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

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

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

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Source:ExpectedExceptionCheckerTest.java

...23public class ExpectedExceptionCheckerTest {24  private final BugCheckerRefactoringTestHelper testHelper =25      BugCheckerRefactoringTestHelper.newInstance(ExpectedExceptionChecker.class, getClass());26  @Test27  public void expect() {28    testHelper29        .addInputLines(30            "in/ExceptionTest.java",31            "import static com.google.common.truth.Truth.assertThat;",32            "import java.io.IOException;",33            "import java.nio.file.*;",34            "import org.junit.Test;",35            "import org.junit.Rule;",36            "import org.hamcrest.CoreMatchers;",37            "import org.junit.rules.ExpectedException;",38            "class ExceptionTest {",39            "  @Rule ExpectedException thrown = ExpectedException.none();",40            "  @Test",41            "  public void test() throws Exception {",42            "    if (true) {",43            "      Path p = Paths.get(\"NOSUCH\");",44            "      thrown.expect(IOException.class);",45            "      thrown.expect(CoreMatchers.is(CoreMatchers.instanceOf(IOException.class)));",46            "      thrown.expectCause(",47            "          CoreMatchers.is(CoreMatchers.instanceOf(IOException.class)));",48            "      thrown.expectMessage(\"error\");",49            "      thrown.expectMessage(CoreMatchers.containsString(\"error\"));",50            "      Files.readAllBytes(p);",51            "      assertThat(Files.exists(p)).isFalse();",52            "    }",53            "  }",54            "}")55        .addOutputLines(56            "out/ExceptionTest.java",57            "import static com.google.common.truth.Truth.assertThat;",58            "import static org.hamcrest.MatcherAssert.assertThat;",59            "import static org.junit.Assert.assertThrows;",60            "",61            "import java.io.IOException;",62            "import java.nio.file.*;",63            "import org.hamcrest.CoreMatchers;",64            "import org.junit.Rule;",65            "import org.junit.Test;",66            "import org.junit.rules.ExpectedException;",67            "class ExceptionTest {",68            "  @Rule ExpectedException thrown = ExpectedException.none();",69            "  @Test",70            "  public void test() throws Exception {",71            "    if (true) {",72            "      Path p = Paths.get(\"NOSUCH\");",73            "      IOException thrown =",74            "          assertThrows(IOException.class, () -> Files.readAllBytes(p));",75            "      assertThat(thrown,",76            "          CoreMatchers.is(CoreMatchers.instanceOf(IOException.class)));",77            "      assertThat(thrown.getCause(),",78            "          CoreMatchers.is(CoreMatchers.instanceOf(IOException.class)));",79            "      assertThat(thrown).hasMessageThat().contains(\"error\");",80            "      assertThat(thrown.getMessage(), CoreMatchers.containsString(\"error\"));",81            "      assertThat(Files.exists(p)).isFalse();",82            "    }",83            "  }",84            "}")85        .doTest();86  }87  @Test88  public void noExceptionType() {89    testHelper90        .addInputLines(91            "in/ExceptionTest.java",92            "import static com.google.common.truth.Truth.assertThat;",93            "import java.io.IOException;",94            "import java.nio.file.*;",95            "import org.hamcrest.CoreMatchers;",96            "import org.junit.Rule;",97            "import org.junit.Test;",98            "import org.junit.rules.ExpectedException;",99            "class ExceptionTest {",100            "  @Rule ExpectedException thrown = ExpectedException.none();",101            "  @Test",102            "  public void test() throws Exception {",103            "    Path p = Paths.get(\"NOSUCH\");",104            "    thrown.expect(CoreMatchers.is(CoreMatchers.instanceOf(IOException.class)));",105            "    Files.readAllBytes(p);",106            "    Files.readAllBytes(p);",107            "  }",108            "}")109        .addOutputLines(110            "out/ExceptionTest.java",111            "import static com.google.common.truth.Truth.assertThat;",112            "import static org.hamcrest.MatcherAssert.assertThat;",113            "import static org.junit.Assert.assertThrows;",114            "",115            "import java.io.IOException;",116            "import java.nio.file.*;",117            "import org.hamcrest.CoreMatchers;",118            "import org.junit.Rule;",119            "import org.junit.Test;",120            "import org.junit.rules.ExpectedException;",121            "class ExceptionTest {",122            "  @Rule ExpectedException thrown = ExpectedException.none();",123            "  @Test",124            "  public void test() throws Exception {",125            "    Path p = Paths.get(\"NOSUCH\");",126            "    Throwable thrown = assertThrows(Throwable.class, () -> {",127            "      Files.readAllBytes(p);",128            "      Files.readAllBytes(p);",129            "    });",130            "    assertThat(thrown, CoreMatchers.is(CoreMatchers.instanceOf(IOException.class)));",131            "  }",132            "}")133        .doTest();134  }135  @Test136  public void noExpectations() {137    testHelper138        .addInputLines(139            "in/ExceptionTest.java",140            "import static com.google.common.truth.Truth.assertThat;",141            "import java.io.IOException;",142            "import java.nio.file.*;",143            "import org.hamcrest.CoreMatchers;",144            "import org.junit.Rule;",145            "import org.junit.Test;",146            "import org.junit.rules.ExpectedException;",147            "class ExceptionTest {",148            "  @Rule ExpectedException thrown = ExpectedException.none();",149            "  @Test",150            "  public void test() throws Exception {",151            "    Path p = Paths.get(\"NOSUCH\");",152            "    thrown.expect(IOException.class);",153            "    Files.readAllBytes(p);",154            "    assertThat(Files.exists(p)).isFalse();",155            "  }",156            "}")157        .addOutputLines(158            "out/ExceptionTest.java",159            "import static com.google.common.truth.Truth.assertThat;",160            "import static org.junit.Assert.assertThrows;",161            "import java.io.IOException;",162            "import java.nio.file.*;",163            "import org.hamcrest.CoreMatchers;",164            "import org.junit.Rule;",165            "import org.junit.Test;",166            "import org.junit.rules.ExpectedException;",167            "class ExceptionTest {",168            "  @Rule ExpectedException thrown = ExpectedException.none();",169            "  @Test",170            "  public void test() throws Exception {",171            "    Path p = Paths.get(\"NOSUCH\");",172            "    assertThrows(IOException.class, () -> Files.readAllBytes(p));",173            "    assertThat(Files.exists(p)).isFalse();",174            "  }",175            "}")176        .doTest();177  }178  @Test179  public void nonExpressionStatement() {180    testHelper181        .addInputLines(182            "in/ExceptionTest.java",183            "import static com.google.common.truth.Truth.assertThat;",184            "import java.io.IOException;",185            "import java.nio.file.*;",186            "import org.junit.Rule;",187            "import org.junit.Test;",188            "import org.junit.rules.ExpectedException;",189            "class ExceptionTest {",190            "  @Rule ExpectedException thrown = ExpectedException.none();",191            "  @Test",192            "  public void test() throws Exception {",193            "    Path p = Paths.get(\"NOSUCH\");",194            "    thrown.expect(IOException.class);",195            "    Files.readAllBytes(p);",196            "    if (true) Files.readAllBytes(p);",197            "  }",198            "}")199        .addOutputLines(200            "out/ExceptionTest.java",201            "import static com.google.common.truth.Truth.assertThat;",202            "import static org.junit.Assert.assertThrows;",203            "",204            "import java.io.IOException;",205            "import java.nio.file.*;",206            "import org.junit.Rule;",207            "import org.junit.Test;",208            "import org.junit.rules.ExpectedException;",209            "class ExceptionTest {",210            "  @Rule ExpectedException thrown = ExpectedException.none();",211            "  @Test",212            "  public void test() throws Exception {",213            "    Path p = Paths.get(\"NOSUCH\");",214            "    assertThrows(IOException.class, () -> {",215            "      Files.readAllBytes(p);",216            "      if (true) Files.readAllBytes(p);",217            "    });",218            "  }",219            "}")220        .doTest();221  }222  // https://github.com/hamcrest/JavaHamcrest/issues/27223  @Test224  public void isA_hasCauseThat() {225    testHelper226        .addInputLines(227            "in/ExceptionTest.java",228            "import static com.google.common.truth.Truth.assertThat;",229            "import java.io.IOException;",230            "import java.nio.file.*;",231            "import org.junit.Test;",232            "import org.junit.Rule;",233            "import org.hamcrest.CoreMatchers;",234            "import org.junit.rules.ExpectedException;",235            "class ExceptionTest {",236            "  @Rule ExpectedException thrown = ExpectedException.none();",237            "  @Test",238            "  public void test() throws Exception {",239            "    Path p = Paths.get(\"NOSUCH\");",240            "    thrown.expect(IOException.class);",241            "    thrown.expectCause(CoreMatchers.isA(IOException.class));",242            "    thrown.expectCause(org.hamcrest.core.Is.isA(IOException.class));",243            "    Files.readAllBytes(p);",244            "    assertThat(Files.exists(p)).isFalse();",245            "  }",246            "}")247        .addOutputLines(248            "out/ExceptionTest.java",249            "import static com.google.common.truth.Truth.assertThat;",250            "import static org.junit.Assert.assertThrows;",251            "",252            "import java.io.IOException;",253            "import java.nio.file.*;",254            "import org.hamcrest.CoreMatchers;",255            "import org.junit.Rule;",256            "import org.junit.Test;",257            "import org.junit.rules.ExpectedException;",258            "class ExceptionTest {",259            "  @Rule ExpectedException thrown = ExpectedException.none();",260            "  @Test",261            "  public void test() throws Exception {",262            "    Path p = Paths.get(\"NOSUCH\");",263            "    IOException thrown =",264            "        assertThrows(IOException.class, () -> Files.readAllBytes(p));",265            "    assertThat(thrown).hasCauseThat().isInstanceOf(IOException.class);",266            "    assertThat(thrown).hasCauseThat().isInstanceOf(IOException.class);",267            "    assertThat(Files.exists(p)).isFalse();",268            "  }",269            "}")270        .doTest();271  }272  @Test273  public void typedMatcher() {274    testHelper275        .addInputLines(276            "in/ExceptionTest.java",277            "import static com.google.common.truth.Truth.assertThat;",278            "import java.io.IOException;",279            "import java.nio.file.*;",280            "import org.junit.Test;",281            "import org.junit.Rule;",282            "import org.hamcrest.Matcher;",283            "import org.junit.rules.ExpectedException;",284            "class ExceptionTest {",285            "  @Rule ExpectedException thrown = ExpectedException.none();",286            "  Matcher<IOException> matcher;",287            "  @Test",288            "  public void test() throws Exception {",289            "    Path p = Paths.get(\"NOSUCH\");",290            "    thrown.expect(matcher);",291            "    Files.readAllBytes(p);",292            "    assertThat(Files.exists(p)).isFalse();",293            "  }",294            "}")295        .addOutputLines(296            "out/ExceptionTest.java",297            "import static com.google.common.truth.Truth.assertThat;",298            "import static org.hamcrest.MatcherAssert.assertThat;",299            "import static org.junit.Assert.assertThrows;",300            "",301            "import java.io.IOException;",302            "import java.nio.file.*;",303            "import org.hamcrest.Matcher;",304            "import org.junit.Rule;",305            "import org.junit.Test;",306            "import org.junit.rules.ExpectedException;",307            "class ExceptionTest {",308            "  @Rule ExpectedException thrown = ExpectedException.none();",309            "  Matcher<IOException> matcher;",310            "  @Test",311            "  public void test() throws Exception {",312            "    Path p = Paths.get(\"NOSUCH\");",313            "    IOException thrown =",314            "        assertThrows(IOException.class, () -> Files.readAllBytes(p));",315            "    assertThat(thrown, matcher);",316            "    assertThat(Files.exists(p)).isFalse();",317            "  }",318            "}")319        .doTest();320  }321  @Test322  public void nothingButAsserts() {323    testHelper324        .addInputLines(325            "in/ExceptionTest.java",326            "import static com.google.common.truth.Truth.assertThat;",327            "import org.junit.Rule;",328            "import org.junit.Test;",329            "import org.junit.rules.ExpectedException;",330            "class ExceptionTest {",331            "  @Rule ExpectedException thrown = ExpectedException.none();",332            "  @Test",333            "  public void test() throws Exception {",334            "    thrown.expect(RuntimeException.class);",335            "    assertThat(false).isFalse();",336            "    assertThat(true).isTrue();",337            "  }",338            "}")339        .addOutputLines(340            "out/ExceptionTest.java",341            "import static com.google.common.truth.Truth.assertThat;",342            "import org.junit.Rule;",343            "import org.junit.Test;",344            "import org.junit.rules.ExpectedException;",345            "class ExceptionTest {",346            "  @Rule ExpectedException thrown = ExpectedException.none();",347            "  @Test",348            "  public void test() throws Exception {",349            "    assertThat(false).isFalse();",350            "    assertThat(true).isTrue();",351            "  }",352            "}")353        .doTest();354  }355  @Test356  public void removeExplicitFail() {357    testHelper358        .addInputLines(359            "in/ExceptionTest.java",360            "import static com.google.common.truth.Truth.assertThat;",361            "import static org.junit.Assert.fail;",362            "import java.io.IOException;",363            "import java.nio.file.*;",364            "import org.junit.Test;",365            "import org.junit.Rule;",366            "import org.junit.rules.ExpectedException;",367            "class ExceptionTest {",368            "  @Rule ExpectedException thrown = ExpectedException.none();",369            "  @Test",370            "  public void testThrow() throws Exception {",371            "    thrown.expect(IOException.class);",372            "    throw new IOException();",373            "  }",374            "  @Test",375            "  public void one() throws Exception {",376            "    Path p = Paths.get(\"NOSUCH\");",377            "    thrown.expect(IOException.class);",378            "    Files.readAllBytes(p);",379            "    assertThat(Files.exists(p)).isFalse();",380            "    fail();",381            "  }",382            "  @Test",383            "  public void two() throws Exception {",384            "    Path p = Paths.get(\"NOSUCH\");",385            "    thrown.expect(IOException.class);",386            "    Files.readAllBytes(p);",387            "    assertThat(Files.exists(p)).isFalse();",388            "    throw new AssertionError();",389            "  }",390            "}")391        .addOutputLines(392            "out/ExceptionTest.java",393            "import static com.google.common.truth.Truth.assertThat;",394            "import static org.junit.Assert.assertThrows;",395            "import static org.junit.Assert.fail;",396            "",397            "import java.io.IOException;",398            "import java.nio.file.*;",399            "import org.junit.Rule;",400            "import org.junit.Test;",401            "import org.junit.rules.ExpectedException;",402            "class ExceptionTest {",403            "  @Rule ExpectedException thrown = ExpectedException.none();",404            "  @Test",405            "  public void testThrow() throws Exception {",406            "  }",407            "  @Test",408            "  public void one() throws Exception {",409            "    Path p = Paths.get(\"NOSUCH\");",410            "    assertThrows(IOException.class, () -> Files.readAllBytes(p));",411            "    assertThat(Files.exists(p)).isFalse();",412            "  }",413            "  @Test",414            "  public void two() throws Exception {",415            "    Path p = Paths.get(\"NOSUCH\");",416            "    assertThrows(IOException.class, () -> Files.readAllBytes(p));",417            "    assertThat(Files.exists(p)).isFalse();",418            "  }",419            "}")420        .doTest();421  }422  // https://github.com/google/error-prone/issues/1072423  @Test424  public void i1072() {425    testHelper426        .addInputLines(427            "in/ExceptionTest.java",428            "import org.junit.Rule;",429            "import org.junit.Test;",430            "import org.junit.rules.ExpectedException;",431            "class ExceptionTest {",432            "  @Rule ExpectedException thrown = ExpectedException.none();",433            "  @Test",434            "  public void testThrow(Class<? extends Throwable> clazz) throws Exception {",435            "    thrown.expect(clazz);",436            "    clazz.toString();",437            "  }",438            "}")439        .addOutputLines(440            "in/ExceptionTest.java",441            "import static org.junit.Assert.assertThrows;",442            "import org.junit.Rule;",443            "import org.junit.Test;",444            "import org.junit.rules.ExpectedException;",445            "class ExceptionTest {",446            "  @Rule ExpectedException thrown = ExpectedException.none();",447            "  @Test",448            "  public void testThrow(Class<? extends Throwable> clazz) throws Exception {",449            "    assertThrows(Throwable.class, () -> clazz.toString());",...

Source:ExpectedExceptionTest.java

...38                        ThrowExceptionWithWrongType.class,39                        hasSingleFailureWithMessage(startsWith("\nExpected: an instance of java.lang.NullPointerException"))},40                {41                        HasWrongMessage.class,42                        hasSingleFailureWithMessage(startsWith("\nExpected: exception with message a string containing \"expectedMessage\"\n"43                                + "     but: message was \"actualMessage\""))},44                {45                        ThrowNoExceptionButExpectExceptionWithType.class,46                        hasSingleFailureWithMessage("Expected test to throw an instance of java.lang.NullPointerException")},47                {WronglyExpectsExceptionMessage.class, hasSingleFailure()},48                {ExpectsSubstring.class, everyTestRunSuccessful()},49                {50                        ExpectsSubstringNullMessage.class,51                        hasSingleFailureWithMessage(startsWith("\nExpected: exception with message a string containing \"anything!\""))},52                {ExpectsMessageMatcher.class, everyTestRunSuccessful()},53                {54                        ExpectedMessageMatcherFails.class,55                        hasSingleFailureWithMessage(startsWith("\nExpected: exception with message \"Wrong start\""))},56                {ExpectsMatcher.class, everyTestRunSuccessful()},57                {ExpectAssertionErrorWhichIsNotThrown.class, hasSingleFailure()},58                {FailedAssumptionAndExpectException.class,59                        hasSingleAssumptionFailure()},60                {FailBeforeExpectingException.class,61                        hasSingleFailureWithMessage(ARBITRARY_MESSAGE)},62                {63                        ExpectsMultipleMatchers.class,64                        hasSingleFailureWithMessage(startsWith("\nExpected: (an instance of java.lang.IllegalArgumentException and exception with message a string containing \"Ack!\")"))},65                {ThrowExceptionWithMatchingCause.class, everyTestRunSuccessful()},66                {ThrowExpectedNullCause.class, everyTestRunSuccessful()},67                {68                        ThrowUnexpectedCause.class,69                        hasSingleFailureWithMessage(CoreMatchers.<String>allOf(70                                startsWith("\nExpected: ("),71                                containsString("exception with cause is <java.lang.NullPointerException: expected cause>"),72                                containsString("cause was <java.lang.NullPointerException: an unexpected cause>"),73                                containsString("Stacktrace was: java.lang.IllegalArgumentException: Ack!"),74                                containsString("Caused by: java.lang.NullPointerException: an unexpected cause")))},75                {76                        UseNoCustomMessage.class,77                        hasSingleFailureWithMessage("Expected test to throw an instance of java.lang.IllegalArgumentException") },78                {79                        UseCustomMessageWithoutPlaceHolder.class,80                        hasSingleFailureWithMessage(ARBITRARY_MESSAGE) },81                {82                        UseCustomMessageWithPlaceHolder.class,83                        hasSingleFailureWithMessage(ARBITRARY_MESSAGE84                                + " - an instance of java.lang.IllegalArgumentException") },85                {86                        ErrorCollectorShouldFailAlthoughExpectedExceptionDoesNot.class,87                        hasSingleFailureWithMessage(ARBITRARY_MESSAGE) }88        });89    }90    private final Class<?> classUnderTest;91    private final Matcher<EventCollector> matcher;92    public ExpectedExceptionTest(Class<?> classUnderTest,93            Matcher<EventCollector> matcher) {94        this.classUnderTest = classUnderTest;95        this.matcher = matcher;96    }97    @Test98    public void runTestAndVerifyResult() {99        EventCollector collector = new EventCollector();100        JUnitCore core = new JUnitCore();101        core.addListener(collector);102        core.run(classUnderTest);103        assertThat(collector, matcher);104    }105    public static class EmptyTestExpectingNoException {106        @Rule107        public ExpectedException thrown = none();108        @Test109        public void throwsNothing() {110        }111    }112    public static class ThrowExceptionWithExpectedType {113        @Rule114        public ExpectedException thrown = none();115        @Test116        public void throwsNullPointerException() {117            thrown.expect(NullPointerException.class);118            throw new NullPointerException();119        }120    }121    public static class ThrowExceptionWithExpectedPartOfMessage {122        @Rule123        public ExpectedException thrown = none();124        @Test125        public void throwsNullPointerExceptionWithMessage() {126            thrown.expect(NullPointerException.class);127            thrown.expectMessage(ARBITRARY_MESSAGE);128            throw new NullPointerException(ARBITRARY_MESSAGE + "something else");129        }130    }131    public static class ThrowExceptionWithWrongType {132        @Rule133        public ExpectedException thrown = none();134        @Test135        public void throwsNullPointerException() {136            thrown.expect(NullPointerException.class);137            throw new IllegalArgumentException();138        }139    }140    public static class HasWrongMessage {141        @Rule142        public ExpectedException thrown = none();143        @Test144        public void throwsNullPointerException() {145            thrown.expectMessage("expectedMessage");146            throw new IllegalArgumentException("actualMessage");147        }148    }149    public static class ThrowNoExceptionButExpectExceptionWithType {150        @Rule151        public ExpectedException thrown = none();152        @Test153        public void doesntThrowNullPointerException() {154            thrown.expect(NullPointerException.class);155        }156    }157    public static class WronglyExpectsExceptionMessage {158        @Rule159        public ExpectedException thrown = none();160        @Test161        public void doesntThrowAnything() {162            thrown.expectMessage("anything!");163        }164    }165    public static class ExpectsSubstring {166        @Rule167        public ExpectedException thrown = none();168        @Test169        public void throwsMore() {170            thrown.expectMessage("anything!");171            throw new NullPointerException(172                    "This could throw anything! (as long as it has the right substring)");173        }174    }175    public static class ExpectsSubstringNullMessage {176        @Rule177        public ExpectedException thrown = none();178        @Test179        public void throwsMore() {180            thrown.expectMessage("anything!");181            throw new NullPointerException();182        }183    }184    public static class ExpectsMessageMatcher {185        @Rule186        public ExpectedException thrown = none();187        @Test188        public void throwsMore() {189            thrown.expectMessage(startsWith(ARBITRARY_MESSAGE));190            throw new NullPointerException(ARBITRARY_MESSAGE + "!");191        }192    }193    public static class ExpectedMessageMatcherFails {194        @Rule195        public ExpectedException thrown = none();196        @Test197        public void throwsMore() {198            thrown.expectMessage(equalTo("Wrong start"));199            throw new NullPointerException("Back!");200        }201    }202    public static class ExpectsMatcher {203        @Rule204        public ExpectedException thrown = none();205        @Test206        public void throwsMore() {207            thrown.expect(any(Exception.class));208            throw new NullPointerException("Ack!");209        }210    }211    public static class ExpectsMultipleMatchers {212        @Rule213        public ExpectedException thrown = none();214        @Test215        public void throwsMore() {216            thrown.expect(IllegalArgumentException.class);217            thrown.expectMessage("Ack!");218            throw new NullPointerException("Ack!");219        }220    }221    //https://github.com/junit-team/junit4/pull/583222    public static class ExpectAssertionErrorWhichIsNotThrown {223        @Rule224        public ExpectedException thrown = none();225        @Test226        public void fails() {227            thrown.expect(AssertionError.class);228        }229    }230    public static class FailBeforeExpectingException {231        @Rule232        public ExpectedException thrown = none();233        @Test234        public void fails() {235            fail(ARBITRARY_MESSAGE);236            thrown.expect(IllegalArgumentException.class);237        }238    }239    public static class FailedAssumptionAndExpectException {240        @Rule241        public ExpectedException thrown = none();242        @Test243        public void failedAssumption() {244            assumeTrue(false);245            thrown.expect(NullPointerException.class);246        }247    }248    public static class ThrowExceptionWithMatchingCause {249        @Rule250        public ExpectedException thrown = none();251        @Test252        public void throwExceptionWithMatchingCause() {253            NullPointerException expectedCause = new NullPointerException("expected cause");254            thrown.expect(IllegalArgumentException.class);255            thrown.expectMessage("Ack!");256            thrown.expectCause(is(expectedCause));257            throw new IllegalArgumentException("Ack!", expectedCause);258        }259    }260    public static class ThrowExpectedNullCause {261        @Rule262        public ExpectedException thrown = none();263        @Test264        public void throwExpectedNullCause() {265            thrown.expect(IllegalArgumentException.class);266            thrown.expectMessage("Ack!");267            thrown.expectCause(nullValue(Throwable.class));268            throw new IllegalArgumentException("Ack!");269        }270    }271    public static class ThrowUnexpectedCause {272        @Rule273        public ExpectedException thrown = ExpectedException.none();274        @Test275        public void throwWithCause() {276            thrown.expect(IllegalArgumentException.class);277            thrown.expectMessage("Ack!");278            thrown.expectCause(is(new NullPointerException("expected cause")));279            throw new IllegalArgumentException("Ack!", new NullPointerException("an unexpected cause"));280        }281    }282    283    public static class UseNoCustomMessage {284        @Rule285        public ExpectedException thrown= ExpectedException.none();286        @Test287        public void noThrow() {288            thrown.expect(IllegalArgumentException.class);289        }290    }291    public static class UseCustomMessageWithPlaceHolder {292        @Rule293        public ExpectedException thrown = ExpectedException.none();294        @Test295        public void noThrow() {296            thrown.expect(IllegalArgumentException.class);297            thrown.reportMissingExceptionWithMessage(ARBITRARY_MESSAGE298                    + " - %s");299        }300    }301    public static class UseCustomMessageWithoutPlaceHolder {302        @Rule303        public ExpectedException thrown= ExpectedException.none();304        @Test305        public void noThrow() {306            thrown.expect(IllegalArgumentException.class);307            thrown.reportMissingExceptionWithMessage(ARBITRARY_MESSAGE);308        }309    }310    public static class ErrorCollectorShouldFailAlthoughExpectedExceptionDoesNot {311        @Rule312        public ErrorCollector collector = new ErrorCollector();313        @Rule(order = Integer.MAX_VALUE)314        public ExpectedException thrown = ExpectedException.none();315        @Test316        public void test() {317            collector.addError(new AssertionError(ARBITRARY_MESSAGE));318            thrown.expect(Exception.class);319            throw new RuntimeException();320        }321    }322}...

Source:JunitRuleTest.java

...43    @Rule44    public MethodLoggingRule methodLogger = new MethodLoggingRule();45    // ExpectedExceptionå¯ä»¥å¹éå¼å¸¸ç±»ååå¼å¸¸message46    @Rule47    public ExpectedException expectedException = ExpectedException.none();48    @Rule49    public RuleChain ruleChain = RuleChain.outerRule(new LoggingRule(3)).around(new LoggingRule(2)).around(new LoggingRule(1));50    @Test51    public void testTemporaryFolder() throws Exception {52        File file = temporaryFolder.newFile();53        log.info("file: {}", file.getAbsolutePath());54        FileUtils.writeStringToFile(file, "abc", "utf-8", true);55        log.info("read data: {}", FileUtils.readFileToString(file, "utf-8"));56        TimeUnit.SECONDS.sleep(10);57    }58    @Test59    public void testTimeout() throws InterruptedException {60        TimeUnit.SECONDS.sleep(20);61    }62    @Test63    public void testNotTimeout() throws InterruptedException {64        TimeUnit.SECONDS.sleep(1);65    }66    @Test67    public void testMethodLogRule() throws InterruptedException {68        TimeUnit.MILLISECONDS.sleep(1234);69    }70    @Test71    public void testExpectException1() {72        expectedException.expect(NumberFormatException.class);73        expectedException.expectMessage("For input string: \"a\"");74        Integer.parseInt("a");75    }76    @Test(expected = ArithmeticException.class)77    public void testExpectException2() {78        int n = 1 / 0;79    }80    @Test81    public void testRuleChain() {82    }83    @Slf4j84    private static class MethodLoggingRule implements MethodRule {85        @Override86        public Statement apply(Statement base, FrameworkMethod method, Object target) {87            String flag = target.getClass().getSimpleName() + "." + method.getName();88            return new Statement() {89                @Override90                public void evaluate() throws Throwable {...

Source:ExpectedException.java

...25import org.junit.runners.model.Statement;26import static org.hamcrest.CoreMatchers.equalTo;27/**28 * A custom variant of {@link org.junit.rules.ExpectedException} that verifies that the whole exception message29 * is identical to the expected message instead of just if the message contains the expected message.30 *31 * @author Christian Ihle32 */33public class ExpectedException implements TestRule {34    private final org.junit.rules.ExpectedException expectedException = org.junit.rules.ExpectedException.none();35    public static ExpectedException none() {36        return new ExpectedException();37    }38    @Override39    public Statement apply(final Statement base, final Description description) {40        return expectedException.apply(base, description);41    }42    /**43     * Which exception to expect.44     */45    public void expect(final Class<? extends Throwable> expectedExceptionClass) {46        expectedException.expect(expectedExceptionClass);47    }48    /**49     * The exact exception message to expect.50     */51    public void expectMessage(@NonNls final String expectedExceptionMessage) {52        expectedException.expectMessage(equalTo(expectedExceptionMessage));53    }54    /**55     * A part of the exception message to expect.56     */57    public void expectMessageContaining(@NonNls final String substring) {58        expectedException.expectMessage(substring);59    }60}...

Source:RuleTester.java

...17 * @date 2022/2/2018 */19public class RuleTester {20    @Rule21    public ExpectedException expectedException = ExpectedException.none();22    @Rule23    public TemporaryFolder folder = new TemporaryFolder();24    private Calculator calculator = new Calculator();25    private static File createdFolder;26    private static File createdFile;27    @Test28    public void expectIllegalArgumentException() {29        expectedException.expect(IllegalArgumentException.class);30        expectedException.expectMessage("Cannot extract the square root of a negative value");31        calculator.sqrt(-1);32    }33    @Test34    public void expectArithmeticException() {35        expectedException.expect(ArithmeticException.class);36        expectedException.expectMessage("Cannot divide by zero");37        calculator.divide(1, 0);38    }39    @Test40    public void testTemporaryFolder() throws IOException {41        createdFolder = folder.newFolder("createdFolder");42        createdFile = folder.newFile("createdFile.txt");43        assertTrue(createdFolder.exists());44        assertTrue(createdFile.exists());45    }46    @AfterClass47    public static void cleanUpAfterAllTestsRan() {48        assertFalse(createdFolder.exists());49        assertFalse(createdFile.exists());50    }...

Source:JUnit4BuiltInTestRulesTest.java

...14import org.junit.rules.TemporaryFolder;1516public class JUnit4BuiltInTestRulesTest {17    /*18     * you can use this template to create expected exceptions rules fast:19     * ${staticImp:importStatic(org.junit.rules.ExpectedException.none)}20     * ${imp:import(org.junit.Rule,org.junit.rules.ExpectedException)}@Rule21     * public ExpectedException exception = none();22     */2324    @Rule25    public ExpectedException exception = none();2627    @Rule28    public TemporaryFolder folder = new TemporaryFolder(); // can be called with29							   // parent folder3031    @Test32    public void comparingToExpectedInTestAnnotationWeCanValidateCauseAndMessageToo() throws Exception {33	exception.expect(RuntimeException.class);34	exception.expectCause(isA(IOException.class));35	exception.expectMessage("substring");3637	throw new IllegalArgumentException("Message containing substring", new IOException("the cause"));38    }3940    @Test41    public void youCanUseTemporaryFoldersThatAreRemovedAfterTheTests() throws Exception {42	File root = folder.getRoot();43	assertThat(root.exists(), is(true));4445	File anyTemporaryFile = folder.newFile();46	assertThat(anyTemporaryFile.exists(), is(true));47    }48}

Source:ExpectedLogMessagesRuleTest.java

...9/** Tests for {@link ExpectedLogMessagesRule}. */10@RunWith(AndroidJUnit4.class)11public final class ExpectedLogMessagesRuleTest {12  private ExpectedLogMessagesRule rule = new ExpectedLogMessagesRule();13  private ExpectedException expectedException = ExpectedException.none();14  @Rule public RuleChain chain = RuleChain.outerRule(expectedException).around(rule);15  @Test16  public void testAndroidExpectedLogMessagesFailsWithMessage() throws Exception {17    expectedException.expect(AssertionError.class);18    Log.e("Mytag", "What's up");19  }20  @Test21  public void testAndroidExpectedLogMessagesDoesNotFailWithExpected() throws Exception {22    rule.expectErrorsForTag("Mytag");23    Log.e("Mytag", "What's up");24  }25  @Test26  public void testNoExpectedMessageFailsTest() throws Exception {27    expectedException.expect(AssertionError.class);28    rule.expectLogMessage(Log.ERROR, "Mytag", "What's up");29  }30  @Test31  public void testNoExpectedTagFailsTest() throws Exception {32    expectedException.expect(AssertionError.class);33    rule.expectErrorsForTag("Mytag");34  }35}...

Source:RepeatUntilExpectedExceptionRule.java

...5import org.junit.runner.Description;6import org.junit.runners.model.Statement;7import static com.bluecatcode.junit.rules.RepeatRule.RepeatStatement.createFromAnnotationWith;8public class RepeatUntilExpectedExceptionRule implements TestRule {9    private ExpectedException expectedException = ExpectedException.none();10    @Override11    public Statement apply(Statement statement, Description description) {12        Repeat repeat = description.getAnnotation(Repeat.class);13        Statement statement1 = createFromAnnotationWith(repeat, statement);14        Statement resultStatement = statement1 == null ? statement : statement1;15        return expectedException.apply(resultStatement, description);16    }17    public void expectMessage(Matcher<String> matcher) {18        expectedException.expectMessage(matcher);19    }20    public void expect(Class<? extends Throwable> type) {21        expectedException.expect(type);22    }23    public void expect(Matcher<?> matcher) {24        expectedException.expect(matcher);25    }26    public void expectMessage(String substring) {27        expectedException.expectMessage(substring);28    }29}...

expect

Using AI Code Generation

1import org.junit.Rule;2import org.junit.Test;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 throwsNullPointerExceptionWithMessage() {13        thrown.expect(NullPointerException.class);14        thrown.expectMessage("Hello");15        throw new NullPointerException("Hello");16    }17    public void throwsNullPointerExceptionWithMessageContaining() {18        thrown.expect(NullPointerException.class);19        thrown.expectMessage("Hello");20        throw new NullPointerException("Hello World");21    }22}23    at org.junit.Assert.assertEquals(Assert.java:115)24    at org.junit.Assert.assertEquals(Assert.java:144)25    at org.junit.rules.ExpectedException.handleException(ExpectedException.java:239)26    at org.junit.rules.ExpectedException.access$000(ExpectedException.java:67)27    at org.junit.rules.ExpectedException$ExpectedExceptionStatement.evaluate(ExpectedException.java:231)28    at org.junit.runners.model.Statement.evaluate(Statement.java:87)29    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)30    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)31    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)32    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)33    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)34    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)35    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)36    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)37    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)38    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)39    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)40    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)

expect

Using AI Code Generation

1import org.junit.Rule;2import org.junit.Test;3import org.junit.rules.ExpectedException;4public class TestException {5    public ExpectedException thrown = ExpectedException.none();6    public void testException() {7        thrown.expect(ArithmeticException.class);8        thrown.expectMessage("/ by zero");9        int i = 1/0;10    }11}12	at org.junit.rules.ExpectedException$ExpectedExceptionStatement.evaluate(ExpectedException.java:239)13	at org.junit.rules.RunRules.evaluate(RunRules.java:20)14	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)15	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)16	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)17	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)18	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)19	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)20	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)21	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)22	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)23	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)24	at org.junit.runner.JUnitCore.run(JUnitCore.java:115)25	at org.junit.vintage.engine.execution.RunnerExecutor.execute(RunnerExecutor.java:43)26	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)27	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)28	at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)29	at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)30	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)31	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)32	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)33	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)34	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)

expect

Using AI Code Generation

1    public ExpectedException thrown = ExpectedException.none();2    public void testExceptionMessage() {3        thrown.expect(IllegalArgumentException.class);4        thrown.expectMessage("Illegal argument");5        throw new IllegalArgumentException("Illegal argument");6    }

expect

Using AI Code Generation

1import org.junit.Rule;2import org.junit.Test;3import org.junit.rules.ExpectedException;4public class TestException {5    public ExpectedException thrown = ExpectedException.none();6    public void throwsNullPointerException() {7        thrown.expect(NullPointerException.class);8        throw new NullPointerException();9    }10}11BUILD SUCCESSFUL (total time: 0 seconds)

expect

Using AI Code Generation

1public ExpectedException thrown = ExpectedException.none();2public void testExceptionMessage() {3    thrown.expect(IllegalArgumentException.class);4    thrown.expectMessage("exception message");5    throw new IllegalArgumentException("exception message");6}7public void testExceptionMessage() {8    Throwable exception = assertThrows(IllegalArgumentException.class, () -> {9        throw new IllegalArgumentException("exception message");10    });11    assertEquals("exception message", exception.getMessage());12}13public void testExceptionMessage() {14    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {15        throw new IllegalArgumentException("exception message");16    });17    assertEquals("exception message", exception.getMessage());18}19public void testExceptionMessage() {20    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {21        throw new IllegalArgumentException("exception message");22    });23    assertEquals("exception message", exception.getMessage());24}25public void testExceptionMessage() {26    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {27        throw new IllegalArgumentException("exception message");28    });29    assertEquals("exception message", exception.getMessage());30}31public void testExceptionMessage() {32    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {33        throw new IllegalArgumentException("exception message");34    });35    assertEquals("exception message", exception.getMessage());36}37public void testExceptionMessage() {38    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {39        throw new IllegalArgumentException("exception message");40    });41    assertEquals("exception message", exception.getMessage());42}43public void testExceptionMessage() {44    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {45        throw new IllegalArgumentException("exception message");46    });47    assertEquals("exception message", exception.getMessage());48}49public void testExceptionMessage() {50    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {51        throw new IllegalArgumentException("exception message");52    });53    assertEquals("exception message", exception

expect

Using AI Code Generation

1  public void testExceptionMessage() {2    expectedEx.expect(IllegalArgumentException.class);3    expectedEx.expectMessage("Invalid input");4    throw new IllegalArgumentException("Invalid input");5  }6  public void testExceptionMessage() {7    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {8      throw new IllegalArgumentException("Invalid input");9    });10    assertEquals("Invalid input", exception.getMessage());11  }12  public void testExceptionMessage() {13    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {14      throw new IllegalArgumentException("Invalid input");15    });16    assertEquals("Invalid input", exception.getMessage());17  }18  public void testExceptionMessage() {19    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {20      throw new IllegalArgumentException("Invalid input");21    });22    assertEquals("Invalid input", exception.getMessage());23  }24  public void testExceptionMessage() {25    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {26      throw new IllegalArgumentException("Invalid input");27    });28    assertEquals("Invalid input", exception.getMessage());29  }30  public void testExceptionMessage() {31    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {32      throw new IllegalArgumentException("Invalid input");33    });34    assertEquals("Invalid input", exception.getMessage());35  }36  public void testExceptionMessage() {37    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {38      throw new IllegalArgumentException("Invalid input");39    });40    assertEquals("Invalid input", exception.getMessage());41  }42  public void testExceptionMessage() {43    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class, () -> {44      throw new IllegalArgumentException("Invalid input");45    });46    assertEquals("Invalid input", exception.getMessage());47  }48  public void testExceptionMessage() {

expect

Using AI Code Generation

1import org.junit.rules.ExpectedException;2import org.junit.Rule;3import org.junit.Test;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}13The following test method shows how to use expectMessage() method to specify the expected exception message:14public void throwsNullPointerExceptionWithMessage() {15    thrown.expect(NullPointerException.class);16    thrown.expectMessage("Hello");17    throw new NullPointerException("Hello");18}19The following test method shows how to use expectCause() method to specify the expected cause of the exception:20public void throwsNullPointerExceptionWithCause() {21    NullPointerException cause = new NullPointerException();22    thrown.expect(IllegalArgumentException.class);23    thrown.expectCause(is(cause));24    throw new IllegalArgumentException(cause);25}26The following test method shows how to use expectCause() method to specify the expected cause of the exception:27public void throwsNullPointerExceptionWithCause() {28    NullPointerException cause = new NullPointerException();29    thrown.expect(IllegalArgumentException.class);30    thrown.expectCause(is(cause));31    throw new IllegalArgumentException(cause);32}33The following test method shows how to use expectCause() method to specify the expected cause of the exception:34public void throwsNullPointerExceptionWithCause() {35    NullPointerException cause = new NullPointerException();

JUnit Tutorial:

LambdaTest also has a detailed JUnit tutorial explaining its features, importance, advanced use cases, best practices, and more to help you get started with running your automation testing scripts.

JUnit Tutorial Chapters:

Here are the detailed JUnit testing chapters to help you get started:

Importance of Unit testing - Learn why Unit testing is essential during the development phase to identify bugs and errors.
Top Java Unit testing frameworks - Here are the upcoming JUnit automation testing frameworks that you can use in 2023 to boost your unit testing.
What is the JUnit framework
Why is JUnit testing important - Learn the importance and numerous benefits of using the JUnit testing framework.
Features of JUnit - Learn about the numerous features of JUnit and why developers prefer it.
JUnit 5 vs. JUnit 4: Differences - Here is a complete comparison between JUnit 5 and JUnit 4 testing frameworks.
Setting up the JUnit environment - Learn how to set up your JUnit testing environment.
Getting started with JUnit testing - After successfully setting up your JUnit environment, this chapter will help you get started with JUnit testing in no time.
Parallel testing with JUnit - Parallel Testing can be used to reduce test execution time and improve test efficiency. Learn how to perform parallel testing with JUnit.
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.