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How to use ErrorCollector class of org.junit.rules package

Best junit code snippet using org.junit.rules.ErrorCollector

Source:TestJUnitPredefinedRules.java

...7import java.io.IOException;8import java.util.concurrent.TimeUnit;9import org.junit.Rule;10import org.junit.Test;11import org.junit.rules.ErrorCollector;12import org.junit.rules.ExpectedException;13import org.junit.rules.TemporaryFolder;14import org.junit.rules.TestName;15import org.junit.rules.Timeout;16import org.junit.rules.Verifier;17/**18 * @author vivek19 *20 */21public class TestJUnitPredefinedRules {22	/**23	 * This rule helps get the name of currently executing test case.24	 */25	@Rule26	public TestName testName = new TestName();27	/**28	 * This rule helps in creating temporary folders and files.29	 */30	@Rule31	public TemporaryFolder temporaryFolder = new TemporaryFolder();32	/**33	 * This rule helps verify that particular test case throws an expected exception34	 * or not.35	 */36	@Rule37	public ExpectedException expectedException = ExpectedException.none();38	/**39	 * The Timeout Rule applies the same timeout to all test methods in a class.40	 */41	@Rule42	public Timeout timeout = new Timeout(5, TimeUnit.SECONDS);43	/**44	 * The ErrorCollector rule allows execution of a test to continue after the45	 * first problem is found.46	 */47	@Rule48	public ErrorCollector errorCollector = new ErrorCollector();49	/**50	 * Verifier is a base class for Rules like ErrorCollector, which can51	 * turn otherwise passing test methods into failing tests if a verification check52	 * is failed.53	 */54	@Rule55	public Verifier verifier = new Verifier() {56		@Override57		protected void verify() throws Throwable {58			System.out.println("Verifier#Verify : " + testName.getMethodName());59		};60	};61	/**62	 * This is implementation of ExternalResource rule.63	 */64	@Rule65	public DatabaseResoureRule databaseResource = new DatabaseResoureRule();66	67	@Test68	public void testPrintHelloWorld_positiveTest() throws IOException, InterruptedException {69		// TestName Rule70		System.out.println("Executing : " + testName.getMethodName());71		// TemporaryFolder Rule72		System.out.println("Temp Folder Path : " + temporaryFolder.getRoot().getPath());73		// Creates a new temporary file.74		temporaryFolder.newFile();75		temporaryFolder.newFile("temp_file_1.txt");76		// Creates a new folder.77		temporaryFolder.newFolder();78		// Creates folder hierarchy79		temporaryFolder.newFolder("x", "xy", "xyz");80		// Sleep current thread81		// TimeUnit.SECONDS.sleep(40);82	}83	@Test84	public void testPrintHelloWorld_negativeTest() {85		// TestName rule86		System.out.println("Executing : " + testName.getMethodName());87		// ExpectedException - expected exception check88		expectedException.expect(IllegalArgumentException.class);89		expectedException.expectCause(isA(NullPointerException.class));90		expectedException.expectMessage("Invalid Argument");91		throw new IllegalArgumentException("Invalid Argument, cannot be empty or null.", new NullPointerException());92	}93	/**94	 * Timeout rule tester.95	 * 96	 * @throws InterruptedException97	 */98	@Test99	public void testTimeOutRule() throws InterruptedException {100		// Sleep will cause this method to take more than 10 seconds and therefore it101		// will terminated by Timeout rule.102		TimeUnit.SECONDS.sleep(10);103	}104	/**105	 * Test the functionality of ErrorCollector rule.106	 */107	@Test108	public void testErrorCollectorRule() {109		// First error occurred, instead of throwing it add in error collector.110		errorCollector.addError(new IllegalArgumentException("Invalid argument, cannot be nullor empty."));111		// Another exception identified.112		errorCollector.addError(new AssertionError("X must be identical to Y."));113		// Another check114		errorCollector.checkThat("Something went wrong, failure.", containsString("success"));115		// and so on till end of method.116		// Errors will be printed once the method execution completes.117	}118	119}...

Source:RulesUnitTest.java

...10import org.junit.Ignore;11import org.junit.Rule;12import org.junit.Test;13import org.junit.rules.DisableOnDebug;14import org.junit.rules.ErrorCollector;15import org.junit.rules.ExpectedException;16import org.junit.rules.TemporaryFolder;17import org.junit.rules.TestName;18import org.junit.rules.Timeout;19import org.slf4j.Logger;20import org.slf4j.LoggerFactory;21public class RulesUnitTest {22    private static final Logger LOG = LoggerFactory.getLogger(RulesUnitTest.class);23    @Rule24    public TemporaryFolder tmpFolder = new TemporaryFolder();25    @Rule26    public final ExpectedException thrown = ExpectedException.none();27    @Rule28    public TestName name = new TestName();29    @Rule30    public Timeout globalTimeout = Timeout.seconds(10);31    @Rule32    public final ErrorCollector errorCollector = new ErrorCollector();33    34    @Rule35    public DisableOnDebug disableTimeout = new DisableOnDebug(Timeout.seconds(30));36    37    @Rule38    public TestMethodNameLogger testLogger = new TestMethodNameLogger();39    @Test40    public void givenTempFolderRule_whenNewFile_thenFileIsCreated() throws IOException {41        File testFile = tmpFolder.newFile("test-file.txt");42        assertTrue("The file should have been created: ", testFile.isFile());43        assertEquals("Temp folder and test file should match: ", tmpFolder.getRoot(), testFile.getParentFile());44    }45    @Test46    public void givenIllegalArgument_whenExceptionThrown_thenMessageAndCauseMatches() {...

Source:AbstractTestRuleAdapterTests.java

...14import org.junit.jupiter.migrationsupport.rules.adapter.AbstractTestRuleAdapter;15import org.junit.jupiter.migrationsupport.rules.member.TestRuleAnnotatedMember;16import org.junit.platform.commons.JUnitException;17import org.junit.platform.commons.util.PreconditionViolationException;18import org.junit.rules.ErrorCollector;19import org.junit.rules.TemporaryFolder;20import org.junit.rules.TestRule;21import org.junit.rules.Verifier;22/**23 * @since 5.024 */25public class AbstractTestRuleAdapterTests {26	@Test27	void constructionWithAssignableArgumentsIsSuccessful() {28		new TestableTestRuleAdapter(new SimpleRuleAnnotatedMember(new ErrorCollector()), Verifier.class);29	}30	@Test31	void constructionWithUnassignableArgumentsFails() {32		PreconditionViolationException exception = assertThrows(PreconditionViolationException.class,33			() -> new TestableTestRuleAdapter(new SimpleRuleAnnotatedMember(new TemporaryFolder()), Verifier.class));34		assertEquals(exception.getMessage(),35			"class org.junit.rules.Verifier is not assignable from class org.junit.rules.TemporaryFolder");36	}37	@Test38	void exceptionsDuringMethodLookupAreWrappedAndThrown() {39		AbstractTestRuleAdapter adapter = new AbstractTestRuleAdapter(40			new SimpleRuleAnnotatedMember(new ErrorCollector()), Verifier.class) {41			@Override42			public void before() {43				super.executeMethod("foo");44			}45		};46		JUnitException exception = assertThrows(JUnitException.class, adapter::before);47		assertEquals(exception.getMessage(), "Failed to find method foo() in class org.junit.rules.ErrorCollector");48	}49	private static class TestableTestRuleAdapter extends AbstractTestRuleAdapter {50		TestableTestRuleAdapter(TestRuleAnnotatedMember annotatedMember, Class<? extends TestRule> adapteeClass) {51			super(annotatedMember, adapteeClass);52		}53	}54	private static class SimpleRuleAnnotatedMember implements TestRuleAnnotatedMember {55		private final TestRule testRule;56		SimpleRuleAnnotatedMember(TestRule testRule) {57			this.testRule = testRule;58		}59		@Override60		public TestRule getTestRule() {61			return this.testRule;...

Source:RulesTest.java

1package junitparams;2import org.junit.Rule;3import org.junit.Test;4import org.junit.rules.ErrorCollector;5import org.junit.rules.ExpectedException;6import org.junit.rules.TemporaryFolder;7import org.junit.rules.TestName;8import org.junit.rules.TestRule;9import org.junit.rules.TestWatcher;10import org.junit.rules.Timeout;11import org.junit.runner.JUnitCore;12import org.junit.runner.Result;13import org.junit.runner.RunWith;14import static org.assertj.core.api.Assertions.*;15@RunWith(JUnitParamsRunner.class)16public class RulesTest {17    @Rule18    public TemporaryFolder folder = new TemporaryFolder();19    @Rule20    public ExpectedException exception = ExpectedException.none();21    @Rule22    public ErrorCollector errors = new ErrorCollector();23    @Rule24    public TestName testName = new TestName();25    @Rule26    public TestWatcher testWatcher = new TestWatcher() {27    };28    @Rule29    public Timeout timeout = new Timeout(0);30    @Test31    @Parameters("")32    public void shouldHandleRulesProperly(String n) {33        assertThat(testName.getMethodName()).isEqualTo("shouldHandleRulesProperly");34    }35    @Test36    public void shouldProvideHelpfulExceptionMessageWhenRuleIsUsedImproperly() {...

ErrorCollector

Using AI Code Generation

1import org.junit.Rule;2import org.junit.Test;3import org.junit.rules.ErrorCollector;4import static org.hamcrest.MatcherAssert.assertThat;5import static org.hamcrest.Matchers.*;6public class ErrorCollectorTest {7	public ErrorCollector collector = new ErrorCollector();8	public void test1() {9		collector.addError(new Throwable("This is an error"));10		collector.addError(new Throwable("This is another error"));11	}12	public void test2() {13		collector.addError(new Throwable("This is an error"));14		assertThat("This is a failure", 1, equalTo(2));15		collector.addError(new Throwable("This is another error"));16	}17	public void test3() {18		assertThat("This is a failure", 1, equalTo(2));19	}20}21	at org.junit.Assert.fail(Assert.java:88)22	at org.junit.Assert.failNotEquals(Assert.java:834)23	at org.junit.Assert.assertEquals(Assert.java:645)24	at org.junit.Assert.assertEquals(Assert.java:631)25	at org.junit.Assert$assertEquals$0.call(Unknown Source)26	at ErrorCollectorTest.test3(ErrorCollectorTest.groovy:32)27	at org.junit.Assert.assertEquals(Assert.java:115)28	at org.junit.Assert.assertEquals(Assert.java:144)29	at org.junit.Assert$assertEquals$0.call(Unknown Source)30	at ErrorCollectorTest.test2(ErrorCollectorTest.groovy:27)31	at org.junit.Assert.assertEquals(Assert.java:115)32	at org.junit.Assert.assertEquals(Assert.java:144)33	at org.junit.Assert$assertEquals$0.call(Unknown Source)34	at ErrorCollectorTest.test2(ErrorCollectorTest.groovy:27)35	at org.junit.Assert.fail(Assert.java:88)36	at org.junit.Assert.fail(Assert.java:97)37	at org.junit.rules.ErrorCollector.verify(ErrorCollector.java:73)38	at org.junit.rules.ErrorCollector.access$100(ErrorCollector.java:32)39	at org.junit.rules.ErrorCollector$1.evaluate(ErrorCollector.java:65)40	at org.junit.rules.RunRules.evaluate(RunRules.java:20)

ErrorCollector

Using AI Code Generation

1import org.junit.Rule;2import org.junit.Test;3import org.junit.rules.ErrorCollector;4public class JUnitErrorCollector {5    public ErrorCollector collector = new ErrorCollector();6    public void test() {7        collector.addError(new Throwable("First error"));8        collector.addError(new Throwable("Second error"));9    }10}11    at JUnitErrorCollector.test(JUnitErrorCollector.java:11)12    at JUnitErrorCollector.test(JUnitErrorCollector.java:12)13import org.junit.Rule;14import org.junit.Test;15import org.junit.rules.TestWatcher;16import org.junit.runner.Description;17public class JUnitTestWatcher {18    public TestWatcher watchman = new TestWatcher() {19        protected void starting(Description description) {20            System.out.println("Starting test: " + description.getMethodName());21        }22        protected void succeeded(Description description) {23            System.out.println("Test succeeded: " + description.getMethodName());24        }25        protected void failed(Throwable e, Description description) {26            System.out.println("Test failed: " + description.getMethodName());27        }28        protected void finished(Description description) {29            System.out.println("Test finished: " + description.getMethodName

ErrorCollector

Using AI Code Generation

1import org.junit.Rule;2import org.junit.Test;3import org.junit.rules.ErrorCollector;4public class ErrorCollectorDemo {5   public ErrorCollector collector = new ErrorCollector();6   public void test1() {7      collector.addError(new Throwable("Error 1"));8      System.out.println("This is test1");9      collector.addError(new Throwable("Error 2"));10      System.out.println("This is test1");11      collector.addError(new Throwable("Error 3"));12      System.out.println("This is test1");13   }14   public void test2() {15      System.out.println("This is test2");16   }17   public void test3() {18      System.out.println("This is test3");19   }20}21JUnit @Rule ExpectedException.none()

ErrorCollector

Using AI Code Generation

1import org.junit.rules.ErrorCollector;2import org.junit.Rule;3import org.junit.Test;4import org.junit.runner.JUnitCore;5import org.junit.runner.Result;6import org.junit.runner.notification.Failure;7import static org.hamcrest.Matchers.*;8import java.util.ArrayList;9import java.util.List;10public class ErrorCollectorTest {11    public ErrorCollector collector = new ErrorCollector();12    public void example() {13        List<Integer> list = new ArrayList<Integer>();14        collector.checkThat(list, empty());15        list.add(1);16        collector.checkThat(list, hasSize(1));17        collector.checkThat(list, hasItem(1));18        collector.checkThat(list, hasItem(2));19        collector.checkThat(list, hasItem(3));20    }21    public static void main(String[] args) {22        Result result = JUnitCore.runClasses(ErrorCollectorTest.class);23        for (Failure failure : result.getFailures()) {24            System.out.println(failure.toString());25        }26        System.out.println(result.wasSuccessful());27    }28}29import org.junit.rules.ErrorCollector;30import org.junit.Rule;31import org.junit.Test;32import org

ErrorCollector

Using AI Code Generation

1import org.junit.rules.ErrorCollector;2import org.junit.Rule;3import org.junit.Test;4import java.util.ArrayList;5import java.util.List;6import static org.hamcrest.CoreMatchers.is;7import static org.hamcrest.CoreMatchers.not;8public class ErrorCollectorTest {9public ErrorCollector collector = new ErrorCollector();10public void testErrorCollector() {11List<String> list = new ArrayList<String>();12collector.checkThat(list.isEmpty(), is(true));13collector.checkThat(list.size(), is(0));14collector.checkThat(list.size(), not(1));15}16}17at org.junit.Assert.assertEquals(Assert.java:115)18at org.junit.Assert.assertEquals(Assert.java:144)19at org.junit.rules.ErrorCollector$1.evaluate(ErrorCollector.java:68)20at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:298)21at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:292)22at java.util.concurrent.FutureTask.run(FutureTask.java:262)23at java.lang.Thread.run(Thread.java:744)24at org.junit.Assert.assertEquals(Assert.java:115)25at org.junit.Assert.assertEquals(Assert.java:144)26at org.junit.rules.ErrorCollector$1.evaluate(ErrorCollector.java:68)27at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:298)28at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:292)29at java.util.concurrent.FutureTask.run(FutureTask.java:262)30at java.lang.Thread.run(Thread.java:744)31import org.junit.rules.TemporaryFolder;32import org.junit.Rule;33import org.junit.Test;34import java.io.File;35public class TemporaryFolderTest {36public TemporaryFolder folder = new TemporaryFolder();37public void testUsingTempFolder() throws Exception {38File createdFolder = folder.newFolder("newfolder");39File createdFile = folder.newFile("myfile.txt");40}41}

ErrorCollector

Using AI Code Generation

1public class TestErrorCollector {2    public ErrorCollector collector = new ErrorCollector();3    public void test1(){4        try {5            Assert.assertEquals("Error", 1, 2);6        }catch(Throwable t){7            collector.addError(t);8        }9        try {10            Assert.assertEquals("Error", 1, 2);11        }catch(Throwable t){12            collector.addError(t);13        }14    }15}

ErrorCollector

Using AI Code Generation

1import org.junit.Rule;2import org.junit.Test;3import org.junit.rules.ErrorCollector;4import org.junit.runner.JUnitCore;5import org.junit.runner.Result;6import org.junit.runner.notification.Failure;7import static org.hamcrest.CoreMatchers.equalTo;8import static org.hamcrest.CoreMatchers.is;9public class ErrorCollectorTest {10    public ErrorCollector collector = new ErrorCollector();11    public void test1() {12        collector.checkThat(1, is(equalTo(2)));13        collector.checkThat(2, is(equalTo(3)));14        collector.checkThat(3, is(equalTo(4)));15    }16    public void test2() {17        collector.checkThat("a", is(equalTo("b")));18        collector.checkThat("b", is(equalTo("c")));19        collector.checkThat("c", is(equalTo("d")));20    }21    public static void main(String[] args) {22        Result result = JUnitCore.runClasses(ErrorCollectorTest.class);23        for (Failure failure : result.getFailures()) {24            System.out.println(failure.toString());25        }26        System.out.println("Result=="+result.wasSuccessful());27    }28}29at org.junit.Assert.assertEquals(Assert.java:115)30at org.junit.Assert.assertEquals(Assert.java:144)31at org.junit.Assert$assertEquals.call(Unknown Source)32at ErrorCollectorTest.test1(ErrorCollectorTest.groovy:12)33at org.junit.Assert.assertEquals(Assert.java:115)34at org.junit.Assert.assertEquals(Assert.java:144)35at org.junit.Assert$assertEquals.call(Unknown Source)36at ErrorCollectorTest.test2(ErrorCollectorTest.groovy:21)37checkSucceeds() method

Source: How make JUnit print assertion results

12/**3 *  Colors that can be used4 */5public enum Color6{7    /**8     * Red color9     */10    red,1112    /**13     * Blue color14     */15    blue1617}18

Source: Continuing test execution in junit4 even when one of the asserts fails

1/**2 *  Colors that can be used3 *  {@link #RED}4 *  {@link #BLUE}5 */6public enum Color {78    /**9     * Red color10     */11     RED,1213    /**14     * Blue color15     */16    BLUE17}18

Source:Continuing test execution in junit4 even when one of the asserts fails

/**
 *  Colors that can be used
 *  {@link #RED}
 *  {@link #BLUE}
 */
public enum Color {

    /**
     * Red color
     */
     RED,

    /**
     * Blue color
     */
    BLUE
}

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Importance of Unit testing - Learn why Unit testing is essential during the development phase to identify bugs and errors.
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Assertions in JUnit - Assertions are used to validate or test that the result of an action/functionality is the same as expected. Learn in detail what assertions are and how to use them while performing JUnit testing.
Parameterization in JUnit - Parameterized Test enables you to run the same automated test scripts with different variables. By collecting data on each method's test parameters, you can minimize time spent on writing tests. Learn how to use parameterization in JUnit.
Nested Tests In JUnit 5 - A nested class is a non-static class contained within another class in a hierarchical structure. It can share the state and setup of the outer class. Learn about nested annotations in JUnit 5 with examples.
Best practices for JUnit testing - Learn about the best practices, such as always testing key methods and classes, integrating JUnit tests with your build, and more to get the best possible results.
Advanced Use Cases for JUnit testing - Take a deep dive into the advanced use cases, such as how to run JUnit tests in Jupiter, how to use JUnit 5 Mockito for Unit testing, and more for JUnit testing.