Use Java 9 collection factory methods

Author: marcphilipp

platform-tests/src/test/java/org/junit/platform/commons/util/AnnotationUtilsTests.java

@@ -10,7 +10,6 @@
 
 package org.junit.platform.commons.util;
 
-import static java.util.Arrays.asList;
 import static java.util.stream.Collectors.toList;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -239,7 +238,7 @@ void findRepeatableAnnotationsWithComposedTagBeforeContainer() {
 	}
 
 	private void assertTagsFound(Class<?> clazz, String... tags) {
-		assertEquals(asList(tags),
+		assertEquals(List.of(tags),
 			findRepeatableAnnotations(clazz, Tag.class).stream().map(Tag::value).collect(toList()),
 			() -> "Tags found for class " + clazz.getName());
 	}
@@ -297,7 +296,7 @@ void findInheritedRepeatableAnnotationsWithMultipleComposedAnnotationsOnSupercla
 	}
 
 	private void assertExtensionsFound(Class<?> clazz, String... tags) {
-		assertEquals(asList(tags),
+		assertEquals(List.of(tags),
 			findRepeatableAnnotations(clazz, ExtendWith.class).stream().map(ExtendWith::value).collect(toList()),
 			() -> "Extensions found for class " + clazz.getName());
 	}
@@ -490,22 +489,22 @@ void findPublicAnnotatedFieldsForDirectlyAnnotatedFieldOfWrongFieldType() {
 	void findPublicAnnotatedFieldsForDirectlyAnnotatedField() {
 		var fields = findPublicAnnotatedFields(getClass(), String.class, Annotation1.class);
 		assertNotNull(fields);
-		assertIterableEquals(asList("directlyAnnotatedField"), asNames(fields));
+		assertIterableEquals(List.of("directlyAnnotatedField"), asNames(fields));
 	}
 
 	@Test
 	void findPublicAnnotatedFieldsForMetaAnnotatedField() {
 		var fields = findPublicAnnotatedFields(getClass(), Number.class, Annotation1.class);
 		assertNotNull(fields);
 		assertEquals(1, fields.size());
-		assertIterableEquals(asList("metaAnnotatedField"), asNames(fields));
+		assertIterableEquals(List.of("metaAnnotatedField"), asNames(fields));
 	}
 
 	@Test
 	void findPublicAnnotatedFieldsForDirectlyAnnotatedFieldInInterface() {
 		var fields = findPublicAnnotatedFields(InterfaceWithAnnotatedFields.class, String.class, Annotation1.class);
 		assertNotNull(fields);
-		assertIterableEquals(asList("foo"), asNames(fields));
+		assertIterableEquals(List.of("foo"), asNames(fields));
 	}
 
 	@Test

platform-tests/src/test/java/org/junit/platform/commons/util/ClassNamePatternFilterUtilsTests.java

@@ -10,7 +10,6 @@
 
 package org.junit.platform.commons.util;
 
-import static java.util.Arrays.asList;
 import static org.assertj.core.api.Assertions.assertThat;
 
 import java.util.List;
@@ -47,7 +46,7 @@ class ClassNamePatternFilterUtilsTests {
 	//@formatter:on
 	@ParameterizedTest
 	void alwaysEnabledConditions(String pattern) {
-		List<? extends ExecutionCondition> executionConditions = asList(new AExecutionConditionClass(),
+		List<? extends ExecutionCondition> executionConditions = List.of(new AExecutionConditionClass(),
 			new BExecutionConditionClass());
 		assertThat(executionConditions).filteredOn(
 			ClassNamePatternFilterUtils.excludeMatchingClasses(pattern)).isNotEmpty();
@@ -64,7 +63,7 @@ void alwaysEnabledConditions(String pattern) {
 	//@formatter:on
 	@ParameterizedTest
 	void alwaysDisabledConditions(String pattern) {
-		List<? extends ExecutionCondition> executionConditions = asList(new AExecutionConditionClass(),
+		List<? extends ExecutionCondition> executionConditions = List.of(new AExecutionConditionClass(),
 			new BExecutionConditionClass());
 		assertThat(executionConditions).filteredOn(
 			ClassNamePatternFilterUtils.excludeMatchingClasses(pattern)).isEmpty();
@@ -81,7 +80,7 @@ void alwaysDisabledConditions(String pattern) {
 	//@formatter:on
 	@ParameterizedTest
 	void alwaysEnabledListeners(String pattern) {
-		List<? extends TestExecutionListener> executionConditions = asList(new ATestExecutionListenerClass(),
+		List<? extends TestExecutionListener> executionConditions = List.of(new ATestExecutionListenerClass(),
 			new BTestExecutionListenerClass());
 		assertThat(executionConditions).filteredOn(
 			ClassNamePatternFilterUtils.excludeMatchingClasses(pattern)).isNotEmpty();
@@ -98,7 +97,7 @@ void alwaysEnabledListeners(String pattern) {
 	//@formatter:on
 	@ParameterizedTest
 	void alwaysDisabledListeners(String pattern) {
-		List<? extends TestExecutionListener> executionConditions = asList(new ATestExecutionListenerClass(),
+		List<? extends TestExecutionListener> executionConditions = List.of(new ATestExecutionListenerClass(),
 			new BTestExecutionListenerClass());
 		assertThat(executionConditions).filteredOn(
 			ClassNamePatternFilterUtils.excludeMatchingClasses(pattern)).isEmpty();
@@ -115,7 +114,7 @@ void alwaysDisabledListeners(String pattern) {
 	//@formatter:on
 	@ParameterizedTest
 	void alwaysEnabledClass(String pattern) {
-		var executionConditions = asList(new AVanillaEmpty(), new BVanillaEmpty());
+		var executionConditions = List.of(new AVanillaEmpty(), new BVanillaEmpty());
 		assertThat(executionConditions).filteredOn(
 			ClassNamePatternFilterUtils.excludeMatchingClasses(pattern)).isNotEmpty();
 	}
@@ -131,7 +130,7 @@ void alwaysEnabledClass(String pattern) {
 	//@formatter:on
 	@ParameterizedTest
 	void alwaysDisabledClass(String pattern) {
-		var executionConditions = asList(new AVanillaEmpty(), new BVanillaEmpty());
+		var executionConditions = List.of(new AVanillaEmpty(), new BVanillaEmpty());
 		assertThat(executionConditions).filteredOn(
 			ClassNamePatternFilterUtils.excludeMatchingClasses(pattern)).isEmpty();
 	}

platform-tests/src/test/java/org/junit/platform/commons/util/CollectionUtilsTests.java

@@ -10,9 +10,6 @@
 
 package org.junit.platform.commons.util;
 
-import static java.util.Arrays.asList;
-import static java.util.Collections.emptySet;
-import static java.util.Collections.singleton;
 import static java.util.stream.Collectors.toList;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -25,6 +22,8 @@
 import java.lang.reflect.Array;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
+import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.DoubleStream;
 import java.util.stream.IntStream;
@@ -52,21 +51,21 @@ void getOnlyElementWithNullCollection() {
 	@Test
 	void getOnlyElementWithEmptyCollection() {
 		var exception = assertThrows(PreconditionViolationException.class,
-			() -> CollectionUtils.getOnlyElement(emptySet()));
+			() -> CollectionUtils.getOnlyElement(Set.of()));
 		assertEquals("collection must contain exactly one element: []", exception.getMessage());
 	}
 
 	@Test
 	void getOnlyElementWithSingleElementCollection() {
 		var expected = new Object();
-		var actual = CollectionUtils.getOnlyElement(singleton(expected));
+		var actual = CollectionUtils.getOnlyElement(Set.of(expected));
 		assertSame(expected, actual);
 	}
 
 	@Test
 	void getOnlyElementWithMultiElementCollection() {
 		var exception = assertThrows(PreconditionViolationException.class,
-			() -> CollectionUtils.getOnlyElement(asList("foo", "bar")));
+			() -> CollectionUtils.getOnlyElement(List.of("foo", "bar")));
 		assertEquals("collection must contain exactly one element: [foo, bar]", exception.getMessage());
 	}
 
@@ -159,7 +158,7 @@ public Stream<String> stream() {
 	@SuppressWarnings("unchecked")
 	void toStreamWithIterable() {
 
-		Iterable<String> input = () -> asList("foo", "bar").iterator();
+		Iterable<String> input = () -> List.of("foo", "bar").iterator();
 
 		var result = (Stream<String>) CollectionUtils.toStream(input);
 
@@ -169,7 +168,7 @@ void toStreamWithIterable() {
 	@Test
 	@SuppressWarnings("unchecked")
 	void toStreamWithIterator() {
-		var input = asList("foo", "bar").iterator();
+		var input = List.of("foo", "bar").iterator();
 
 		var result = (Stream<String>) CollectionUtils.toStream(input);
 

platform-tests/src/test/java/org/junit/platform/commons/util/PackageUtilsTests.java

@@ -16,7 +16,6 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.DynamicTest.dynamicTest;
 
-import java.util.Arrays;
 import java.util.List;
 import java.util.function.Function;
 
@@ -91,13 +90,15 @@ void getAttributeFromDefaultPackageMemberIsEmpty() throws Exception {
 
 	@TestFactory
 	List<DynamicTest> attributesFromValueWrapperClassArePresent() {
-		return Arrays.asList(dynamicTest("getName", isPresent(Package::getName)),
+		return List.of( //
+			dynamicTest("getName", isPresent(Package::getName)),
 			dynamicTest("getImplementationTitle", isPresent(Package::getImplementationTitle)),
 			dynamicTest("getImplementationVendor", isPresent(Package::getImplementationVendor)),
 			dynamicTest("getImplementationVersion", isPresent(Package::getImplementationVersion)),
 			dynamicTest("getSpecificationTitle", isPresent(Package::getSpecificationTitle)),
 			dynamicTest("getSpecificationVendor", isPresent(Package::getSpecificationVendor)),
-			dynamicTest("getSpecificationVersion", isPresent(Package::getSpecificationVersion)));
+			dynamicTest("getSpecificationVersion", isPresent(Package::getSpecificationVersion)) //
+		);
 	}
 
 	private Executable isPresent(Function<Package, String> function) {

platform-tests/src/test/java/org/junit/platform/commons/util/PreconditionsTests.java

@@ -10,7 +10,6 @@
 
 package org.junit.platform.commons.util;
 
-import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertSame;
@@ -21,7 +20,6 @@
 import static org.junit.platform.commons.util.Preconditions.notEmpty;
 import static org.junit.platform.commons.util.Preconditions.notNull;
 
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 
@@ -70,7 +68,7 @@ void notEmptyPassesForNonEmptyArray() {
 
 	@Test
 	void notEmptyPassesForNonEmptyCollection() {
-		Collection<String> collection = Arrays.asList("a", "b", "c");
+		Collection<String> collection = List.of("a", "b", "c");
 		var nonEmptyCollection = notEmpty(collection, () -> "should not fail");
 		assertSame(collection, nonEmptyCollection);
 	}
@@ -117,7 +115,7 @@ void notEmptyThrowsForEmptyArray() {
 	void notEmptyThrowsForEmptyCollection() {
 		var message = "collection is empty";
 
-		var exception = assertThrows(PreconditionViolationException.class, () -> notEmpty(emptyList(), message));
+		var exception = assertThrows(PreconditionViolationException.class, () -> notEmpty(List.of(), message));
 
 		assertEquals(message, exception.getMessage());
 	}
@@ -134,10 +132,10 @@ void containsNoNullElementsPassesForArrayThatIsNullOrEmpty() {
 	@Test
 	void containsNoNullElementsPassesForCollectionThatIsNullOrEmpty() {
 		containsNoNullElements((List<?>) null, "collection is null");
-		containsNoNullElements(emptyList(), "collection is empty");
+		containsNoNullElements(List.of(), "collection is empty");
 
 		containsNoNullElements((List<?>) null, () -> "collection is null");
-		containsNoNullElements(emptyList(), () -> "collection is empty");
+		containsNoNullElements(List.of(), () -> "collection is empty");
 	}
 
 	@Test
@@ -149,7 +147,7 @@ void containsNoNullElementsPassesForArrayContainingNonNullElements() {
 
 	@Test
 	void containsNoNullElementsPassesForCollectionContainingNonNullElements() {
-		Collection<String> input = Arrays.asList("a", "b", "c");
+		var input = List.of("a", "b", "c");
 		var output = containsNoNullElements(input, "message");
 		assertSame(input, output);
 

platform-tests/src/test/java/org/junit/platform/console/ConsoleDetailsTests.java

@@ -12,7 +12,6 @@
 
 import static java.lang.String.format;
 import static java.nio.charset.StandardCharsets.UTF_8;
-import static java.util.Arrays.asList;
 import static org.junit.jupiter.api.Assertions.assertLinesMatch;
 import static org.junit.jupiter.api.Assertions.fail;
 import static org.junit.jupiter.api.Assumptions.assumeTrue;
@@ -229,7 +228,7 @@ public void execute() throws Throwable {
 			assumeTrue(Files.isReadable(path), "can not read: " + path);
 
 			var expectedLines = Files.readAllLines(path, UTF_8);
-			var actualLines = asList(result.out.split("\\R"));
+			var actualLines = List.of(result.out.split("\\R"));
 
 			assertLinesMatch(expectedLines, actualLines);
 		}