Migrate from ExpectedException rule to AssertJ

Replace ExpectedException JUnit rules with AssertJ exception
assertions.

Closes gh-14336

spring-boot-project/spring-boot-tools/spring-boot-configuration-metadata/src/test/java/org/springframework/boot/configurationmetadata/AbstractConfigurationMetadataTests.java

@@ -19,9 +19,6 @@ package org.springframework.boot.configurationmetadata;
 import java.io.IOException;
 import java.io.InputStream;
 
-import org.junit.Rule;
-import org.junit.rules.ExpectedException;
-
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 
@@ -34,9 +31,6 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 public abstract class AbstractConfigurationMetadataTests {
 
-	@Rule
-	public final ExpectedException thrown = ExpectedException.none();
-
 	protected void assertSource(ConfigurationMetadataSource actual, String groupId,
 			String type, String sourceType) {
 		assertThat(actual).isNotNull();

spring-boot-project/spring-boot-tools/spring-boot-configuration-metadata/src/test/java/org/springframework/boot/configurationmetadata/ConfigurationMetadataRepositoryJsonBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@ import java.util.Map;
 import org.junit.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
 
 /**
  * Tests for {@link ConfigurationMetadataRepository}.
@@ -34,8 +35,9 @@ public class ConfigurationMetadataRepositoryJsonBuilderTests
 
 	@Test
 	public void nullResource() throws IOException {
-		this.thrown.expect(IllegalArgumentException.class);
-		ConfigurationMetadataRepositoryJsonBuilder.create().withJsonResource(null);
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> ConfigurationMetadataRepositoryJsonBuilder.create()
+						.withJsonResource(null));
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-configuration-metadata/src/test/java/org/springframework/boot/configurationmetadata/JsonReaderTests.java

@@ -21,11 +21,11 @@ import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
 
-import org.hamcrest.CoreMatchers;
 import org.json.JSONException;
 import org.junit.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link JsonReader}.
@@ -47,8 +47,8 @@ public class JsonReaderTests extends AbstractConfigurationMetadataTests {
 
 	@Test
 	public void invalidMetadata() throws IOException {
-		this.thrown.expectCause(CoreMatchers.instanceOf(JSONException.class));
-		readFor("invalid");
+		assertThatIllegalStateException().isThrownBy(() -> readFor("invalid"))
+				.withCauseInstanceOf(JSONException.class);
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-configuration-processor/src/test/java/org/springframework/boot/configurationprocessor/ConfigurationMetadataAnnotationProcessorTests.java

@@ -28,7 +28,6 @@ import java.util.stream.Collectors;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
 
 import org.springframework.boot.configurationprocessor.json.JSONArray;
@@ -95,6 +94,7 @@ import org.springframework.boot.testsupport.compiler.TestCompiler;
 import org.springframework.util.FileCopyUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link ConfigurationMetadataAnnotationProcessor}.
@@ -110,9 +110,6 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 	@Rule
 	public TemporaryFolder temporaryFolder = new TemporaryFolder();
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	private TestCompiler compiler;
 
 	@Before
@@ -502,9 +499,9 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 
 	@Test
 	public void invalidDoubleRegistration() {
-		this.thrown.expect(IllegalStateException.class);
-		this.thrown.expectMessage("Compilation failed");
-		compile(InvalidDoubleRegistrationProperties.class);
+		assertThatIllegalStateException()
+				.isThrownBy(() -> compile(InvalidDoubleRegistrationProperties.class))
+				.withMessageContaining("Compilation failed");
 	}
 
 	@Test
@@ -904,10 +901,9 @@ public class ConfigurationMetadataAnnotationProcessorTests {
 	public void mergeOfInvalidAdditionalMetadata() throws IOException {
 		File additionalMetadataFile = createAdditionalMetadataFile();
 		FileCopyUtils.copy("Hello World", new FileWriter(additionalMetadataFile));
-
-		this.thrown.expect(IllegalStateException.class);
-		this.thrown.expectMessage("Compilation failed");
-		compile(SimpleProperties.class);
+		assertThatIllegalStateException()
+				.isThrownBy(() -> compile(SimpleProperties.class))
+				.withMessage("Compilation failed");
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/test/java/org/springframework/boot/loader/tools/LayoutsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,11 +18,10 @@ package org.springframework.boot.loader.tools;
 
 import java.io.File;
 
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link Layouts}.
@@ -32,9 +31,6 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 public class LayoutsTests {
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	@Test
 	public void jarFile() {
 		assertThat(Layouts.forFile(new File("test.jar"))).isInstanceOf(Layouts.Jar.class);
@@ -55,9 +51,9 @@ public class LayoutsTests {
 
 	@Test
 	public void unknownFile() {
-		this.thrown.expect(IllegalStateException.class);
-		this.thrown.expectMessage("Unable to deduce layout for 'test.txt'");
-		Layouts.forFile(new File("test.txt"));
+		assertThatIllegalStateException()
+				.isThrownBy(() -> Layouts.forFile(new File("test.txt")))
+				.withMessageContaining("Unable to deduce layout for 'test.txt'");
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/test/java/org/springframework/boot/loader/tools/MainClassFinderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,7 +23,6 @@ import java.util.List;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
 
 import org.springframework.boot.loader.tools.MainClassFinder.MainClass;
@@ -33,6 +32,7 @@ import org.springframework.boot.loader.tools.sample.ClassWithMainMethod;
 import org.springframework.boot.loader.tools.sample.ClassWithoutMainMethod;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link MainClassFinder}.
@@ -44,9 +44,6 @@ public class MainClassFinderTests {
 	@Rule
 	public TemporaryFolder temporaryFolder = new TemporaryFolder();
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	private TestJarFile testJarFile;
 
 	@Before
@@ -83,10 +80,11 @@ public class MainClassFinderTests {
 	public void findSingleJarSearch() throws Exception {
 		this.testJarFile.addClass("a/B.class", ClassWithMainMethod.class);
 		this.testJarFile.addClass("a/b/c/E.class", ClassWithMainMethod.class);
-		this.thrown.expect(IllegalStateException.class);
-		this.thrown.expectMessage("Unable to find a single main class "
-				+ "from the following candidates [a.B, a.b.c.E]");
-		MainClassFinder.findSingleMainClass(this.testJarFile.getJarFile(), "");
+		assertThatIllegalStateException()
+				.isThrownBy(() -> MainClassFinder
+						.findSingleMainClass(this.testJarFile.getJarFile(), ""))
+				.withMessageContaining("Unable to find a single main class "
+						+ "from the following candidates [a.B, a.b.c.E]");
 	}
 
 	@Test
@@ -138,10 +136,11 @@ public class MainClassFinderTests {
 	public void findSingleFolderSearch() throws Exception {
 		this.testJarFile.addClass("a/B.class", ClassWithMainMethod.class);
 		this.testJarFile.addClass("a/b/c/E.class", ClassWithMainMethod.class);
-		this.thrown.expect(IllegalStateException.class);
-		this.thrown.expectMessage("Unable to find a single main class "
-				+ "from the following candidates [a.B, a.b.c.E]");
-		MainClassFinder.findSingleMainClass(this.testJarFile.getJarSource());
+		assertThatIllegalStateException()
+				.isThrownBy(() -> MainClassFinder
+						.findSingleMainClass(this.testJarFile.getJarSource()))
+				.withMessageContaining("Unable to find a single main class "
+						+ "from the following candidates [a.B, a.b.c.E]");
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/test/java/org/springframework/boot/loader/tools/RepackagerTests.java

@@ -40,7 +40,6 @@ import org.apache.commons.compress.archivers.zip.ZipFile;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
 import org.zeroturnaround.zip.ZipUtil;
 
@@ -49,6 +48,8 @@ import org.springframework.boot.loader.tools.sample.ClassWithoutMainMethod;
 import org.springframework.util.FileCopyUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.BDDMockito.given;
@@ -81,9 +82,6 @@ public class RepackagerTests {
 	@Rule
 	public TemporaryFolder temporaryFolder = new TemporaryFolder();
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	private TestJarFile testJarFile;
 
 	@Before
@@ -93,20 +91,19 @@ public class RepackagerTests {
 
 	@Test
 	public void nullSource() {
-		this.thrown.expect(IllegalArgumentException.class);
-		new Repackager(null);
+		assertThatIllegalArgumentException().isThrownBy(() -> new Repackager(null));
 	}
 
 	@Test
 	public void missingSource() {
-		this.thrown.expect(IllegalArgumentException.class);
-		new Repackager(new File("missing"));
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> new Repackager(new File("missing")));
 	}
 
 	@Test
 	public void directorySource() {
-		this.thrown.expect(IllegalArgumentException.class);
-		new Repackager(this.temporaryFolder.getRoot());
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> new Repackager(this.temporaryFolder.getRoot()));
 	}
 
 	@Test
@@ -177,18 +174,18 @@ public class RepackagerTests {
 		this.testJarFile.addClass("a/b/D.class", ClassWithMainMethod.class);
 		File file = this.testJarFile.getFile();
 		Repackager repackager = new Repackager(file);
-		this.thrown.expect(IllegalStateException.class);
-		this.thrown.expectMessage("Unable to find a single main class "
-				+ "from the following candidates [a.b.C, a.b.D]");
-		repackager.repackage(NO_LIBRARIES);
+		assertThatIllegalStateException()
+				.isThrownBy(() -> repackager.repackage(NO_LIBRARIES))
+				.withMessageContaining("Unable to find a single main class "
+						+ "from the following candidates [a.b.C, a.b.D]");
 	}
 
 	@Test
 	public void noMainClass() throws Exception {
 		this.testJarFile.addClass("a/b/C.class", ClassWithoutMainMethod.class);
-		this.thrown.expect(IllegalStateException.class);
-		this.thrown.expectMessage("Unable to find main class");
-		new Repackager(this.testJarFile.getFile()).repackage(NO_LIBRARIES);
+		assertThatIllegalStateException().isThrownBy(
+				() -> new Repackager(this.testJarFile.getFile()).repackage(NO_LIBRARIES))
+				.withMessageContaining("Unable to find main class");
 	}
 
 	@Test
@@ -255,18 +252,18 @@ public class RepackagerTests {
 	public void nullDestination() throws Exception {
 		this.testJarFile.addClass("a/b/C.class", ClassWithMainMethod.class);
 		Repackager repackager = new Repackager(this.testJarFile.getFile());
-		this.thrown.expect(IllegalArgumentException.class);
-		this.thrown.expectMessage("Invalid destination");
-		repackager.repackage(null, NO_LIBRARIES);
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> repackager.repackage(null, NO_LIBRARIES))
+				.withMessageContaining("Invalid destination");
 	}
 
 	@Test
 	public void destinationIsDirectory() throws Exception {
 		this.testJarFile.addClass("a/b/C.class", ClassWithMainMethod.class);
 		Repackager repackager = new Repackager(this.testJarFile.getFile());
-		this.thrown.expect(IllegalArgumentException.class);
-		this.thrown.expectMessage("Invalid destination");
-		repackager.repackage(this.temporaryFolder.getRoot(), NO_LIBRARIES);
+		assertThatIllegalArgumentException().isThrownBy(
+				() -> repackager.repackage(this.temporaryFolder.getRoot(), NO_LIBRARIES))
+				.withMessageContaining("Invalid destination");
 	}
 
 	@Test
@@ -284,9 +281,9 @@ public class RepackagerTests {
 		this.testJarFile.addClass("a/b/C.class", ClassWithMainMethod.class);
 		File file = this.testJarFile.getFile();
 		Repackager repackager = new Repackager(file);
-		this.thrown.expect(IllegalArgumentException.class);
-		this.thrown.expectMessage("Libraries must not be null");
-		repackager.repackage(file, null);
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> repackager.repackage(file, null))
+				.withMessageContaining("Libraries must not be null");
 	}
 
 	@Test
@@ -327,12 +324,13 @@ public class RepackagerTests {
 		this.testJarFile.addClass("a/b/C.class", ClassWithMainMethod.class);
 		File file = this.testJarFile.getFile();
 		Repackager repackager = new Repackager(file);
-		this.thrown.expect(IllegalStateException.class);
-		this.thrown.expectMessage("Duplicate library");
-		repackager.repackage((callback) -> {
-			callback.library(new Library(libJarFile, LibraryScope.COMPILE, false));
-			callback.library(new Library(libJarFile, LibraryScope.COMPILE, false));
-		});
+		assertThatIllegalStateException()
+				.isThrownBy(() -> repackager.repackage((callback) -> {
+					callback.library(
+							new Library(libJarFile, LibraryScope.COMPILE, false));
+					callback.library(
+							new Library(libJarFile, LibraryScope.COMPILE, false));
+				})).withMessageContaining("Duplicate library");
 	}
 
 	@Test
@@ -421,9 +419,8 @@ public class RepackagerTests {
 	public void nullCustomLayout() throws Exception {
 		this.testJarFile.addClass("a/b/C.class", ClassWithoutMainMethod.class);
 		Repackager repackager = new Repackager(this.testJarFile.getFile());
-		this.thrown.expect(IllegalArgumentException.class);
-		this.thrown.expectMessage("Layout must not be null");
-		repackager.setLayout(null);
+		assertThatIllegalArgumentException().isThrownBy(() -> repackager.setLayout(null))
+				.withMessageContaining("Layout must not be null");
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/PropertiesLauncherTests.java

@@ -32,7 +32,6 @@ import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
 
 import org.springframework.boot.loader.archive.Archive;
@@ -43,6 +42,7 @@ import org.springframework.core.io.FileSystemResource;
 import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link PropertiesLauncher}.
@@ -55,9 +55,6 @@ public class PropertiesLauncherTests {
 	@Rule
 	public OutputCapture output = new OutputCapture();
 
-	@Rule
-	public ExpectedException expected = ExpectedException.none();
-
 	@Rule
 	public TemporaryFolder temporaryFolder = new TemporaryFolder();
 
@@ -102,10 +99,9 @@ public class PropertiesLauncherTests {
 	@Test
 	public void testNonExistentHome() {
 		System.setProperty("loader.home", "src/test/resources/nonexistent");
-		this.expected.expectMessage("Invalid source folder");
-		PropertiesLauncher launcher = new PropertiesLauncher();
-		assertThat(launcher.getHomeDirectory())
-				.isNotEqualTo(new File(System.getProperty("loader.home")));
+		assertThatIllegalStateException().isThrownBy(PropertiesLauncher::new)
+				.withMessageContaining("Invalid source folder")
+				.withCauseInstanceOf(IllegalArgumentException.class);
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/archive/JarFileArchiveTests.java

@@ -31,7 +31,6 @@ import java.util.zip.ZipEntry;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
 
 import org.springframework.boot.loader.TestJarCreator;
@@ -39,7 +38,7 @@ import org.springframework.boot.loader.archive.Archive.Entry;
 import org.springframework.util.FileCopyUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.hamcrest.CoreMatchers.equalTo;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link JarFileArchive}.
@@ -52,9 +51,6 @@ public class JarFileArchiveTests {
 	@Rule
 	public TemporaryFolder temporaryFolder = new TemporaryFolder();
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	private File rootJarFile;
 
 	private JarFileArchive archive;
@@ -135,8 +131,8 @@ public class JarFileArchiveTests {
 	public void zip64ArchivesAreHandledGracefully() throws IOException {
 		File file = this.temporaryFolder.newFile("test.jar");
 		FileCopyUtils.copy(writeZip64Jar(), file);
-		this.thrown.expectMessage(equalTo("Zip64 archives are not supported"));
-		new JarFileArchive(file);
+		assertThatIllegalStateException().isThrownBy(() -> new JarFileArchive(file))
+				.withMessageContaining("Zip64 archives are not supported");
 	}
 
 	@Test
@@ -156,10 +152,11 @@ public class JarFileArchiveTests {
 		output.closeEntry();
 		output.close();
 		JarFileArchive jarFileArchive = new JarFileArchive(file);
-		this.thrown.expectMessage(
-				equalTo("Failed to get nested archive for entry nested/zip64.jar"));
-		jarFileArchive
-				.getNestedArchive(getEntriesMap(jarFileArchive).get("nested/zip64.jar"));
+		assertThatIllegalStateException()
+				.isThrownBy(() -> jarFileArchive.getNestedArchive(
+						getEntriesMap(jarFileArchive).get("nested/zip64.jar")))
+				.withMessageContaining(
+						"Failed to get nested archive for entry nested/zip64.jar");
 	}
 
 	private byte[] writeZip64Jar() throws IOException {

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/data/RandomAccessDataFileTests.java

@@ -31,10 +31,12 @@ import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.Assertions.assertThatNullPointerException;
 
 /**
  * Tests for {@link RandomAccessDataFile}.
@@ -53,9 +55,6 @@ public class RandomAccessDataFileTests {
 		}
 	}
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	@Rule
 	public TemporaryFolder temporaryFolder = new TemporaryFolder();
 
@@ -83,18 +82,17 @@ public class RandomAccessDataFileTests {
 
 	@Test
 	public void fileNotNull() {
-		this.thrown.expect(IllegalArgumentException.class);
-		this.thrown.expectMessage("File must not be null");
-		new RandomAccessDataFile(null);
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> new RandomAccessDataFile(null))
+				.withMessageContaining("File must not be null");
 	}
 
 	@Test
 	public void fileExists() {
 		File file = new File("/does/not/exist");
-		this.thrown.expect(IllegalArgumentException.class);
-		this.thrown.expectMessage(
-				String.format("File %s must exist", file.getAbsolutePath()));
-		new RandomAccessDataFile(file);
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> new RandomAccessDataFile(file)).withMessageContaining(
+						String.format("File %s must exist", file.getAbsolutePath()));
 	}
 
 	@Test
@@ -105,31 +103,31 @@ public class RandomAccessDataFileTests {
 
 	@Test
 	public void readWhenOffsetIsBeyondEOFShouldThrowException() throws Exception {
-		this.thrown.expect(IndexOutOfBoundsException.class);
-		this.file.read(257, 0);
+		assertThatExceptionOfType(IndexOutOfBoundsException.class)
+				.isThrownBy(() -> this.file.read(257, 0));
 	}
 
 	@Test
 	public void readWhenOffsetIsBeyondEndOfSubsectionShouldThrowException()
 			throws Exception {
-		this.thrown.expect(IndexOutOfBoundsException.class);
 		RandomAccessData subsection = this.file.getSubsection(0, 10);
-		subsection.read(11, 0);
+		assertThatExceptionOfType(IndexOutOfBoundsException.class)
+				.isThrownBy(() -> subsection.read(11, 0));
 	}
 
 	@Test
 	public void readWhenOffsetPlusLengthGreaterThanEOFShouldThrowException()
 			throws Exception {
-		this.thrown.expect(EOFException.class);
-		this.file.read(256, 1);
+		assertThatExceptionOfType(EOFException.class)
+				.isThrownBy(() -> this.file.read(256, 1));
 	}
 
 	@Test
 	public void readWhenOffsetPlusLengthGreaterThanEndOfSubsectionShouldThrowException()
 			throws Exception {
-		this.thrown.expect(EOFException.class);
 		RandomAccessData subsection = this.file.getSubsection(0, 10);
-		subsection.read(10, 1);
+		assertThatExceptionOfType(EOFException.class)
+				.isThrownBy(() -> subsection.read(10, 1));
 	}
 
 	@Test
@@ -141,16 +139,15 @@ public class RandomAccessDataFileTests {
 
 	@Test
 	public void inputStreamReadNullBytes() throws Exception {
-		this.thrown.expect(NullPointerException.class);
-		this.thrown.expectMessage("Bytes must not be null");
-		this.inputStream.read(null);
+		assertThatNullPointerException().isThrownBy(() -> this.inputStream.read(null))
+				.withMessage("Bytes must not be null");
 	}
 
 	@Test
 	public void inputStreamReadNullBytesWithOffset() throws Exception {
-		this.thrown.expect(NullPointerException.class);
-		this.thrown.expectMessage("Bytes must not be null");
-		this.inputStream.read(null, 0, 1);
+		assertThatNullPointerException()
+				.isThrownBy(() -> this.inputStream.read(null, 0, 1))
+				.withMessage("Bytes must not be null");
 	}
 
 	@Test
@@ -218,14 +215,14 @@ public class RandomAccessDataFileTests {
 
 	@Test
 	public void subsectionNegativeOffset() {
-		this.thrown.expect(IndexOutOfBoundsException.class);
-		this.file.getSubsection(-1, 1);
+		assertThatExceptionOfType(IndexOutOfBoundsException.class)
+				.isThrownBy(() -> this.file.getSubsection(-1, 1));
 	}
 
 	@Test
 	public void subsectionNegativeLength() {
-		this.thrown.expect(IndexOutOfBoundsException.class);
-		this.file.getSubsection(0, -1);
+		assertThatExceptionOfType(IndexOutOfBoundsException.class)
+				.isThrownBy(() -> this.file.getSubsection(0, -1));
 	}
 
 	@Test
@@ -237,15 +234,15 @@ public class RandomAccessDataFileTests {
 	@Test
 	public void subsectionTooBig() {
 		this.file.getSubsection(0, 256);
-		this.thrown.expect(IndexOutOfBoundsException.class);
-		this.file.getSubsection(0, 257);
+		assertThatExceptionOfType(IndexOutOfBoundsException.class)
+				.isThrownBy(() -> this.file.getSubsection(0, 257));
 	}
 
 	@Test
 	public void subsectionTooBigWithOffset() {
 		this.file.getSubsection(1, 255);
-		this.thrown.expect(IndexOutOfBoundsException.class);
-		this.file.getSubsection(1, 256);
+		assertThatExceptionOfType(IndexOutOfBoundsException.class)
+				.isThrownBy(() -> this.file.getSubsection(1, 256));
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/AsciiBytesTests.java

@@ -16,11 +16,10 @@
 
 package org.springframework.boot.loader.jar;
 
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
 /**
  * Tests for {@link AsciiBytes}.
@@ -32,9 +31,6 @@ public class AsciiBytesTests {
 
 	private static final char NO_SUFFIX = 0;
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	@Test
 	public void createFromBytes() {
 		AsciiBytes bytes = new AsciiBytes(new byte[] { 65, 66 });
@@ -93,8 +89,8 @@ public class AsciiBytesTests {
 		assertThat(abcd.substring(2).toString()).isEqualTo("CD");
 		assertThat(abcd.substring(3).toString()).isEqualTo("D");
 		assertThat(abcd.substring(4).toString()).isEqualTo("");
-		this.thrown.expect(IndexOutOfBoundsException.class);
-		abcd.substring(5);
+		assertThatExceptionOfType(IndexOutOfBoundsException.class)
+				.isThrownBy(() -> abcd.substring(5));
 	}
 
 	@Test
@@ -104,8 +100,8 @@ public class AsciiBytesTests {
 		assertThat(abcd.substring(1, 3).toString()).isEqualTo("BC");
 		assertThat(abcd.substring(3, 4).toString()).isEqualTo("D");
 		assertThat(abcd.substring(3, 3).toString()).isEqualTo("");
-		this.thrown.expect(IndexOutOfBoundsException.class);
-		abcd.substring(3, 5);
+		assertThatExceptionOfType(IndexOutOfBoundsException.class)
+				.isThrownBy(() -> abcd.substring(3, 5));
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/JarFileTests.java

@@ -21,7 +21,6 @@ import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.FilePermission;
-import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
 import java.net.URLClassLoader;
@@ -36,7 +35,6 @@ import java.util.zip.ZipFile;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
 
 import org.springframework.boot.loader.TestJarCreator;
@@ -45,6 +43,8 @@ import org.springframework.util.FileCopyUtils;
 import org.springframework.util.StreamUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatIOException;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
 
@@ -61,9 +61,6 @@ public class JarFileTests {
 
 	private static final String HANDLERS_PACKAGE = "org.springframework.boot.loader";
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	@Rule
 	public TemporaryFolder temporaryFolder = new TemporaryFolder();
 
@@ -231,16 +228,15 @@ public class JarFileTests {
 		URL url = new URL(this.jarFile.getUrl(), "missing.dat");
 		assertThat(url.toString())
 				.isEqualTo("jar:" + this.rootJarFile.toURI() + "!/missing.dat");
-		this.thrown.expect(FileNotFoundException.class);
-		((JarURLConnection) url.openConnection()).getJarEntry();
+		assertThatExceptionOfType(FileNotFoundException.class)
+				.isThrownBy(((JarURLConnection) url.openConnection())::getJarEntry);
 	}
 
 	@Test
 	public void getUrlStream() throws Exception {
 		URL url = this.jarFile.getUrl();
 		url.openConnection();
-		this.thrown.expect(IOException.class);
-		url.openStream();
+		assertThatIOException().isThrownBy(url::openStream);
 	}
 
 	@Test
@@ -432,8 +428,8 @@ public class JarFileTests {
 				.getNestedJarFile(this.jarFile.getEntry("nested.jar"));
 		URL nestedUrl = nestedJarFile.getUrl();
 		URL url = new URL(nestedUrl, nestedJarFile.getUrl() + "missing.jar!/3.dat");
-		this.thrown.expect(FileNotFoundException.class);
-		url.openConnection().getInputStream();
+		assertThatExceptionOfType(FileNotFoundException.class)
+				.isThrownBy(url.openConnection()::getInputStream);
 	}
 
 	@Test
@@ -494,9 +490,9 @@ public class JarFileTests {
 			URL context = nested.getUrl();
 			new URL(context, "jar:" + this.rootJarFile.toURI() + "!/nested.jar!/3.dat")
 					.openConnection().getInputStream().close();
-			this.thrown.expect(FileNotFoundException.class);
-			new URL(context, "jar:" + this.rootJarFile.toURI() + "!/no.dat")
-					.openConnection().getInputStream();
+			assertThatExceptionOfType(FileNotFoundException.class).isThrownBy(
+					new URL(context, "jar:" + this.rootJarFile.toURI() + "!/no.dat")
+							.openConnection()::getInputStream);
 		}
 		finally {
 			JarURLConnection.setUseFastExceptions(false);

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/JarURLConnectionTests.java

@@ -24,13 +24,13 @@ import java.net.URL;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
 
 import org.springframework.boot.loader.TestJarCreator;
 import org.springframework.boot.loader.jar.JarURLConnection.JarEntryName;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
 /**
  * Tests for {@link JarURLConnection}.
@@ -44,9 +44,6 @@ public class JarURLConnectionTests {
 	@Rule
 	public TemporaryFolder temporaryFolder = new TemporaryFolder(new File("target"));
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	private File rootJarFile;
 
 	private JarFile jarFile;
@@ -160,8 +157,8 @@ public class JarURLConnectionTests {
 		URL url = new URL("jar:file:" + getAbsolutePath() + "!/w.jar!/3.dat");
 		JarFile nested = this.jarFile
 				.getNestedJarFile(this.jarFile.getEntry("nested.jar"));
-		this.thrown.expect(FileNotFoundException.class);
-		JarURLConnection.get(url, nested).getInputStream();
+		assertThatExceptionOfType(FileNotFoundException.class)
+				.isThrownBy(JarURLConnection.get(url, nested)::getInputStream);
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/StringSequenceTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,11 +16,11 @@
 
 package org.springframework.boot.loader.jar;
 
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatNullPointerException;
 
 /**
  * Tests for {@link StringSequence}.
@@ -29,33 +29,28 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 public class StringSequenceTests {
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	@Test
 	public void createWhenSourceIsNullShouldThrowException() {
-		this.thrown.expect(NullPointerException.class);
-		this.thrown.expectMessage("Source must not be null");
-		new StringSequence(null);
+		assertThatNullPointerException().isThrownBy(() -> new StringSequence(null))
+				.withMessage("Source must not be null");
 	}
 
 	@Test
 	public void createWithIndexWhenSourceIsNullShouldThrowException() {
-		this.thrown.expect(NullPointerException.class);
-		this.thrown.expectMessage("Source must not be null");
-		new StringSequence(null, 0, 0);
+		assertThatNullPointerException().isThrownBy(() -> new StringSequence(null, 0, 0))
+				.withMessage("Source must not be null");
 	}
 
 	@Test
 	public void createWhenStartIsLessThanZeroShouldThrowException() {
-		this.thrown.expect(StringIndexOutOfBoundsException.class);
-		new StringSequence("x", -1, 0);
+		assertThatExceptionOfType(StringIndexOutOfBoundsException.class)
+				.isThrownBy(() -> new StringSequence("x", -1, 0));
 	}
 
 	@Test
 	public void createWhenEndIsGreaterThanLengthShouldThrowException() {
-		this.thrown.expect(StringIndexOutOfBoundsException.class);
-		new StringSequence("x", 0, 2);
+		assertThatExceptionOfType(StringIndexOutOfBoundsException.class)
+				.isThrownBy(() -> new StringSequence("x", 0, 2));
 	}
 
 	@Test
@@ -88,8 +83,8 @@ public class StringSequenceTests {
 		StringSequence sequence = new StringSequence("abcde").subSequence(1, 4);
 		assertThat(sequence.toString()).isEqualTo("bcd");
 		assertThat(sequence.subSequence(2, 3).toString()).isEqualTo("d");
-		this.thrown.expect(IndexOutOfBoundsException.class);
-		sequence.subSequence(3, 4);
+		assertThatExceptionOfType(IndexOutOfBoundsException.class)
+				.isThrownBy(() -> sequence.subSequence(3, 4));
 	}
 
 	@Test
@@ -97,8 +92,8 @@ public class StringSequenceTests {
 		StringSequence sequence = new StringSequence("abcde").subSequence(1, 4);
 		assertThat(sequence.toString()).isEqualTo("bcd");
 		assertThat(sequence.subSequence(2, 3).toString()).isEqualTo("d");
-		this.thrown.expect(IndexOutOfBoundsException.class);
-		sequence.subSequence(4, 3);
+		assertThatExceptionOfType(IndexOutOfBoundsException.class)
+				.isThrownBy(() -> sequence.subSequence(4, 3));
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-test-support/src/test/java/org/springframework/boot/testsupport/assertj/MatchedTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,11 +16,10 @@
 
 package org.springframework.boot.testsupport.assertj;
 
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.hamcrest.Matchers.startsWith;
 
 /**
@@ -30,9 +29,6 @@ import static org.hamcrest.Matchers.startsWith;
  */
 public class MatchedTests {
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	@Test
 	public void byMatcherMatches() {
 		assertThat("1234").is(Matched.by(startsWith("12")));
@@ -40,9 +36,9 @@ public class MatchedTests {
 
 	@Test
 	public void byMatcherDoesNotMatch() {
-		this.thrown.expect(AssertionError.class);
-		this.thrown.expectMessage("a string starting with \"23\"");
-		assertThat("1234").is(Matched.by(startsWith("23")));
+		assertThatExceptionOfType(AssertionError.class)
+				.isThrownBy(() -> assertThat("1234").is(Matched.by(startsWith("23"))))
+				.withMessageContaining("a string starting with \"23\"");
 	}
 
 	@Test
@@ -52,9 +48,9 @@ public class MatchedTests {
 
 	@Test
 	public void whenMatcherDoesNotMatch() {
-		this.thrown.expect(AssertionError.class);
-		this.thrown.expectMessage("a string starting with \"23\"");
-		assertThat("1234").is(Matched.when(startsWith("23")));
+		assertThatExceptionOfType(AssertionError.class)
+				.isThrownBy(() -> assertThat("1234").is(Matched.when(startsWith("23"))))
+				.withMessageContaining("a string starting with \"23\"");
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-test-support/src/test/java/org/springframework/boot/testsupport/runner/classpath/ModifiedClassPathRunnerExclusionsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,9 +16,8 @@
 
 package org.springframework.boot.testsupport.runner.classpath;
 
-import org.junit.Rule;
+import org.hamcrest.Matcher;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -36,9 +35,6 @@ public class ModifiedClassPathRunnerExclusionsTests {
 	private static final String EXCLUDED_RESOURCE = "META-INF/services/"
 			+ "javax.validation.spi.ValidationProvider";
 
-	@Rule
-	public ExpectedException thrown = ExpectedException.none();
-
 	@Test
 	public void entriesAreFilteredFromTestClassClassLoader() {
 		assertThat(getClass().getClassLoader().getResource(EXCLUDED_RESOURCE)).isNull();
@@ -52,8 +48,8 @@ public class ModifiedClassPathRunnerExclusionsTests {
 
 	@Test
 	public void testsThatUseHamcrestWorkCorrectly() {
-		this.thrown.expect(isA(IllegalStateException.class));
-		throw new IllegalStateException();
+		Matcher<IllegalStateException> matcher = isA(IllegalStateException.class);
+		assertThat(matcher.matches(new IllegalStateException())).isTrue();
 	}
 
 }