name");
 
-		setup.verifyRequest(input -> assertThat(input.getQuery()).contains(query));
+		setup.verifyRequest((input) -> assertThat(input.getQuery()).contains(query));
 		setup.shutdown();
 	}
 
@@ -126,22 +125,16 @@ public class GraphQlTesterTests {
 		MovieCharacter han = MovieCharacter.create("Han Solo");
 		AtomicReference<MovieCharacter> personRef = new AtomicReference<>();
 
-		MovieCharacter actual = spec.path("me").entity(MovieCharacter.class)
-				.isEqualTo(luke)
-				.isNotEqualTo(han)
-				.satisfies(personRef::set)
-				.matches(movieCharacter -> personRef.get().equals(movieCharacter))
-				.isSameAs(personRef.get())
-				.isNotSameAs(luke)
-				.get();
+		MovieCharacter actual = spec.path("me").entity(MovieCharacter.class).isEqualTo(luke).isNotEqualTo(han)
+				.satisfies(personRef::set).matches((movieCharacter) -> personRef.get().equals(movieCharacter))
+				.isSameAs(personRef.get()).isNotSameAs(luke).get();
 
 		assertThat(actual.getName()).isEqualTo("Luke Skywalker");
 
-		spec.path("")
-				.entity(new ParameterizedTypeReference<Map<String, MovieCharacter>>() {})
-				.isEqualTo(Collections.singletonMap("me", luke));
+		spec.path("").entity(new ParameterizedTypeReference<Map<String, MovieCharacter>>() {
+		}).isEqualTo(Collections.singletonMap("me", luke));
 
-		setup.verifyRequest(input -> assertThat(input.getQuery()).contains(query));
+		setup.verifyRequest((input) -> assertThat(input.getQuery()).contains(query));
 		setup.shutdown();
 	}
 
@@ -150,13 +143,8 @@ public class GraphQlTesterTests {
 	void entityList(GraphQlTesterSetup setup) throws Exception {
 
 		String query = "{me {name, friends}}";
-		setup.response("{" +
-				"  \"me\":{" +
-				"      \"name\":\"Luke Skywalker\"," +
-				"      \"friends\":[{\"name\":\"Han Solo\"}, {\"name\":\"Leia Organa\"}]" +
-				"  }" +
-				"}"
-				);
+		setup.response("{" + "  \"me\":{" + "      \"name\":\"Luke Skywalker\","
+				+ "      \"friends\":[{\"name\":\"Han Solo\"}, {\"name\":\"Leia Organa\"}]" + "  }" + "}");
 
 		GraphQlTester.ResponseSpec spec = setup.graphQlTester().query(query).execute();
 
@@ -164,22 +152,16 @@ public class GraphQlTesterTests {
 		MovieCharacter leia = MovieCharacter.create("Leia Organa");
 		MovieCharacter jabba = MovieCharacter.create("Jabba the Hutt");
 
-		List<MovieCharacter> actual = spec.path("me.friends").entityList(MovieCharacter.class)
-				.contains(han)
-				.containsExactly(han, leia)
-				.doesNotContain(jabba)
-				.hasSize(2)
-				.hasSizeGreaterThan(1)
-				.hasSizeLessThan(3)
+		List<MovieCharacter> actual = spec.path("me.friends").entityList(MovieCharacter.class).contains(han)
+				.containsExactly(han, leia).doesNotContain(jabba).hasSize(2).hasSizeGreaterThan(1).hasSizeLessThan(3)
 				.get();
 
 		assertThat(actual).containsExactly(han, leia);
 
-		spec.path("me.friends")
-				.entityList(new ParameterizedTypeReference<MovieCharacter>() {})
-				.containsExactly(han, leia);
+		spec.path("me.friends").entityList(new ParameterizedTypeReference<MovieCharacter>() {
+		}).containsExactly(han, leia);
 
-		setup.verifyRequest(input -> assertThat(input.getQuery()).contains(query));
+		setup.verifyRequest((input) -> assertThat(input.getQuery()).contains(query));
 		setup.shutdown();
 	}
 
@@ -187,23 +169,17 @@ public class GraphQlTesterTests {
 	@MethodSource("argumentSource")
 	void operationNameAndVariables(GraphQlTesterSetup setup) throws Exception {
 
-		String query = "query HeroNameAndFriends($episode: Episode) {" +
-				"  hero(episode: $episode) {" +
-				"    name" +
-				"  }" +
-				"}";
+		String query = "query HeroNameAndFriends($episode: Episode) {" + "  hero(episode: $episode) {" + "    name"
+				+ "  }" + "}";
 
 		setup.response("{\"hero\": {\"name\":\"R2-D2\"}}");
 
-		GraphQlTester.ResponseSpec spec = setup.graphQlTester().query(query)
-				.operationName("HeroNameAndFriends")
-				.variable("episode", "JEDI")
-				.variables(map -> map.put("foo", "bar"))
-				.execute();
+		GraphQlTester.ResponseSpec spec = setup.graphQlTester().query(query).operationName("HeroNameAndFriends")
+				.variable("episode", "JEDI").variables((map) -> map.put("foo", "bar")).execute();
 
 		spec.path("hero").entity(MovieCharacter.class).isEqualTo(MovieCharacter.create("R2-D2"));
 
-		setup.verifyRequest(input -> {
+		setup.verifyRequest((input) -> {
 			assertThat(input.getQuery()).contains(query);
 			assertThat(input.getOperationName()).isEqualTo("HeroNameAndFriends");
 			assertThat(input.getVariables()).hasSize(2);
@@ -223,7 +199,7 @@ public class GraphQlTesterTests {
 		assertThatThrownBy(() -> setup.graphQlTester().query(query).executeAndVerify())
 				.hasMessageContaining("Response has 1 unexpected error(s).");
 
-		setup.verifyRequest(input -> assertThat(input.getQuery()).contains(query));
+		setup.verifyRequest((input) -> assertThat(input.getQuery()).contains(query));
 		setup.shutdown();
 	}
 
@@ -237,7 +213,7 @@ public class GraphQlTesterTests {
 		assertThatThrownBy(() -> setup.graphQlTester().query(query).execute().path("me"))
 				.hasMessageContaining("Response has 1 unexpected error(s).");
 
-		setup.verifyRequest(input -> assertThat(input.getQuery()).contains(query));
+		setup.verifyRequest((input) -> assertThat(input.getQuery()).contains(query));
 		setup.shutdown();
 	}
 
@@ -246,18 +222,14 @@ public class GraphQlTesterTests {
 	void errorsPartiallyFiltered(GraphQlTesterSetup setup) throws Exception {
 
 		String query = "{me {name, friends}}";
-		setup.response(
-				GraphqlErrorBuilder.newError().message("some error").build(),
+		setup.response(GraphqlErrorBuilder.newError().message("some error").build(),
 				GraphqlErrorBuilder.newError().message("some other error").build());
 
-		assertThatThrownBy(() ->
-				setup.graphQlTester().query(query).execute()
-						.errors()
-						.filter(error -> error.getMessage().equals("some error"))
-						.verify())
-				.hasMessageContaining("Response has 1 unexpected error(s) of 2 total.");
+		assertThatThrownBy(() -> setup.graphQlTester().query(query).execute().errors()
+				.filter((error) -> error.getMessage().equals("some error")).verify())
+						.hasMessageContaining("Response has 1 unexpected error(s) of 2 total.");
 
-		setup.verifyRequest(input -> assertThat(input.getQuery()).contains(query));
+		setup.verifyRequest((input) -> assertThat(input.getQuery()).contains(query));
 		setup.shutdown();
 	}
 
@@ -266,17 +238,13 @@ public class GraphQlTesterTests {
 	void errorsFiltered(GraphQlTesterSetup setup) throws Exception {
 
 		String query = "{me {name, friends}}";
-		setup.response(
-				GraphqlErrorBuilder.newError().message("some error").build(),
+		setup.response(GraphqlErrorBuilder.newError().message("some error").build(),
 				GraphqlErrorBuilder.newError().message("some other error").build());
 
-		setup.graphQlTester().query(query).execute()
-				.errors()
-				.filter(error -> error.getMessage().startsWith("some "))
-				.verify()
-				.path("me").pathDoesNotExist();
+		setup.graphQlTester().query(query).execute().errors().filter((error) -> error.getMessage().startsWith("some "))
+				.verify().path("me").pathDoesNotExist();
 
-		setup.verifyRequest(input -> assertThat(input.getQuery()).contains(query));
+		setup.verifyRequest((input) -> assertThat(input.getQuery()).contains(query));
 		setup.shutdown();
 	}
 
@@ -285,26 +253,21 @@ public class GraphQlTesterTests {
 	void errorsConsumed(GraphQlTesterSetup setup) throws Exception {
 
 		String query = "{me {name, friends}}";
-		setup.response(GraphqlErrorBuilder.newError()
-				.message("Invalid query")
-				.location(new SourceLocation(1, 2))
-				.build());
+		setup.response(
+				GraphqlErrorBuilder.newError().message("Invalid query").location(new SourceLocation(1, 2)).build());
 
-		setup.graphQlTester().query(query).execute()
-				.errors().satisfy(errors -> {
-					assertThat(errors).hasSize(1);
-					assertThat(errors.get(0).getMessage()).isEqualTo("Invalid query");
-					assertThat(errors.get(0).getLocations()).hasSize(1);
-					assertThat(errors.get(0).getLocations().get(0).getLine()).isEqualTo(1);
-					assertThat(errors.get(0).getLocations().get(0).getColumn()).isEqualTo(2);
-				})
-				.path("me").pathDoesNotExist();
+		setup.graphQlTester().query(query).execute().errors().satisfy((errors) -> {
+			assertThat(errors).hasSize(1);
+			assertThat(errors.get(0).getMessage()).isEqualTo("Invalid query");
+			assertThat(errors.get(0).getLocations()).hasSize(1);
+			assertThat(errors.get(0).getLocations().get(0).getLine()).isEqualTo(1);
+			assertThat(errors.get(0).getLocations().get(0).getColumn()).isEqualTo(2);
+		}).path("me").pathDoesNotExist();
 
-		setup.verifyRequest(input -> assertThat(input.getQuery()).contains(query));
+		setup.verifyRequest((input) -> assertThat(input.getQuery()).contains(query));
 		setup.shutdown();
 	}
 
-
 	private interface GraphQlTesterSetup {
 
 		GraphQlTester graphQlTester();
@@ -327,7 +290,6 @@ public class GraphQlTesterTests {
 
 	}
 
-
 	private static class MockWebServerSetup implements GraphQlTesterSetup {
 
 		private final MockWebServer server;
@@ -356,12 +318,10 @@ public class GraphQlTesterTests {
 				sb.append("\"data\":").append(data);
 			}
 			if (!CollectionUtils.isEmpty(errors)) {
-				List<Map<String, Object>> errorSpecs = errors.stream()
-						.map(GraphQLError::toSpecification)
+				List<Map<String, Object>> errorSpecs = errors.stream().map(GraphQLError::toSpecification)
 						.collect(Collectors.toList());
 
-				sb.append(StringUtils.hasText(data) ? ", " : "")
-						.append("\"errors\":")
+				sb.append(StringUtils.hasText(data) ? ", " : "").append("\"errors\":")
 						.append(OBJECT_MAPPER.writeValueAsString(errorSpecs));
 			}
 			sb.append("}");
@@ -380,7 +340,8 @@ public class GraphQlTesterTests {
 			assertThat(request.getHeader(HttpHeaders.CONTENT_TYPE)).isEqualTo("application/json");
 
 			String content = request.getBody().readUtf8();
-			Map<String, Object> map = new ObjectMapper().readValue(content, new TypeReference<Map<String, Object>>() {});
+			Map<String, Object> map = new ObjectMapper().readValue(content, new TypeReference<Map<String, Object>>() {
+			});
 			WebInput webInput = new WebInput(request.getRequestUrl().uri(), new HttpHeaders(), map, null);
 
 			consumer.accept(webInput);
@@ -390,8 +351,8 @@ public class GraphQlTesterTests {
 		public void shutdown() throws Exception {
 			this.server.shutdown();
 		}
-	}
 
+	}
 
 	private static class MockWebGraphQlHandlerSetup implements GraphQlTesterSetup {
 
@@ -401,7 +362,7 @@ public class GraphQlTesterTests {
 
 		private final GraphQlTester graphQlTester;
 
-		public MockWebGraphQlHandlerSetup() {
+		MockWebGraphQlHandlerSetup() {
 			this.graphQlTester = GraphQlTester.create(this.handler);
 		}
 
@@ -414,14 +375,15 @@ public class GraphQlTesterTests {
 		public void response(@Nullable String data, List<GraphQLError> errors) throws Exception {
 			ExecutionResultImpl.Builder builder = new ExecutionResultImpl.Builder();
 			if (data != null) {
-				builder.data(OBJECT_MAPPER.readValue(data, new TypeReference<Map<String, Object>>() {}));
+				builder.data(OBJECT_MAPPER.readValue(data, new TypeReference<Map<String, Object>>() {
+				}));
 			}
 			if (!CollectionUtils.isEmpty(errors)) {
 				builder.addErrors(errors);
 			}
 			ExecutionResult result = builder.build();
 			WebOutput output = new WebOutput(mock(WebInput.class), result);
-			when(this.handler.handle(this.bodyCaptor.capture())).thenReturn(Mono.just(output));
+			given(this.handler.handle(this.bodyCaptor.capture())).willReturn(Mono.just(output));
 		}
 
 		@Override
@@ -429,6 +391,7 @@ public class GraphQlTesterTests {
 			WebInput webInput = this.bodyCaptor.getValue();
 			consumer.accept(webInput);
 		}
+
 	}
 
 }
diff --git a/spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/MovieCharacter.java b/spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/MovieCharacter.java
index 17114709..bad8b1ec 100644
--- a/spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/MovieCharacter.java
+++ b/spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/MovieCharacter.java
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.test.tester;
 
 import org.springframework.lang.Nullable;
@@ -46,11 +47,12 @@ public class MovieCharacter {
 			return false;
 		}
 		MovieCharacter movieCharacter = (MovieCharacter) other;
-		return (this.name != null ? this.name.equals(movieCharacter.name) : movieCharacter.name == null);
+		return (this.name != null) ? this.name.equals(movieCharacter.name) : movieCharacter.name == null;
 	}
 
 	@Override
 	public int hashCode() {
-		return (this.name != null ? this.name.hashCode() : 0);
+		return (this.name != null) ? this.name.hashCode() : 0;
 	}
+
 }