Simplify AssertJ usage

See gh-28862

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/cloudfoundry/servlet/CloudFoundryActuatorAutoConfigurationTests.java

@@ -233,7 +233,7 @@ class CloudFoundryActuatorAutoConfigurationTests {
 					ExposableWebEndpoint endpoint = endpoints.iterator().next();
 					assertThat(endpoint.getOperations()).hasSize(2);
 					WebOperation webOperation = findOperationWithRequestPath(endpoint, "health");
-					assertThat(webOperation).extracting("invoker").extracting("target")
+					assertThat(webOperation).extracting("invoker.target")
 							.isInstanceOf(CloudFoundryHealthEndpointWebExtension.class);
 				});
 	}

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/invoker/cache/CachingOperationInvokerTests.java

@@ -34,6 +34,7 @@ import org.springframework.boot.actuate.endpoint.OperationArgumentResolver;
 import org.springframework.boot.actuate.endpoint.SecurityContext;
 import org.springframework.boot.actuate.endpoint.invoke.OperationInvoker;
 
+import static org.assertj.core.api.Assertions.as;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
 import static org.mockito.BDDMockito.given;
@@ -115,8 +116,7 @@ class CachingOperationInvokerTests {
 			Thread.sleep(10);
 		}
 		invokeWithUniquePrincipal(invoker);
-		assertThat(invoker).extracting("cachedResponses").asInstanceOf(InstanceOfAssertFactories.MAP)
+		assertThat(invoker).extracting("cachedResponses", as(InstanceOfAssertFactories.MAP)).hasSizeLessThan(count);
-				.hasSizeLessThan(count);
 	}
 
 	private void invokeWithUniquePrincipal(CachingOperationInvoker invoker) {

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/web/reactive/client/MetricsWebClientCustomizerTests.java

@@ -58,7 +58,7 @@ class MetricsWebClientCustomizerTests {
 		this.clientBuilder.filters((filters) -> assertThat(filters).hasSize(1));
 		this.customizer.customize(this.clientBuilder);
 		this.clientBuilder.filters(
-				(filters) -> assertThat(filters).hasSize(1).first().isInstanceOf(MetricsWebClientFilterFunction.class));
+				(filters) -> assertThat(filters).singleElement().isInstanceOf(MetricsWebClientFilterFunction.class));
 	}
 
 }

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/couchbase/CouchbaseAutoConfigurationTests.java

@@ -39,6 +39,7 @@ import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
+import static org.assertj.core.api.Assertions.as;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.mock;
 
@@ -80,7 +81,7 @@ class CouchbaseAutoConfigurationTests {
 					expectedModuleIds.add(new JsonValueModule().getTypeId());
 					JsonSerializer serializer = env.jsonSerializer();
 					assertThat(serializer).extracting("wrapped").isInstanceOf(JacksonJsonSerializer.class)
-							.extracting("mapper").asInstanceOf(InstanceOfAssertFactories.type(ObjectMapper.class))
+							.extracting("mapper", as(InstanceOfAssertFactories.type(ObjectMapper.class)))
 							.extracting(ObjectMapper::getRegisteredModuleIds).isEqualTo(expectedModuleIds);
 				});
 	}

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/elasticsearch/ReactiveElasticsearchRestClientAutoConfigurationTests.java

@@ -276,8 +276,8 @@ class ReactiveElasticsearchRestClientAutoConfigurationTests {
 	void whenMaxInMemorySizeIsConfiguredThenUnderlyingWebClientHasCustomMaxInMemorySize(String prefix) {
 		this.contextRunner.withPropertyValues(prefix + "max-in-memory-size=1MB").run((context) -> {
 			WebClient client = configureWebClient(context.getBean(ClientConfiguration.class).getClientConfigurers());
-			assertThat(client).extracting("exchangeFunction").extracting("strategies").extracting("codecConfigurer")
+			assertThat(client).extracting("exchangeFunction.strategies.codecConfigurer.defaultCodecs")
-					.extracting("defaultCodecs").asInstanceOf(InstanceOfAssertFactories.type(DefaultCodecConfig.class))
+					.asInstanceOf(InstanceOfAssertFactories.type(DefaultCodecConfig.class))
 					.extracting(DefaultCodecConfig::maxInMemorySize).isEqualTo(1024 * 1024);
 		});
 	}

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/elasticsearch/ElasticsearchRestClientAutoConfigurationTests.java

@@ -161,8 +161,8 @@ class ElasticsearchRestClientAutoConfigurationTests {
 			RestClient client = context.getBean(RestHighLevelClient.class).getLowLevelClient();
 			assertThat(client.getNodes().stream().map(Node::getHost).map(HttpHost::toString))
 					.containsExactly("http://localhost:9200");
-			assertThat(client).extracting("client")
+			assertThat(client)
-					.extracting("credentialsProvider", InstanceOfAssertFactories.type(CredentialsProvider.class))
+					.extracting("client.credentialsProvider", InstanceOfAssertFactories.type(CredentialsProvider.class))
 					.satisfies((credentialsProvider) -> {
 						Credentials credentials = credentialsProvider.getCredentials(new AuthScope("localhost", 9200));
 						assertThat(credentials.getUserPrincipal().getName()).isEqualTo("user");
@@ -177,8 +177,8 @@ class ElasticsearchRestClientAutoConfigurationTests {
 			RestClient client = context.getBean(RestHighLevelClient.class).getLowLevelClient();
 			assertThat(client.getNodes().stream().map(Node::getHost).map(HttpHost::toString))
 					.containsExactly("http://localhost:9200");
-			assertThat(client).extracting("client")
+			assertThat(client)
-					.extracting("credentialsProvider", InstanceOfAssertFactories.type(CredentialsProvider.class))
+					.extracting("client.credentialsProvider", InstanceOfAssertFactories.type(CredentialsProvider.class))
 					.satisfies((credentialsProvider) -> {
 						Credentials credentials = credentialsProvider.getCredentials(new AuthScope("localhost", 9200));
 						assertThat(credentials.getUserPrincipal().getName()).isEqualTo("user");
@@ -194,8 +194,8 @@ class ElasticsearchRestClientAutoConfigurationTests {
 					RestClient client = context.getBean(RestHighLevelClient.class).getLowLevelClient();
 					assertThat(client.getNodes().stream().map(Node::getHost).map(HttpHost::toString))
 							.containsExactly("http://localhost:9200", "http://localhost:9201");
-					assertThat(client).extracting("client")
+					assertThat(client)
-							.extracting("credentialsProvider",
+							.extracting("client.credentialsProvider",
 									InstanceOfAssertFactories.type(CredentialsProvider.class))
 							.satisfies((credentialsProvider) -> {
 								Credentials uriCredentials = credentialsProvider

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/sendgrid/SendGridAutoConfigurationTests.java

@@ -74,8 +74,7 @@ class SendGridAutoConfigurationTests {
 		loadContext("spring.sendgrid.api-key:SG.SECRET-API-KEY", "spring.sendgrid.proxy.host:localhost",
 				"spring.sendgrid.proxy.port:5678");
 		SendGrid sendGrid = this.context.getBean(SendGrid.class);
-		assertThat(sendGrid).extracting("client").extracting("httpClient").extracting("routePlanner")
+		assertThat(sendGrid).extracting("client.httpClient.routePlanner").isInstanceOf(DefaultProxyRoutePlanner.class);
-				.isInstanceOf(DefaultProxyRoutePlanner.class);
 	}
 
 	private void loadContext(String... environment) {

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationJdbcTests.java

@@ -190,8 +190,7 @@ class SessionAutoConfigurationJdbcTests extends AbstractSessionAutoConfiguration
 					JdbcIndexedSessionRepository repository = validateSessionRepository(context,
 							JdbcIndexedSessionRepository.class);
 					DataSource sessionDataSource = context.getBean("sessionDataSource", DataSource.class);
-					assertThat(repository).extracting("jdbcOperations").extracting("dataSource")
+					assertThat(repository).extracting("jdbcOperations.dataSource").isEqualTo(sessionDataSource);
-							.isEqualTo(sessionDataSource);
 					assertThat(context.getBean(JdbcSessionDataSourceScriptDatabaseInitializer.class))
 							.hasFieldOrPropertyWithValue("dataSource", sessionDataSource);
 					assertThatExceptionOfType(BadSqlGrammarException.class).isThrownBy(

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationTests.java

@@ -160,7 +160,7 @@ class SessionAutoConfigurationTests extends AbstractSessionAutoConfigurationTest
 		this.contextRunner.withUserConfiguration(SessionRepositoryConfiguration.class)
 				.withPropertyValues("server.port=0").run((context) -> {
 					SessionRepositoryFilter<?> filter = context.getBean(SessionRepositoryFilter.class);
-					assertThat(filter).extracting("httpSessionIdResolver").extracting("cookieSerializer")
+					assertThat(filter).extracting("httpSessionIdResolver.cookieSerializer")
 							.isSameAs(context.getBean(DefaultCookieSerializer.class));
 				});
 	}

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/transaction/TransactionAutoConfigurationTests.java

@@ -131,7 +131,7 @@ class TransactionAutoConfigurationTests {
 		this.contextRunner.withUserConfiguration(SeveralPlatformTransactionManagersConfiguration.class)
 				.run((context) -> {
 					TransactionManagerCustomizers customizers = context.getBean(TransactionManagerCustomizers.class);
-					assertThat(customizers).extracting("customizers").asList().hasSize(1).first()
+					assertThat(customizers).extracting("customizers").asList().singleElement()
 							.isInstanceOf(TransactionProperties.class);
 				});
 	}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/builder/SpringApplicationBuilderTests.java

@@ -304,8 +304,7 @@ class SpringApplicationBuilderTests {
 			}
 		};
 		SpringApplication application = applicationBuilder.build();
-		assertThat(application).isInstanceOf(CustomSpringApplication.class)
+		assertThat(application).asInstanceOf(InstanceOfAssertFactories.type(CustomSpringApplication.class))
-				.asInstanceOf(InstanceOfAssertFactories.type(CustomSpringApplication.class))
 				.satisfies((customApp) -> assertThat(customApp.resourceLoader).isEqualTo(resourceLoader));
 	}
 

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/tomcat/TomcatReactiveWebServerFactoryTests.java

@@ -102,8 +102,7 @@ class TomcatReactiveWebServerFactoryTests extends AbstractReactiveWebServerFacto
 	void defaultTomcatListeners() {
 		TomcatReactiveWebServerFactory factory = getFactory();
 		if (AprLifecycleListener.isAprAvailable()) {
-			assertThat(factory.getContextLifecycleListeners()).hasSize(1).first()
+			assertThat(factory.getContextLifecycleListeners()).singleElement().isInstanceOf(AprLifecycleListener.class);
-					.isInstanceOf(AprLifecycleListener.class);
 		}
 		else {
 			assertThat(factory.getContextLifecycleListeners()).isEmpty();

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/tomcat/TomcatServletWebServerFactoryTests.java

@@ -135,8 +135,7 @@ class TomcatServletWebServerFactoryTests extends AbstractServletWebServerFactory
 	void defaultTomcatListeners() {
 		TomcatServletWebServerFactory factory = getFactory();
 		if (AprLifecycleListener.isAprAvailable()) {
-			assertThat(factory.getContextLifecycleListeners()).hasSize(1).first()
+			assertThat(factory.getContextLifecycleListeners()).singleElement().isInstanceOf(AprLifecycleListener.class);
-					.isInstanceOf(AprLifecycleListener.class);
 		}
 		else {
 			assertThat(factory.getContextLifecycleListeners()).isEmpty();