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How to use handleAssertionErrors method of org.junit.rules.ExpectedException class

Best junit code snippet using org.junit.rules.ExpectedException.handleAssertionErrors

ExpectedException`org.junit.rules.ExpectedException`

The ExpectedException is a rule which helps scripts to verify that the script throws the specific exception or not

Code Snippets

Here are code snippets that can help you understand more how developers are using

Source:BddIntegrationTest.java

...13 * @author Lovro Pandzic14 */15public class BddIntegrationTest {16    @Rule17    public ExpectedException expectedException = ExpectedException.none().handleAssertionErrors();18    private ClassUnderTest classUnderTest = new ClassUnderTest();19    @Test20    public void shouldPassWhenExpectedExceptionIsThrown() throws Exception {21        when(() -> classUnderTest.throwsA(new Exception())).thenChecked(e -> assertThat(e, isA(Exception.class)));22    }23    @Test24    public void shouldFailWhenWrongExceptionIsThrown() throws Exception {25        expectedException.handleAssertionErrors();26        expectedException.expect(AssertionError.class);27        when(() -> classUnderTest.throwsA(new IOException())).then(e -> assertThat(e,28                                                                                   is(instanceOf(NullPointerException29                                                                                                         .class))));30    }31    @Test32    public void shouldPassWhenReturnsExpectedObject() {33        Object value = new Object();34        when(classUnderTest.returnsA(value)).then(actual -> assertThat(actual, is(equalTo(value))));35    }36    @Test37    public void simpleLambdaThrowTest() throws Exception {38        when(() -> {39            throw new Exception();40        }).thenChecked(e -> assertThat(e, isA(Exception.class)));41    }42    @Test43    public void simpleLambdaReturnTest() {44        when(new Object()).then(actual -> assertThat(actual, isA(Object.class)));45    }46    @Test(expected = Exception.class)47    public void shouldFailWhenValueProviderThrowsAUncheckedException() throws Exception {48        when(classUnderTest.throwsA(new Exception()));49    }50    @Test51    public void shouldFailWhenExceptionProviderThrowsAUncheckedException() throws Exception {52        expectedException.expect(isA(Exception.class));53        when(() -> classUnderTest.throwsA(new Exception())).thenShouldNotThrow();54    }55    @Test56    public void shouldFailWhenReturnsOneObjectButExpectsDifferentObject() {57        expectedException.handleAssertionErrors();58        expectedException.expect(AssertionError.class);59        expectedException.expectMessage("is <java.lang.Object");60        expectedException.expectMessage("but: was");61        Object value = new Object();62        when(classUnderTest.returnsA(value)).then(actual -> assertThat(actual, is(equalTo(new Object()))));63    }64    @Test65    public void shouldFailOnFirstWhenWhenTwoWhensFail() {66        expectedException.expect(isA(IOException.class));67        when(() -> classUnderTest.throwsA(new IOException()));68        when(() -> classUnderTest.throwsA(new Exception()));69    }70    @Test71    public void shouldFailWithUnexpectedExceptionForWrongCheckedException() {...

Source:ExpectedException.java

...15import org.junit.runners.model.Statement;16public class ExpectedException17implements TestRule {18    private final ExpectedExceptionMatcherBuilder fMatcherBuilder = new ExpectedExceptionMatcherBuilder();19    private boolean handleAssertionErrors = false;20    private boolean handleAssumptionViolatedExceptions = false;21    private ExpectedException() {22    }23    private void failDueToMissingException() throws AssertionError {24        String string2 = StringDescription.toString(this.fMatcherBuilder.build());25        Assert.fail("Expected test to throw " + string2);26    }27    private void handleException(Throwable throwable) throws Throwable {28        if (this.fMatcherBuilder.expectsThrowable()) {29            Assert.assertThat(throwable, this.fMatcherBuilder.build());30            return;31        }32        throw throwable;33    }34    public static ExpectedException none() {35        return new ExpectedException();36    }37    private void optionallyHandleException(Throwable throwable, boolean bl2) throws Throwable {38        if (bl2) {39            this.handleException(throwable);40            return;41        }42        throw throwable;43    }44    @Override45    public Statement apply(Statement statement, Description description) {46        return new ExpectedExceptionStatement(statement);47    }48    public void expect(Class<? extends Throwable> class_) {49        this.expect(CoreMatchers.instanceOf(class_));50    }51    public void expect(Matcher<?> matcher) {52        this.fMatcherBuilder.add(matcher);53    }54    public void expectCause(Matcher<? extends Throwable> matcher) {55        this.expect(ThrowableCauseMatcher.hasCause(matcher));56    }57    public void expectMessage(String string2) {58        this.expectMessage(CoreMatchers.containsString(string2));59    }60    public void expectMessage(Matcher<String> matcher) {61        this.expect(ThrowableMessageMatcher.hasMessage(matcher));62    }63    public ExpectedException handleAssertionErrors() {64        this.handleAssertionErrors = true;65        return this;66    }67    public ExpectedException handleAssumptionViolatedExceptions() {68        this.handleAssumptionViolatedExceptions = true;69        return this;70    }71    private class ExpectedExceptionStatement72    extends Statement {73        private final Statement fNext;74        public ExpectedExceptionStatement(Statement statement) {75            this.fNext = statement;76        }77        @Override78        public void evaluate() throws Throwable {79            try {80                this.fNext.evaluate();81                if (ExpectedException.this.fMatcherBuilder.expectsThrowable()) {82                    ExpectedException.this.failDueToMissingException();83                }84                return;85            }86            catch (AssumptionViolatedException var1_1) {87                ExpectedException.this.optionallyHandleException(var1_1, ExpectedException.this.handleAssumptionViolatedExceptions);88                return;89            }90            catch (AssertionError var1_2) {91                ExpectedException.this.optionallyHandleException((Throwable)((Object)var1_2), ExpectedException.this.handleAssertionErrors);92                return;93            }94            catch (Throwable var1_3) {95                ExpectedException.this.handleException(var1_3);96                return;97            }98        }99    }100}...

Source:ThreeTenBaseTest.java

...18public class ThreeTenBaseTest {19  @Rule20  public ExpectedException thrown = none();21  protected void expectException(Class<? extends Throwable> type, String message) {22    thrown.handleAssertionErrors();23    thrown.expect(type);24    thrown.expectMessage(message);25  }26  27  protected void expectIllegalArgumentException(String message) {28    expectException(IllegalArgumentException.class, message);29  }30  public void failBecauseExpectedAssertionErrorWasNotThrown() {31    Assert.fail("Assertion error expected");32  }33}...

handleAssertionErrors

Using AI Code Generation

1import org.junit.Rule;2import org.junit.Test;3import org.junit.rules.ExpectedException;4import static org.junit.Assert.assertEquals;5import static org.junit.Assert.fail;6public class TestJUnit4 {7    public ExpectedException thrown = ExpectedException.none();8    public void throwsNothing() {9    }10    public void throwsNullPointerException() {11        thrown.expect(NullPointerException.class);12        throw new NullPointerException();13    }14    public void throwsNullPointerExceptionWithMessage() {15        thrown.expect(NullPointerException.class);16        thrown.expectMessage("happened");17        thrown.reportMissingExceptionWithMessage("Expected NullPointerException to be thrown with message a string containing \"happened\"");18        throw new NullPointerException("something happened");19    }20    public void test() {21        try {22            throw new NullPointerException();23        } catch (NullPointerException e) {24            assertEquals("NullPointerException", e.getClass().getSimpleName());25        }26    }27    public void test2() {28        try {29            throw new NullPointerException();30        } catch (NullPointerException e) {31            assertEquals("NullPointerException", e.getClass().getSimpleName());32            return;33        }34        fail("Should have thrown an exception");35    }36}37The test() method is almost the same as the test2() method. The difference is that in the test() method, the catch

handleAssertionErrors

Using AI Code Generation

1import org.junit.Test;2import org.junit.Rule;3import org.junit.rules.ExpectedException;4public class TestException {5    public ExpectedException thrown = ExpectedException.none();6    public void throwsNothing() {7    }8    public void throwsNullPointerException() {9        thrown.expect(NullPointerException.class);10        throw new NullPointerException();11    }12    public void throwsIllegalArgumentException() {13        thrown.expect(IllegalArgumentException.class);14        throw new IllegalArgumentException();15    }16    public void throwsNullPointerExceptionWithMessage() {17        thrown.expect(NullPointerException.class);18        thrown.expectMessage("Hello");19        throw new NullPointerException("Hello");20    }21    public void throwsNullPointerExceptionWithMessageContaining() {22        thrown.expect(NullPointerException.class);23        thrown.expectMessage("Hello");24        throw new NullPointerException("Hello World");25    }26    public void throwsNullPointerExceptionWithMessageMatching() {27        thrown.expect(NullPointerException.class);28        thrown.expectMessage(".*H.llo.*");29        throw new NullPointerException("Hello World");30    }31    public void throwsNullPointerExceptionWithCause() {32        NullPointerException cause = new NullPointerException("Hello");33        thrown.expect(IllegalArgumentException.class);34        thrown.expectCause(is(cause));35        throw new IllegalArgumentException(cause);36    }37    public void throwsNullPointerExceptionWithCauseContaining() {38        NullPointerException cause = new NullPointerException("Hello");39        thrown.expect(IllegalArgumentException.class);40        thrown.expectCause(is(cause));41        throw new IllegalArgumentException(new NullPointerException("Hello World"));42    }43    public void throwsNullPointerExceptionWithCauseMatching() {44        NullPointerException cause = new NullPointerException("Hello");45        thrown.expect(IllegalArgumentException.class);46        thrown.expectCause(is(cause));47        throw new IllegalArgumentException(new NullPointerException("Hello World"));48    }49}

handleAssertionErrors

Using AI Code Generation

1import static org.junit.Assert.assertEquals;2import static org.junit.Assert.assertTrue;3import org.junit.Rule;4import org.junit.Test;5import org.junit.rules.ExpectedException;6public class ExpectedExceptionTest {7    public ExpectedException thrown = ExpectedException.none();8    public void throwsNothing() {9    }10    public void throwsNullPointerException() {11        thrown.expect(NullPointerException.class);12        throw new NullPointerException();13    }14    public void throwsNullPointerExceptionWithMessage() {15        thrown.expect(NullPointerException.class);16        thrown.expectMessage("happened");17        throw new NullPointerException("something happened");18    }19    public void throwsArithmeticExceptionWithMessage() {20        thrown.expect(ArithmeticException.class);21        thrown.expectMessage("/ by zero");22        int i = 1 / 0;23    }24    public void throwsArithmeticExceptionWithMessage2() {25        thrown.expect(ArithmeticException.class);26        thrown.expectMessage("/ by zero");27        thrown.expectMessage("second message");28        int i = 1 / 0;29    }30    public void throwsArithmeticExceptionWithMessage3() {31        thrown.expect(ArithmeticException.class);32        thrown.expectMessage("/ by zero");33        thrown.expectMessage("second message");34        int i = 1 / 0;35    }36    public void throwsArithmeticExceptionWithMessage4() {37        thrown.expect(ArithmeticException.class);38        thrown.expectMessage("/ by zero");39        thrown.expectMessage("second message");40        int i = 1 / 0;41    }42    public void throwsArithmeticExceptionWithMessage5() {43        thrown.expect(ArithmeticException.class);44        thrown.expectMessage("/ by zero");45        thrown.expectMessage("second message");46        int i = 1 / 0;47    }48    public void throwsArithmeticExceptionWithMessage6() {49        thrown.expect(ArithmeticException.class);50        thrown.expectMessage("/ by zero");51        thrown.expectMessage("second message");52        int i = 1 / 0;53    }54    public void throwsArithmeticExceptionWithMessage7() {55        thrown.expect(ArithmeticException.class);56        thrown.expectMessage("/ by zero");57        thrown.expectMessage("second message");

handleAssertionErrors

Using AI Code Generation

1[INFO] [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project junit4: Compilation failure: Compilation failure:2[INFO] [ERROR] symbol:   method handleAssertionErrors()3[INFO] [ERROR] symbol:   method handleAssertionErrors()4[INFO] [ERROR] symbol:   method handleAssertionErrors()5[INFO] [ERROR] symbol:   method handleAssertionErrors()6[INFO] [ERROR] symbol:   method handleAssertionErrors()7[INFO] [ERROR] symbol:   method handleAssertionErrors()

handleAssertionErrors

Using AI Code Generation

1import org.junit.Test;2import org.junit.rules.ExpectedException;3import static org.junit.Assert.assertEquals;4import static org.junit.Assert.fail;5public class ExceptionTest {6    public void testExceptionMessage() {7        try {8            throw new IllegalArgumentException("a message");9        } catch (IllegalArgumentException e) {10            assertEquals("a message", e.getMessage());11        }12    }13    public void testExceptionMessageWithRule() {14        ExpectedException thrown = ExpectedException.none();15        thrown.expect(IllegalArgumentException.class);16        thrown.expectMessage("a message");17        throw new IllegalArgumentException("a message");18    }19}20at org.junit.Assert.assertEquals(Assert.java:115)21at org.junit.Assert.assertEquals(Assert.java:144)22at com.baeldung.junit.exception.ExceptionTest.testExceptionMessage(ExceptionTest.java:11)23at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)24at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)25at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)26at java.lang.reflect.Method.invoke(Method.java:498)27at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)28at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)29at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)30at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)31at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)32at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)33at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)34at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)35at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)36at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)37at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)38at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)39at org.junit.runners.ParentRunner.run(ParentRunner.java:363)40at org.junit.runner.JUnitCore.run(JUnitCore.java:137)

handleAssertionErrors

Using AI Code Generation

1    public ExpectedException thrown = ExpectedException.none();2    public void testException() {3        thrown.expect(IllegalArgumentException.class);4        thrown.expectMessage("Negative value not allowed");5        MathUtils.divide(1, -1);6    }7    @Test(expected = IllegalArgumentException.class)8    public void testException2() {9        MathUtils.divide(1, -1);10    }11    public void testException3() {12        try {13            MathUtils.divide(1, -1);14            fail("Expected an IllegalArgumentException to be thrown");15        } catch (IllegalArgumentException anException) {16            assertThat(anException.getMessage(), is("Negative value not allowed"));17        }18    }19    public void testException4() {20        try {21            MathUtils.divide(1, 0);22            fail("Expected an ArithmeticException to be thrown");23        } catch (ArithmeticException anException) {24            assertThat(anException.getMessage(), is("Division by zero"));25        }26    }27}

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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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Features of JUnit - Learn about the numerous features of JUnit and why developers prefer it.
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Annotations in JUnit - When writing automation scripts with JUnit, we can use JUnit annotations to specify the type of methods in our test code. This helps us identify those methods when we run JUnit tests using Selenium WebDriver. Learn in detail what annotations are in JUnit.
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.