Migrate tests to AssertJ

Mostly thanks to IDEA's plugin: https://plugins.jetbrains.com/plugin/10345-assertions2assertj
There is still a lot of work to do when complex and composite matchers are used.

* Add `awaitility` dependency and deprecate `EventuallyMatcher` in favor
of `awaitility`
* Remove Hamcrest from dependencies and disable JUnit & Hamcrest
static imports to encourage to use only AssertJ
* Migrate JUnit assumptions in rules to AssertJ's assumptions
* Deprecate some custom matchers in favor of existing in Hamcrest
after upgrading the last to version `2.1`
* Replace `ExpectedException` rules with `assertThatThrownBy()`
* Mention `MessagePredicate` in the `testing.adoc`

Author: artembilan

build.gradle

@@ -92,6 +92,7 @@ subprojects { subproject ->
 		aspectjVersion = '1.9.2'
 		assertjVersion = '3.12.0'
 		assertkVersion = '0.13'
+		awaitilityVersion = '3.1.6'
 		boonVersion = '0.34'
 		commonsDbcp2Version = '2.5.0'
 		commonsIoVersion = '2.6'
@@ -102,7 +103,7 @@ subprojects { subproject ->
 		googleJsr305Version = '3.0.2'
 		groovyVersion = '2.5.6'
 		guavaVersion = '26.0-jre'
-		hamcrestVersion = '1.3'
+		hamcrestVersion = '2.1'
 		hazelcastVersion = '3.11.1'
 		hibernateVersion = '5.4.1.Final'
 		hsqldbVersion = '2.4.1'
@@ -159,12 +160,18 @@ subprojects { subproject ->
 	// dependencies that are common across all java projects
 	dependencies {
 		if (!(subproject.name ==~ /.*-test.*/)) {
-			testCompile project(":spring-integration-test-support")
+			testCompile (project(":spring-integration-test-support")) {
+				exclude group: 'org.hamcrest'
+			}
 		}
 
 		// JSR-305 only used for non-required meta-annotations
-		compileOnly("com.google.code.findbugs:jsr305:$googleJsr305Version")
-		testCompile("com.google.code.findbugs:jsr305:$googleJsr305Version")
+		compileOnly "com.google.code.findbugs:jsr305:$googleJsr305Version"
+		testCompile "com.google.code.findbugs:jsr305:$googleJsr305Version"
+
+		testCompile ("org.awaitility:awaitility:$awaitilityVersion") {
+			exclude group: 'org.hamcrest'
+		}
 
 		testCompile "org.junit.jupiter:junit-jupiter-api:$junitJupiterVersion"
 		testRuntime "org.junit.jupiter:junit-jupiter-engine:$junitJupiterVersion"
@@ -179,7 +186,7 @@ subprojects { subproject ->
 		testRuntime "org.apache.logging.log4j:log4j-slf4j-impl:$log4jVersion"
 		testRuntime "org.apache.logging.log4j:log4j-jcl:$log4jVersion"
 
-		testCompile("com.willowtreeapps.assertk:assertk-jvm:$assertkVersion")
+		testCompile "com.willowtreeapps.assertk:assertk-jvm:$assertkVersion"
 
 		testCompile "org.jetbrains.kotlin:kotlin-reflect"
 		testCompile "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
@@ -330,9 +337,10 @@ subprojects { subproject ->
 project('spring-integration-test-support') {
 	description = 'Spring Integration Test Support - **No SI Dependencies Allowed**'
 	dependencies {
-		compile "org.hamcrest:hamcrest-core:$hamcrestVersion"
 		compile "org.hamcrest:hamcrest-library:$hamcrestVersion"
-		compile "junit:junit:$junit4Version"
+		compile ("junit:junit:$junit4Version") {
+			exclude group: 'org.hamcrest'
+		}
 		compile ("org.junit.jupiter:junit-jupiter-api:$junitJupiterVersion", optional)
 		compileOnly 'org.apiguardian:apiguardian-api:1.0.0'
 		compile "org.mockito:mockito-core:$mockitoVersion"
@@ -459,6 +467,7 @@ project('spring-integration-http') {
 		compile ("com.rometools:rome:$romeToolsVersion", optional)
 
 		testCompile project(":spring-integration-security")
+		testCompile "org.hamcrest:hamcrest-core:$hamcrestVersion"
 		testCompile ("org.springframework.security:spring-security-config:$springSecurityVersion") {
 			exclude group: 'org.springframework'
 		}
@@ -674,7 +683,8 @@ project('spring-integration-webflux') {
 		}
 		compile "org.springframework:spring-webflux:$springVersion"
 		compile ("io.projectreactor.netty:reactor-netty:$reactorNettyVersion" , optional)
-
+		
+		testCompile "org.hamcrest:hamcrest-core:$hamcrestVersion"
 		testCompile "org.springframework:spring-webmvc:$springVersion"
 		testCompile ("org.springframework.security:spring-security-config:$springSecurityVersion") {
 			exclude group: 'org.springframework'

spring-integration-amqp/src/test/java/org/springframework/integration/amqp/channel/ChannelTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2018 the original author or authors.
+ * Copyright 2014-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +16,8 @@
 
 package org.springframework.integration.amqp.channel;
 
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.instanceOf;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertThat;
-import static org.junit.Assert.assertTrue;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.BDDMockito.willThrow;
 import static org.mockito.Mockito.mock;
@@ -34,9 +29,7 @@
 
 import org.junit.After;
 import org.junit.ClassRule;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 
 import org.springframework.amqp.core.AmqpTemplate;
@@ -80,9 +73,6 @@ public class ChannelTests {
 	public static final BrokerRunning brokerIsRunning =
 			BrokerRunning.isRunningWithEmptyQueues("pollableWithEP", "withEP", "testConvertFail");
 
-	@Rule
-	public ExpectedException exception = ExpectedException.none();
-
 	@Autowired
 	private PublishSubscribeAmqpChannel channel;
 
@@ -136,8 +126,8 @@ public void pubSubLostConnectionTest() throws Exception {
 		this.pubSubWithEP.destroy();
 		this.withEP.destroy();
 		this.pollableWithEP.destroy();
-		assertEquals(0,
-				TestUtils.getPropertyValue(connectionFactory, "connectionListener.delegates", Collection.class).size());
+		assertThat(TestUtils.getPropertyValue(connectionFactory, "connectionListener.delegates", Collection.class)
+				.size()).isEqualTo(0);
 	}
 
 	@SuppressWarnings("unchecked")
@@ -147,7 +137,8 @@ private void waitForNewConsumer(PublishSubscribeAmqpChannel channel, BlockingQue
 		final Object consumersMonitor = TestUtils.getPropertyValue(channel, "container.consumersMonitor");
 		int n = 0;
 		while (n++ < 100) {
-			Set<BlockingQueueConsumer> consumers = TestUtils.getPropertyValue(channel, "container.consumers", Set.class);
+			Set<BlockingQueueConsumer> consumers = TestUtils
+					.getPropertyValue(channel, "container.consumers", Set.class);
 			synchronized (consumersMonitor) {
 				if (!consumers.isEmpty()) {
 					BlockingQueueConsumer newConsumer = consumers.iterator().next();
@@ -158,7 +149,7 @@ private void waitForNewConsumer(PublishSubscribeAmqpChannel channel, BlockingQue
 			}
 			Thread.sleep(100);
 		}
-		assertTrue("Failed to restart consumer", n < 100);
+		assertThat(n < 100).as("Failed to restart consumer").isTrue();
 	}
 
 	/*
@@ -177,21 +168,21 @@ public void channelDeclarationTests() {
 		channel.afterPropertiesSet();
 		channel.onCreate(null);
 
-		assertNotNull(admin.getQueueProperties("implicit"));
+		assertThat(admin.getQueueProperties("implicit")).isNotNull();
 
 		admin.deleteQueue("explicit");
 		channel.setQueueName("explicit");
 		channel.afterPropertiesSet();
 		channel.onCreate(null);
 
-		assertNotNull(admin.getQueueProperties("explicit"));
+		assertThat(admin.getQueueProperties("explicit")).isNotNull();
 
 		admin.deleteQueue("explicit");
 		admin.declareQueue(new Queue("explicit", false)); // verify no declaration if exists with non-standard props
 		channel.afterPropertiesSet();
 		channel.onCreate(null);
 
-		assertNotNull(admin.getQueueProperties("explicit"));
+		assertThat(admin.getQueueProperties("explicit")).isNotNull();
 		admin.deleteQueue("explicit");
 	}
 
@@ -203,7 +194,7 @@ public void testAmqpChannelFactoryBean() throws Exception {
 		channelFactoryBean.setBeanName("testChannel");
 		channelFactoryBean.afterPropertiesSet();
 		AbstractAmqpChannel channel = channelFactoryBean.getObject();
-		assertThat(channel, instanceOf(PointToPointSubscribableAmqpChannel.class));
+		assertThat(channel).isInstanceOf(PointToPointSubscribableAmqpChannel.class);
 
 		channelFactoryBean = new AmqpChannelFactoryBean();
 		channelFactoryBean.setBeanFactory(mock(BeanFactory.class));
@@ -212,7 +203,7 @@ public void testAmqpChannelFactoryBean() throws Exception {
 		channelFactoryBean.setPubSub(true);
 		channelFactoryBean.afterPropertiesSet();
 		channel = channelFactoryBean.getObject();
-		assertThat(channel, instanceOf(PublishSubscribeAmqpChannel.class));
+		assertThat(channel).isInstanceOf(PublishSubscribeAmqpChannel.class);
 
 		RabbitAdmin rabbitAdmin = new RabbitAdmin(this.connectionFactory);
 		rabbitAdmin.deleteQueue("testChannel");
@@ -225,24 +216,24 @@ public void extractPayloadTests() {
 		Message<?> message = MessageBuilder.withPayload(foo).setHeader("baz", "qux").build();
 		this.pollableWithEP.send(message);
 		Message<?> received = this.pollableWithEP.receive(10000);
-		assertNotNull(received);
-		assertThat(received.getPayload(), equalTo(foo));
-		assertThat(received.getHeaders().get("baz"), equalTo("qux"));
+		assertThat(received).isNotNull();
+		assertThat(received.getPayload()).isEqualTo(foo);
+		assertThat(received.getHeaders().get("baz")).isEqualTo("qux");
 
 		this.withEP.send(message);
 		received = this.out.receive(10000);
-		assertNotNull(received);
-		assertThat(received.getPayload(), equalTo(foo));
-		assertThat(received.getHeaders().get("baz"), equalTo("qux"));
+		assertThat(received).isNotNull();
+		assertThat(received.getPayload()).isEqualTo(foo);
+		assertThat(received.getHeaders().get("baz")).isEqualTo("qux");
 
 		this.pubSubWithEP.send(message);
 		received = this.out.receive(10000);
-		assertNotNull(received);
-		assertThat(received.getPayload(), equalTo(foo));
-		assertThat(received.getHeaders().get("baz"), equalTo("qux"));
+		assertThat(received).isNotNull();
+		assertThat(received.getPayload()).isEqualTo(foo);
+		assertThat(received.getHeaders().get("baz")).isEqualTo("qux");
 
-		assertSame(this.mapperIn, TestUtils.getPropertyValue(this.pollableWithEP, "inboundHeaderMapper"));
-		assertSame(this.mapperOut, TestUtils.getPropertyValue(this.pollableWithEP, "outboundHeaderMapper"));
+		assertThat(TestUtils.getPropertyValue(this.pollableWithEP, "inboundHeaderMapper")).isSameAs(this.mapperIn);
+		assertThat(TestUtils.getPropertyValue(this.pollableWithEP, "outboundHeaderMapper")).isSameAs(this.mapperOut);
 	}
 
 	@Test
@@ -257,9 +248,9 @@ public void messageConversionTests() {
 				MessageListener.class);
 		willThrow(new MessageConversionException("foo", new IllegalStateException("bar")))
 				.given(messageConverter).fromMessage(any(org.springframework.amqp.core.Message.class));
-		this.exception.expect(MessageConversionException.class);
-		this.exception.expectCause(instanceOf(IllegalStateException.class));
-		listener.onMessage(mock(org.springframework.amqp.core.Message.class));
+		assertThatThrownBy(() -> listener.onMessage(mock(org.springframework.amqp.core.Message.class)))
+				.isInstanceOf(MessageConversionException.class)
+				.hasCauseInstanceOf(IllegalStateException.class);
 	}
 
 	public static class Foo {

spring-integration-amqp/src/test/java/org/springframework/integration/amqp/channel/DispatcherHasNoSubscribersTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,11 +16,8 @@
 
 package org.springframework.integration.amqp.channel;
 
-import static org.hamcrest.Matchers.containsString;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertThat;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.fail;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyString;
@@ -87,8 +84,8 @@ public void testPtP() throws Exception {
 			fail("Exception expected");
 		}
 		catch (MessageDeliveryException e) {
-			assertThat(e.getMessage(),
-					containsString("Dispatcher has no subscribers for amqp-channel 'noSubscribersChannel'."));
+			assertThat(e.getMessage())
+					.contains("Dispatcher has no subscribers for amqp-channel 'noSubscribersChannel'.");
 		}
 	}
 
@@ -135,19 +132,18 @@ private List<String> insertMockLoggerInListener(
 	}
 
 	private void verifyLogReceived(final List<String> logList) {
-		assertTrue("Failed to get expected exception", logList.size() > 0);
+		assertThat(logList.size() > 0).as("Failed to get expected exception").isTrue();
 		boolean expectedExceptionFound = false;
 		while (logList.size() > 0) {
 			String message = logList.remove(0);
-			assertNotNull("Failed to get expected exception", message);
+			assertThat(message).as("Failed to get expected exception").isNotNull();
 			if (message.startsWith("Dispatcher has no subscribers")) {
 				expectedExceptionFound = true;
-				assertThat(message,
-						containsString("Dispatcher has no subscribers for amqp-channel 'noSubscribersChannel'."));
+				assertThat(message).contains("Dispatcher has no subscribers for amqp-channel 'noSubscribersChannel'.");
 				break;
 			}
 		}
-		assertTrue("Failed to get expected exception", expectedExceptionFound);
+		assertThat(expectedExceptionFound).as("Failed to get expected exception").isTrue();
 	}
 
 }