Migrate TestNG assertions to AssertJ

Migrate all existing TestNG based assertions to AssertJ and add
Checkstyle rules to ensure they don't return.

See gh-23022

spring-test/src/test/java/org/springframework/test/context/cache/ClassLevelDirtiesContextTestNGTests.java

@@ -182,8 +182,7 @@ public class ClassLevelDirtiesContextTestNGTests {
 
 
 		protected void assertApplicationContextWasAutowired() {
-			org.testng.Assert.assertNotNull(this.applicationContext,
-				"The application context should have been autowired.");
+			assertThat(this.applicationContext).as("The application context should have been autowired.").isNotNull();
 		}
 	}
 

spring-test/src/test/java/org/springframework/test/context/testng/AnnotationConfigTestNGSpringContextTests.java

@@ -25,8 +25,7 @@ import org.springframework.test.context.ContextConfiguration;
 import org.springframework.tests.sample.beans.Employee;
 import org.springframework.tests.sample.beans.Pet;
 
-import static org.testng.Assert.assertEquals;
-import static org.testng.Assert.assertNotNull;
+import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * Integration tests that verify support for
@@ -50,11 +49,11 @@ public class AnnotationConfigTestNGSpringContextTests extends AbstractTestNGSpri
 
 	@Test
 	void autowiringFromConfigClass() {
-		assertNotNull(employee, "The employee should have been autowired.");
-		assertEquals(employee.getName(), "John Smith");
+		assertThat(employee).as("The employee should have been autowired.").isNotNull();
+		assertThat(employee.getName()).isEqualTo("John Smith");
 
-		assertNotNull(pet, "The pet should have been autowired.");
-		assertEquals(pet.getName(), "Fido");
+		assertThat(pet).as("The pet should have been autowired.").isNotNull();
+		assertThat(pet.getName()).isEqualTo("Fido");
 	}
 
 

spring-test/src/test/java/org/springframework/test/context/testng/AnnotationConfigTransactionalTestNGSpringContextTests.java

@@ -38,10 +38,9 @@ import org.springframework.transaction.PlatformTransactionManager;
 import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.springframework.test.transaction.TransactionAssert.assertThatTransaction;
 import static org.springframework.transaction.support.TransactionSynchronizationManager.isActualTransactionActive;
-import static org.testng.Assert.assertEquals;
-import static org.testng.Assert.assertNotNull;
 
 /**
  * Integration tests that verify support for
@@ -86,12 +85,13 @@ public class AnnotationConfigTransactionalTestNGSpringContextTests
 	}
 
 	private void assertNumRowsInPersonTable(int expectedNumRows, String testState) {
-		assertEquals(countRowsInTable("person"), expectedNumRows, "the number of rows in the person table ("
-				+ testState + ").");
+		assertThat(countRowsInTable("person"))
+			.as("the number of rows in the person table (" + testState + ").")
+			.isEqualTo(expectedNumRows);
 	}
 
-	private void assertAddPerson(final String name) {
-		assertEquals(createPerson(name), 1, "Adding '" + name + "'");
+	private void assertAddPerson(String name) {
+		assertThat(createPerson(name)).as("Adding '%s'", name).isEqualTo(1);
 	}
 
 	@BeforeClass
@@ -104,20 +104,20 @@ public class AnnotationConfigTransactionalTestNGSpringContextTests
 
 	@AfterClass
 	void afterClass() {
-		assertEquals(numSetUpCalls, NUM_TESTS, "number of calls to setUp().");
-		assertEquals(numSetUpCallsInTransaction, NUM_TX_TESTS, "number of calls to setUp() within a transaction.");
-		assertEquals(numTearDownCalls, NUM_TESTS, "number of calls to tearDown().");
-		assertEquals(numTearDownCallsInTransaction, NUM_TX_TESTS, "number of calls to tearDown() within a transaction.");
+		assertThat(numSetUpCalls).as("number of calls to setUp().").isEqualTo(NUM_TESTS);
+		assertThat(numSetUpCallsInTransaction).as("number of calls to setUp() within a transaction.").isEqualTo(NUM_TX_TESTS);
+		assertThat(numTearDownCalls).as("number of calls to tearDown().").isEqualTo(NUM_TESTS);
+		assertThat(numTearDownCallsInTransaction).as("number of calls to tearDown() within a transaction.").isEqualTo(NUM_TX_TESTS);
 	}
 
 	@Test
 	@Transactional(propagation = Propagation.NOT_SUPPORTED)
 	void autowiringFromConfigClass() {
-		assertNotNull(employee, "The employee should have been autowired.");
-		assertEquals(employee.getName(), "John Smith");
+		assertThat(employee).as("The employee should have been autowired.").isNotNull();
+		assertThat(employee.getName()).isEqualTo("John Smith");
 
-		assertNotNull(pet, "The pet should have been autowired.");
-		assertEquals(pet.getName(), "Fido");
+		assertThat(pet).as("The pet should have been autowired.").isNotNull();
+		assertThat(pet.getName()).isEqualTo("Fido");
 	}
 
 	@BeforeTransaction
@@ -154,7 +154,7 @@ public class AnnotationConfigTransactionalTestNGSpringContextTests
 
 	@AfterTransaction
 	void afterTransaction() {
-		assertEquals(deletePerson(YODA), 1, "Deleting yoda");
+		assertThat(deletePerson(YODA)).as("Deleting yoda").isEqualTo(1);
 		assertNumRowsInPersonTable(1, "after a transactional test method");
 	}
 

spring-test/src/test/java/org/springframework/test/context/testng/ConcreteTransactionalTestNGSpringContextTests.java

@@ -35,12 +35,9 @@ import org.springframework.tests.sample.beans.Pet;
 import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.springframework.test.transaction.TransactionAssert.assertThatTransaction;
 import static org.springframework.transaction.support.TransactionSynchronizationManager.isActualTransactionActive;
-import static org.testng.Assert.assertEquals;
-import static org.testng.Assert.assertNotNull;
-import static org.testng.Assert.assertNull;
-import static org.testng.Assert.assertTrue;
 
 /**
  * Combined integration test for {@link AbstractTestNGSpringContextTests} and
@@ -115,10 +112,10 @@ public class ConcreteTransactionalTestNGSpringContextTests extends AbstractTrans
 
 	@AfterClass
 	void afterClass() {
-		assertEquals(numSetUpCalls, NUM_TESTS, "number of calls to setUp().");
-		assertEquals(numSetUpCallsInTransaction, NUM_TX_TESTS, "number of calls to setUp() within a transaction.");
-		assertEquals(numTearDownCalls, NUM_TESTS, "number of calls to tearDown().");
-		assertEquals(numTearDownCallsInTransaction, NUM_TX_TESTS, "number of calls to tearDown() within a transaction.");
+		assertThat(numSetUpCalls).as("number of calls to setUp().").isEqualTo(NUM_TESTS);
+		assertThat(numSetUpCallsInTransaction).as("number of calls to setUp() within a transaction.").isEqualTo(NUM_TX_TESTS);
+		assertThat(numTearDownCalls).as("number of calls to tearDown().").isEqualTo(NUM_TESTS);
+		assertThat(numTearDownCallsInTransaction).as("number of calls to tearDown() within a transaction.").isEqualTo(NUM_TX_TESTS);
 	}
 
 	@BeforeMethod
@@ -147,7 +144,7 @@ public class ConcreteTransactionalTestNGSpringContextTests extends AbstractTrans
 
 	@AfterTransaction
 	void afterTransaction() {
-		assertEquals(deletePerson(YODA), 1, "Deleting yoda");
+		assertThat(deletePerson(YODA)).as("Deleting yoda").isEqualTo(1);
 		assertNumRowsInPersonTable(1, "after a transactional test method");
 	}
 
@@ -156,57 +153,60 @@ public class ConcreteTransactionalTestNGSpringContextTests extends AbstractTrans
 	@Transactional(propagation = Propagation.NOT_SUPPORTED)
 	void verifyBeanNameSet() {
 		assertThatTransaction().isNotActive();
-		assertTrue(this.beanName.startsWith(getClass().getName()), "The bean name of this test instance " +
-				"should have been set to the fully qualified class name due to BeanNameAware semantics.");
+		assertThat(this.beanName)
+			.as("The bean name of this test instance should have been set to the fully qualified class name due to BeanNameAware semantics.")
+			.startsWith(getClass().getName());
 	}
 
 	@Test
 	@Transactional(propagation = Propagation.NOT_SUPPORTED)
 	void verifyApplicationContextSet() {
 		assertThatTransaction().isNotActive();
-		assertNotNull(super.applicationContext,
-				"The application context should have been set due to ApplicationContextAware semantics.");
+		assertThat(super.applicationContext)
+			.as("The application context should have been set due to ApplicationContextAware semantics.")
+			.isNotNull();
 		Employee employeeBean = (Employee) super.applicationContext.getBean("employee");
-		assertEquals(employeeBean.getName(), "John Smith", "employee's name.");
+		assertThat(employeeBean.getName()).as("employee's name.").isEqualTo("John Smith");
 	}
 
 	@Test
 	@Transactional(propagation = Propagation.NOT_SUPPORTED)
 	void verifyBeanInitialized() {
 		assertThatTransaction().isNotActive();
-		assertTrue(beanInitialized,
-				"This test instance should have been initialized due to InitializingBean semantics.");
+		assertThat(beanInitialized)
+			.as("This test instance should have been initialized due to InitializingBean semantics.")
+			.isTrue();
 	}
 
 	@Test
 	@Transactional(propagation = Propagation.NOT_SUPPORTED)
 	void verifyAnnotationAutowiredFields() {
 		assertThatTransaction().isNotActive();
-		assertNull(nonrequiredLong, "The nonrequiredLong field should NOT have been autowired.");
-		assertNotNull(pet, "The pet field should have been autowired.");
-		assertEquals(pet.getName(), "Fido", "pet's name.");
+		assertThat(nonrequiredLong).as("The nonrequiredLong field should NOT have been autowired.").isNull();
+		assertThat(pet).as("The pet field should have been autowired.").isNotNull();
+		assertThat(pet.getName()).as("pet's name.").isEqualTo("Fido");
 	}
 
 	@Test
 	@Transactional(propagation = Propagation.NOT_SUPPORTED)
 	void verifyAnnotationAutowiredMethods() {
 		assertThatTransaction().isNotActive();
-		assertNotNull(employee, "The setEmployee() method should have been autowired.");
-		assertEquals(employee.getName(), "John Smith", "employee's name.");
+		assertThat(employee).as("The setEmployee() method should have been autowired.").isNotNull();
+		assertThat(employee.getName()).as("employee's name.").isEqualTo("John Smith");
 	}
 
 	@Test
 	@Transactional(propagation = Propagation.NOT_SUPPORTED)
 	void verifyResourceAnnotationInjectedFields() {
 		assertThatTransaction().isNotActive();
-		assertEquals(foo, "Foo", "The foo field should have been injected via @Resource.");
+		assertThat(foo).as("The foo field should have been injected via @Resource.").isEqualTo("Foo");
 	}
 
 	@Test
 	@Transactional(propagation = Propagation.NOT_SUPPORTED)
 	void verifyResourceAnnotationInjectedMethods() {
 		assertThatTransaction().isNotActive();
-		assertEquals(bar, "Bar", "The setBar() method should have been injected via @Resource.");
+		assertThat(bar).as("The setBar() method should have been injected via @Resource.").isEqualTo("Bar");
 	}
 
 	@Test
@@ -227,12 +227,13 @@ public class ConcreteTransactionalTestNGSpringContextTests extends AbstractTrans
 	}
 
 	private void assertNumRowsInPersonTable(int expectedNumRows, String testState) {
-		assertEquals(countRowsInTable("person"), expectedNumRows,
-				"the number of rows in the person table (" + testState + ").");
+		assertThat(countRowsInTable("person"))
+			.as("the number of rows in the person table (" + testState + ").")
+			.isEqualTo(expectedNumRows);
 	}
 
 	private void assertAddPerson(String name) {
-		assertEquals(createPerson(name), 1, "Adding '" + name + "'");
+		assertThat(createPerson(name)).as("Adding '" + name + "'").isEqualTo(1);
 	}
 
 }

spring-test/src/test/java/org/springframework/test/context/testng/DirtiesContextTransactionalTestNGSpringContextTests.java

@@ -23,10 +23,8 @@ import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.TestContextManager;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.springframework.test.transaction.TransactionAssert.assertThatTransaction;
-import static org.testng.Assert.assertNotNull;
-import static org.testng.Assert.assertNotSame;
-import static org.testng.Assert.assertSame;
 
 /**
  * <p>
@@ -56,10 +54,12 @@ public class DirtiesContextTransactionalTestNGSpringContextTests extends Abstrac
 
 	private void performCommonAssertions() {
 		assertThatTransaction().isActive();
-		assertNotNull(super.applicationContext,
-			"The application context should have been set due to ApplicationContextAware semantics.");
-		assertNotNull(super.jdbcTemplate,
-			"The JdbcTemplate should have been created in setDataSource() via DI for the DataSource.");
+		assertThat(super.applicationContext)
+			.as("The application context should have been set due to ApplicationContextAware semantics.")
+			.isNotNull();
+		assertThat(super.jdbcTemplate)
+			.as("The JdbcTemplate should have been created in setDataSource() via DI for the DataSource.")
+			.isNotNull();
 	}
 
 	@Test
@@ -72,15 +72,17 @@ public class DirtiesContextTransactionalTestNGSpringContextTests extends Abstrac
 	@Test(dependsOnMethods = { "dirtyContext" })
 	public void verifyContextWasDirtied() {
 		performCommonAssertions();
-		assertNotSame(super.applicationContext, this.dirtiedApplicationContext,
-			"The application context should have been 'dirtied'.");
+		assertThat(super.applicationContext)
+			.as("The application context should have been 'dirtied'.")
+			.isNotSameAs(this.dirtiedApplicationContext);
 		this.dirtiedApplicationContext = super.applicationContext;
 	}
 
 	@Test(dependsOnMethods = { "verifyContextWasDirtied" })
 	public void verifyContextWasNotDirtied() {
-		assertSame(this.applicationContext, this.dirtiedApplicationContext,
-			"The application context should NOT have been 'dirtied'.");
+		assertThat(this.applicationContext)
+			.as("The application context should NOT have been 'dirtied'.")
+			.isSameAs(this.dirtiedApplicationContext);
 	}
 
 }

spring-test/src/test/java/org/springframework/test/context/testng/transaction/ejb/AbstractEjbTxDaoTestNGTests.java

@@ -28,7 +28,7 @@ import org.springframework.test.annotation.DirtiesContext.ClassMode;
 import org.springframework.test.context.testng.AbstractTransactionalTestNGSpringContextTests;
 import org.springframework.test.context.transaction.ejb.dao.TestEntityDao;
 
-import static org.testng.AssertJUnit.assertEquals;
+import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * Abstract base class for all TestNG-based tests involving EJB transaction
@@ -53,13 +53,13 @@ public abstract class AbstractEjbTxDaoTestNGTests extends AbstractTransactionalT
 	@Test
 	public void test1InitialState() {
 		int count = dao.getCount(TEST_NAME);
-		assertEquals("New TestEntity should have count=0.", 0, count);
+		assertThat(count).as("New TestEntity should have count=0.").isEqualTo(0);
 	}
 
 	@Test(dependsOnMethods = "test1InitialState")
 	public void test2IncrementCount1() {
 		int count = dao.incrementCount(TEST_NAME);
-		assertEquals("Expected count=1 after first increment.", 1, count);
+		assertThat(count).as("Expected count=1 after first increment.").isEqualTo(1);
 	}
 
 	/**
@@ -70,10 +70,10 @@ public abstract class AbstractEjbTxDaoTestNGTests extends AbstractTransactionalT
 	@Test(dependsOnMethods = "test2IncrementCount1")
 	public void test3IncrementCount2() {
 		int count = dao.getCount(TEST_NAME);
-		assertEquals("Expected count=1 after test2IncrementCount1().", 1, count);
+		assertThat(count).as("Expected count=1 after test2IncrementCount1().").isEqualTo(1);
 
 		count = dao.incrementCount(TEST_NAME);
-		assertEquals("Expected count=2 now.", 2, count);
+		assertThat(count).as("Expected count=2 now.").isEqualTo(2);
 	}
 
 	@AfterMethod(alwaysRun = true)

spring-test/src/test/java/org/springframework/test/context/testng/transaction/ejb/RollbackForRequiredEjbTxDaoTestNGTests.java

@@ -21,7 +21,7 @@ import org.testng.annotations.Test;
 import org.springframework.test.annotation.Rollback;
 import org.springframework.test.context.transaction.TransactionalTestExecutionListener;
 
-import static org.testng.AssertJUnit.assertEquals;
+import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * Extension of {@link CommitForRequiredEjbTxDaoTestNGTests} which sets the default
@@ -52,10 +52,10 @@ public class RollbackForRequiredEjbTxDaoTestNGTests extends CommitForRequiredEjb
 		// participate in the existing transaction (if present), which in this case is the
 		// transaction managed by the TestContext framework which will be rolled back
 		// after each test method.
-		assertEquals("Expected count=0 after test2IncrementCount1().", 0, count);
+		assertThat(count).as("Expected count=0 after test2IncrementCount1().").isEqualTo(0);
 
 		count = dao.incrementCount(TEST_NAME);
-		assertEquals("Expected count=1 now.", 1, count);
+		assertThat(count).as("Expected count=1 now.").isEqualTo(1);
 	}
 
 }

spring-test/src/test/java/org/springframework/test/context/testng/web/ServletTestExecutionListenerTestNGIntegrationTests.java

@@ -72,7 +72,9 @@ public class ServletTestExecutionListenerTestNGIntegrationTests extends Abstract
 	}
 
 	private void assertInjectedServletRequestEqualsRequestInRequestContextHolder() {
-		assertThat(((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest()).as("Injected ServletRequest must be stored in the RequestContextHolder").isEqualTo(servletRequest);
+		assertThat(((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest())
+			.as("Injected ServletRequest must be stored in the RequestContextHolder")
+			.isEqualTo(servletRequest);
 	}
 
 }

spring-test/src/test/java/org/springframework/test/context/testng/web/TestNGSpringContextWebTests.java

@@ -100,14 +100,16 @@ public class TestNGSpringContextWebTests extends AbstractTestNGSpringContextTest
 		assertThat(webRequest).as("ServletWebRequest should have been autowired from the WAC.").isNotNull();
 
 		Object rootWac = mockServletContext.getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
-		assertThat(rootWac).as("Root WAC must be stored in the ServletContext as: "
-				+ WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE).isNotNull();
+		assertThat(rootWac)
+			.as("Root WAC must be stored in the ServletContext as: " + WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE)
+			.isNotNull();
 		assertThat(rootWac).as("test WAC and Root WAC in ServletContext must be the same object.").isSameAs(wac);
 		assertThat(wac.getServletContext()).as("ServletContext instances must be the same object.").isSameAs(mockServletContext);
 		assertThat(request.getServletContext()).as("ServletContext in the WAC and in the mock request").isSameAs(mockServletContext);
 
-		assertThat(mockServletContext.getRealPath("index.jsp")).as("Getting real path for ServletContext resource.").isEqualTo(new File("src/main/webapp/index.jsp").getCanonicalPath());
-
+		assertThat(mockServletContext.getRealPath("index.jsp"))
+			.as("Getting real path for ServletContext resource.")
+			.isEqualTo(new File("src/main/webapp/index.jsp").getCanonicalPath());
 	}
 
 	@Test

src/checkstyle/checkstyle.xml

@@ -98,7 +98,7 @@
 			<property name="id" value="bannedImports"/>
 			<property name="regexp" value="true" />
 			<property name="illegalClasses"
-				value="^reactor\.core\.support\.Assert,^junit\.framework\..+,^org\.junit\.Assert$,^org\.junit\.Assume$,^org\.junit\.jupiter\.api\.Assertions$,^org\.junit\.Assert\.assertThat,^org\.junit\.Assume\.assumeThat,^org\.junit\.rules\.ExpectedException,^org\.slf4j\.LoggerFactory" />
+				value="^reactor\.core\.support\.Assert,^junit\.framework\..+,^org\.junit\.Assert$,^org\.junit\.Assume$,^org\.junit\.jupiter\.api\.Assertions$,^org\.junit\.Assert\.assertThat,^org\.junit\.Assume\.assumeThat,^org\.testng\.Assert$,^org\.testng\.AssertJUnit$,^org\.junit\.rules\.ExpectedException,^org\.slf4j\.LoggerFactory" />
 		</module>
 		<module name="com.puppycrawl.tools.checkstyle.checks.imports.IllegalImportCheck">
 			<property name="id" value="bannedHamcrestImports"/>
@@ -194,6 +194,14 @@
 			<property name="message" value="Please use AssertJ assertions." />
 			<property name="ignoreComments" value="true" />
 		</module>
+		<module name="com.puppycrawl.tools.checkstyle.checks.regexp.RegexpSinglelineJavaCheck">
+			<property name="id" value="testNGAssertions"/>
+			<property name="maximum" value="0"/>
+			<!-- should cover org.testng.Assert and org.testng.AssertJUnit -->
+			<property name="format" value="org\.testng\.Assert(JUnit)?\.assert" />
+			<property name="message" value="Please use AssertJ assertions." />
+			<property name="ignoreComments" value="true" />
+		</module>
 
 		<!-- Spring Conventions -->
 		<module name="io.spring.javaformat.checkstyle.check.SpringLambdaCheck">