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

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

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:ExpectedExceptionCheckerTest.java

...17import com.google.errorprone.BugCheckerRefactoringTestHelper;18import org.junit.Test;19import org.junit.runner.RunWith;20import org.junit.runners.JUnit4;21/** {@link ExpectedExceptionChecker}Test. */22@RunWith(JUnit4.class)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());",450            "  }",451            "}")452        .doTest();453  }454}...

Source:JunitRuleTest.java

...3import lombok.extern.slf4j.Slf4j;4import org.apache.commons.io.FileUtils;5import org.junit.Rule;6import org.junit.Test;7import org.junit.rules.ExpectedException;8import org.junit.rules.MethodRule;9import org.junit.rules.RuleChain;10import org.junit.rules.TemporaryFolder;11import org.junit.rules.TestName;12import org.junit.rules.TestRule;13import org.junit.rules.Timeout;14import org.junit.runner.Description;15import org.junit.runner.RunWith;16import org.junit.runners.model.FrameworkMethod;17import org.junit.runners.model.Statement;18import org.springframework.boot.test.context.SpringBootTest;19import org.springframework.test.context.junit4.SpringRunner;20import java.io.File;21import java.util.concurrent.TimeUnit;22/**23 * JunitRuleTest24 *25 * @author dongdaiming(è£ä»£æ)26 * @date 2019-07-2227 * @see <a href="https://blog.csdn.net/kingmax54212008/article/details/89003076">Junit Ruleçä½¿ç¨</a>28 */29@Slf4j30@RunWith(SpringRunner.class)31@SpringBootTest32public class JunitRuleTest {33    // TemporaryFolderå¯ç¨äºå¨æµè¯æ¶çææä»¶å¹¶å¨æµè¯å®åèªå¨å é¤34    @Rule35    public TemporaryFolder temporaryFolder = new TemporaryFolder(new File("/temp/junit"));36    // TestNameå¯ä»¥è·åå°å½åæµè¯æ¹æ³çåç§°37    @Rule38    public TestName testName = new TestName();39    // Timeoutå¯ä»¥è®¾ç½®å¨å±çè¶æ¶æ¶é´40    @Rule41    public Timeout timeout = Timeout.seconds(15);42    // èªå®ä¹æ¹æ³è§å-æå°æµè¯æ¹æ³åä¸èæ¶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    }...

Source:ExpectedException.java

...24import org.junit.runner.Description;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     */...

Source:RulesUnitTest.java

...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 {...

Source:CalacRuleTest.java

...8import org.junit.Before;9import org.junit.BeforeClass;10import org.junit.Rule;11import org.junit.Test;12import org.junit.rules.ExpectedException;13import org.junit.rules.TemporaryFolder;14import org.junit.rules.TestName;15import org.junit.rules.TestWatcher;16import org.junit.rules.Timeout;17import org.junit.runner.Description;18import practice.section1.Calculator;19public class CalacRuleTest {20  @BeforeClass21  public static void setUpBeforeClass() throws Exception {22  }23  @AfterClass24  public static void tearDownAfterClass() throws Exception {25  }26  @Before27  public void setUp() throws Exception {28  }29  @After30  public void tearDown() throws Exception {31  }32  @Rule33  public TemporaryFolder tempFolder = new TemporaryFolder();34  @Rule //ã¿ã¤ã ã¢ã¦ã35  public Timeout timeout = new Timeout(100000);36  @Rule //å®è¡ä¸ã®ãã¹ãã¡ã½ããåãåç§ã§ãã37  public TestName testName = new TestName();38  @Rule //ä¾å¤åºåããããããããã39  public ExpectedException expectedException = ExpectedException.none();40  @Rule //ãã°åºå ãã¹ãã¦ã©ããã£ã¼41  public TestWatcher testWatcher = new TestWatcher () {42    @Override43    protected void starting(Description description) {44      Logger.getAnonymousLogger().info("start:"45      + description.getMethodName());46    }47    @Override48    protected void succeeded(Description description) {49      Logger.getAnonymousLogger().info("succeeded:"50      + description.getMethodName());51    }52    @Override53    protected void failed(Throwable e, Description description) {...

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    }...

Source:JUnit4BuiltInTestRulesTest.java

23import static org.hamcrest.Matchers.is;4import static org.hamcrest.Matchers.isA;5import static org.junit.Assert.assertThat;6import static org.junit.rules.ExpectedException.none;78import java.io.File;9import java.io.IOException;1011import org.junit.Rule;12import org.junit.Test;13import org.junit.rules.ExpectedException;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    }39
...

Source:Rules.java

...4import junitparams.Parameters;5import org.junit.Rule;6import org.junit.Test;7import org.junit.rules.ErrorCollector;8import org.junit.rules.ExpectedException;9import org.junit.rules.TemporaryFolder;10import org.junit.rules.TestName;11import org.junit.rules.TestWatcher;12import org.junit.rules.Timeout;13import org.junit.runner.RunWith;14@RunWith(JUnitParamsRunner.class)15public class Rules {16    @Rule17    public TemporaryFolder folder = new TemporaryFolder();18    @Rule19    public ExpectedException exception = ExpectedException.none();20    @Rule21    public ErrorCollector errors = new ErrorCollector();22    @Rule23    public TestName testName = new TestName();24    @Rule25    public TestWatcher testWatcher = new TestWatcher() {};26    @Rule27    public Timeout timeout = new Timeout(28            0);29    @Test30    @Parameters("test")31    public void shouldHandleRulesWork(String n) {32        assertThat(testName.getMethodName()).isEqualTo("shouldHandleRulesWork");33    }...

ExpectedException

Using AI Code Generation

1import org.junit.Rule;2import org.junit.Test;3import org.junit.rules.ExpectedException;4public class ExpectedExceptionTest {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("happened");15        throw new NullPointerException("what happened?");16    }17    public void throwsNullPointerExceptionWithMessageContaining() {18        thrown.expect(NullPointerException.class);19        thrown.expectMessage("what");20        throw new NullPointerException("what happened?");21    }22}23import org.junit.Rule;24import org.junit.Test;25import org.junit.rules.ExpectedException;26public class ExpectedExceptionTest {27    public ExpectedException thrown = ExpectedException.none();28    public void throwsNothing() {29    }30    public void throwsNullPointerException() {31        thrown.expect(NullPointerException.class);32        throw new NullPointerException();33    }34    public void throwsNullPointerExceptionWithMessage() {35        thrown.expect(NullPointerException.class);36        thrown.expectMessage("happened");37        throw new NullPointerException("what happened?");38    }39    public void throwsNullPointerExceptionWithMessageContaining() {40        thrown.expect(NullPointerException.class);41        thrown.expectMessage("what");42        throw new NullPointerException("what happened?");43    }44}45void expect(Class<? extends

ExpectedException

Using AI Code Generation

1import org.junit.Test;2import org.junit.Rule;3import org.junit.rules.ExpectedException;4import java.io.File;5import java.io.FileNotFoundException;6import java.io.FileReader;7public class ExpectedExceptionTest {8    public ExpectedException thrown = ExpectedException.none();9    public void testExpectedException() throws FileNotFoundException {10        File file = new File("test.txt");11        FileReader fileReader = new FileReader(file);12        thrown.expect(FileNotFoundException.class);13        thrown.expectMessage("test.txt (No such file or directory)");14        fileReader.read();15    }16}17Expected :test.txt (No such file or directory)18Actual   :test.txt (The system cannot find the file specified)19at org.junit.Assert.assertEquals(Assert.java:115)20at org.junit.Assert.assertEquals(Assert.java:144)21at org.junit.rules.ExpectedException$ExpectedExceptionStatement.evaluate(ExpectedException.java:268)22at org.junit.rules.RunRules.evaluate(RunRules.java:20)23at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)24at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)25at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)26at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)27at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)28at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)29at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)30at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)31at org.junit.runners.ParentRunner.run(ParentRunner.java:363)32at org.junit.runner.JUnitCore.run(JUnitCore.java:137)33at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)34at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)35at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)36at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

ExpectedException

Using AI Code Generation

1import org.junit.jupiter.api.Test;2import org.junit.jupiter.api.function.Executable;3import org.junit.jupiter.api.Assertions;4import org.junit.jupiter.api.BeforeEach;5import org.junit.jupiter.api.AfterEach;6public class TestClass {7    private Calculator calculator;8    public void setUp() {9        calculator = new Calculator();10    }11    public void tearDown() {12        calculator = null;13    }14    public void testAdd() {15        int sum = calculator.add(10, 50);16        assertEquals(60, sum);17    }18    public void testSubtract() {19        int difference = calculator.subtract(10, 50);20        assertEquals(-40, difference);21    }22    public void testMultiply() {23        int product = calculator.multiply(10, 50);24        assertEquals(500, product);25    }26    public void testDivide() {27        int quotient = calculator.divide(10, 50);28        assertEquals(0, quotient);29    }30    public void testDivideByZero() {31        Throwable exception = assertThrows(IllegalArgumentException.class, new Executable() {32            public void execute() throws Throwable {33                calculator.divide(10, 0);34            }35        });36        assertEquals("divide by zero", exception.getMessage());37    }38}39package com.javacodegeeks.junit;40public class Calculator {41    public int add(int a, int b) {42        return a + b;43    }44    public int subtract(int a, int b) {45        return a - b;46    }47    public int multiply(int a, int b) {48        return a * b;49    }50    public int divide(int a, int b) {51        if (b == 0) {52            throw new IllegalArgumentException("divide by zero");53        }54        return a / b;55    }56}

ExpectedException

Using AI Code Generation

1import org.junit.rules.ExpectedException;2ExpectedException thrown = ExpectedException.none();3public ExpectedException thrown = ExpectedException.none();4thrown.expect(ArithmeticException.class);5thrown.expectMessage("Divide by zero");6thrown.expectCause(isA(IllegalArgumentException.class));7assertThrows(ArithmeticException.class, () -> { 1/0; });8assertThrows(ArithmeticException.class, () -> { 1/0; },9"Divide by zero");10assertThrows(ArithmeticException.class, () -> { 1/0; },11isA(IllegalArgumentException.class));12assertThrows(ArithmeticException.class, () -> { 1/0; },13"Divide by zero");14assertThrows(ArithmeticException.class, () -> { 1/0; },15isA(IllegalArgumentException.class));

Source: How do you assert that a certain exception is thrown in JUnit 4 tests?

1return userRepository.findById(id)2                .flatMap(target -> userRepository.findById(id2)3                        .map(User::getName)4                        .flatMap(sourceName -> eventRepository.findById(id3)5                                .map(Event::getName)6                                .map(eventName-> createInvite(target, sourceName, eventName))))7

Source:How do you assert that a certain exception is thrown in JUnit 4 tests?

return userRepository.findById(id)
                .flatMap(target -> userRepository.findById(id2)
                        .map(User::getName)
                        .flatMap(sourceName -> eventRepository.findById(id3)
                                .map(Event::getName)
                                .map(eventName-> createInvite(target, sourceName, eventName))))

Source: How do I assert my exception message with JUnit Test annotation?

1try {2  doSomething( optional1.get(), optional2.get(), optional3.get() );3} catch( NoSuchElementException e ) {4  // report, log, do nothing5}6

Source:How do I assert my exception message with JUnit Test annotation?

try {
  doSomething( optional1.get(), optional2.get(), optional3.get() );
} catch( NoSuchElementException e ) {
  // report, log, do nothing
}

Source: How do you assert that a certain exception is thrown in JUnit 4 tests?

1if (maybeTarget.isPresent() && maybeSourceName.isPresent() && maybeEventName.isPresent()) {2 ...3}4

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.