Add selectClasspathResources(String...) to discovery selectors

documentation/modules/ROOT/partials/release-notes/release-notes-6.1.0-M2.adoc

@@ -30,6 +30,7 @@ repository on GitHub.
 
 * The `UniqueId.uniqueIdFormat` field has been removed, reducing the size of `UniqueId`
   objects.
+* Add `DiscoverySelectors.selectClasspathResources(String...)` and `DiscoverySelectors.selectClasspathResources(List<String)`
 
 [[v6.1.0-M2-junit-jupiter]]
 === JUnit Jupiter

junit-platform-commons/src/main/java/org/junit/platform/commons/util/Preconditions.java

@@ -270,6 +270,56 @@ public static <T extends Collection<?>> T notEmpty(@Nullable T collection, Suppl
 		return collection;
 	}
 
+	/**
+	 * Assert that the supplied collection contains no blank elements.
+	 *
+	 * <p><strong>WARNING</strong>: this method does NOT check if the supplied
+	 * collection is {@code null} or <em>empty</em>.
+	 *
+	 * @param collection the collection to check
+	 * @param message precondition violation message
+	 * @return the supplied collection as a convenience
+	 * @throws PreconditionViolationException if the supplied collection contains
+	 * any blank elements
+	 * @since 6.1
+	 * @see #notBlank(String, String)
+	 */
+	@API(status = INTERNAL, since = "6.1")
+	@Contract("null, _ -> null")
+	public static <T extends Collection<String>> @Nullable T containsNoBlankElements(@Nullable T collection,
+			String message) throws PreconditionViolationException {
+
+		if (collection != null) {
+			collection.forEach(object -> notBlank(object, message));
+		}
+		return collection;
+	}
+
+	/**
+	 * Assert that the supplied collection contains no blank elements.
+	 *
+	 * <p><strong>WARNING</strong>: this method does NOT check if the supplied
+	 * collection is {@code null} or <em>empty</em>.
+	 *
+	 * @param collection the collection to check
+	 * @param messageSupplier precondition violation message supplier
+	 * @return the supplied collection as a convenience
+	 * @throws PreconditionViolationException if the supplied collection contains
+	 * any blank elements
+	 * @since 6.1
+	 * @see #notBlank(String, String)
+	 */
+	@API(status = INTERNAL, since = "6.1")
+	@Contract("null, _ -> null")
+	public static <T extends Collection<String>> @Nullable T containsNoBlankElements(@Nullable T collection,
+			Supplier<String> messageSupplier) throws PreconditionViolationException {
+
+		if (collection != null) {
+			collection.forEach(object -> notBlank(object, messageSupplier));
+		}
+		return collection;
+	}
+
 	/**
 	 * Assert that the supplied {@link String} is not blank.
 	 *

junit-platform-engine/src/main/java/org/junit/platform/engine/discovery/DiscoverySelectors.java

@@ -22,6 +22,7 @@
 import java.net.URISyntaxException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
@@ -292,6 +293,7 @@ public static List<ClasspathRootSelector> selectClasspathRoots(Set<Path> classpa
 	 * @param classpathResourceName the name of the classpath resource; never
 	 * {@code null} or blank
 	 * @see #selectClasspathResource(String, FilePosition)
+	 * @see #selectClasspathResources(String...)
 	 * @see #selectClasspathResourceByName(Set)
 	 * @see ClasspathResourceSelector
 	 * @see ClassLoader#getResource(String)
@@ -322,6 +324,7 @@ public static ClasspathResourceSelector selectClasspathResource(String classpath
 	 * {@code null} or blank
 	 * @param position the position inside the classpath resource; may be {@code null}
 	 * @see #selectClasspathResource(String)
+	 * @see #selectClasspathResources(String...)
 	 * @see #selectClasspathResourceByName(Set)
 	 * @see ClasspathResourceSelector
 	 * @see ClassLoader#getResource(String)
@@ -413,6 +416,45 @@ public static ClasspathResourceSelector selectClasspathResourceByName(Set<? exte
 		return new ClasspathResourceSelector(classpathResources);
 	}
 
+	/**
+	 * Create a {@code ClasspathResourceSelector} for each supplied classpath
+	 * resource name.
+	 *
+	 * @param classpathResourceNames the names of the classpath resource; never
+	 * {@code null} and never containing {@code null} or blank references.
+	 * @since 6.1
+	 * @see #selectClasspathResource(String)
+	 * @see #selectClasspathResources(String...)
+	 * @see ClasspathResourceSelector
+	 */
+	@API(status = EXPERIMENTAL, since = "6.1")
+	public static List<ClasspathResourceSelector> selectClasspathResources(String... classpathResourceNames) {
+		Preconditions.notNull(classpathResourceNames, "classpathResourceNames must not be null");
+		return selectClasspathResources(Arrays.asList(classpathResourceNames));
+	}
+
+	/**
+	 * Create a {@code ClasspathResourceSelector} for each supplied classpath
+	 * resource name.
+	 *
+	 * @param classpathResourceNames the names of the classpath resource; never
+	 * {@code null} and never containing {@code null} or blank references.
+	 * @since 6.1
+	 * @see #selectClasspathResource(String)
+	 * @see #selectClasspathResources(String...)
+	 * @see ClasspathResourceSelector
+	 */
+	@API(status = EXPERIMENTAL, since = "6.1")
+	public static List<ClasspathResourceSelector> selectClasspathResources(List<String> classpathResourceNames) {
+		Preconditions.notNull(classpathResourceNames, "classpathResourceNames must not be null");
+		Preconditions.containsNoBlankElements(classpathResourceNames,
+			"Individual classpathResourceNames must not be null or blank");
+		return classpathResourceNames.stream() //
+				.distinct() //
+				.map(DiscoverySelectors::selectClasspathResource) //
+				.toList();
+	}
+
 	/**
 	 * Create a {@code ModuleSelector} for the supplied module name.
 	 *
@@ -540,7 +582,8 @@ public static ClassSelector selectClass(@Nullable ClassLoader classLoader, Strin
 	 */
 	@API(status = EXPERIMENTAL, since = "6.0")
 	public static List<ClassSelector> selectClasses(Class<?>... classes) {
-		return selectClasses(List.of(classes));
+		Preconditions.notNull(classes, "classes must not be null");
+		return selectClasses(Arrays.asList(classes));
 	}
 
 	/**
@@ -579,7 +622,8 @@ public static List<ClassSelector> selectClasses(List<Class<?>> classes) {
 	 */
 	@API(status = EXPERIMENTAL, since = "6.0")
 	public static List<ClassSelector> selectClassesByName(String... classNames) {
-		return selectClassesByName(List.of(classNames));
+		Preconditions.notNull(classNames, "classNames must not be null");
+		return selectClassesByName(Arrays.asList(classNames));
 	}
 
 	/**
@@ -595,6 +639,7 @@ public static List<ClassSelector> selectClassesByName(String... classNames) {
 	 */
 	@API(status = EXPERIMENTAL, since = "6.0")
 	public static List<ClassSelector> selectClassesByName(List<String> classNames) {
+		Preconditions.notNull(classNames, "classNames must not be null");
 		return selectClassesByName(null, classNames);
 	}
 
@@ -613,7 +658,8 @@ public static List<ClassSelector> selectClassesByName(List<String> classNames) {
 	 */
 	@API(status = EXPERIMENTAL, since = "6.0")
 	public static List<ClassSelector> selectClassesByName(@Nullable ClassLoader classLoader, String... classNames) {
-		return selectClassesByName(classLoader, List.of(classNames));
+		Preconditions.notNull(classNames, "classNames must not be null");
+		return selectClassesByName(classLoader, Arrays.asList(classNames));
 	}
 
 	/**
@@ -631,7 +677,7 @@ public static List<ClassSelector> selectClassesByName(@Nullable ClassLoader clas
 	@API(status = EXPERIMENTAL, since = "6.0")
 	public static List<ClassSelector> selectClassesByName(@Nullable ClassLoader classLoader, List<String> classNames) {
 		Preconditions.notNull(classNames, "classNames must not be null");
-		Preconditions.containsNoNullElements(classNames, "Individual class names must not be null");
+		Preconditions.containsNoBlankElements(classNames, "Individual class names must not be null or blank");
 
 		// @formatter:off
 		return classNames.stream()

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

@@ -14,6 +14,7 @@
 import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.platform.commons.test.PreconditionAssertions.assertPreconditionViolationFor;
 import static org.junit.platform.commons.util.Preconditions.condition;
+import static org.junit.platform.commons.util.Preconditions.containsNoBlankElements;
 import static org.junit.platform.commons.util.Preconditions.containsNoNullElements;
 import static org.junit.platform.commons.util.Preconditions.notBlank;
 import static org.junit.platform.commons.util.Preconditions.notEmpty;
@@ -106,6 +107,32 @@ void notEmptyThrowsForEmptyCollection() {
 		assertPreconditionViolationFor(() -> notEmpty(List.of(), message)).withMessage(message);
 	}
 
+	@Test
+	void containsNoBlankElementsPassesForCollectionThatIsNullOrEmpty() {
+		containsNoBlankElements((List<String>) null, "collection is null");
+		containsNoBlankElements(List.of(), "collection is empty");
+
+		containsNoBlankElements((List<String>) null, () -> "collection is null");
+		containsNoBlankElements(List.of(), () -> "collection is empty");
+	}
+
+	@Test
+	void containsNoBlankElementsPassesForCollectionContainingNonBlankElements() {
+		var input = List.of("a", "b", "c");
+		var output = containsNoBlankElements(input, "message");
+		assertSame(input, output);
+	}
+
+	@Test
+	void containsNoBlankElementsThrowsForCollectionContainingNullElements() {
+		var message = "collection contains blank elements";
+
+		assertPreconditionViolationFor(() -> containsNoBlankElements(singletonList(""), message)) //
+				.withMessage(message);
+		assertPreconditionViolationFor(() -> containsNoBlankElements(singletonList((String) null), message)) //
+				.withMessage(message);
+	}
+
 	@Test
 	void containsNoNullElementsPassesForArrayThatIsNullOrEmpty() {
 		containsNoNullElements((Object[]) null, "array is null");

platform-tests/src/test/java/org/junit/platform/engine/discovery/DiscoverySelectorsTests.java

@@ -11,6 +11,7 @@
 package org.junit.platform.engine.discovery;
 
 import static java.lang.String.join;
+import static java.util.Collections.singletonList;
 import static java.util.Objects.requireNonNull;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.InstanceOfAssertFactories.type;
@@ -25,6 +26,7 @@
 import static org.junit.platform.engine.discovery.DiscoverySelectors.selectClassesByName;
 import static org.junit.platform.engine.discovery.DiscoverySelectors.selectClasspathResource;
 import static org.junit.platform.engine.discovery.DiscoverySelectors.selectClasspathResourceByName;
+import static org.junit.platform.engine.discovery.DiscoverySelectors.selectClasspathResources;
 import static org.junit.platform.engine.discovery.DiscoverySelectors.selectClasspathRoots;
 import static org.junit.platform.engine.discovery.DiscoverySelectors.selectDirectory;
 import static org.junit.platform.engine.discovery.DiscoverySelectors.selectFile;
@@ -298,7 +300,7 @@ class SelectClasspathResourceTests {
 
 		@SuppressWarnings("DataFlowIssue")
 		@Test
-		void selectClasspathResourcesPreconditions() {
+		void selectClasspathResourcePreconditions() {
 			// @formatter:off
 			assertPreconditionViolationFor(() -> selectClasspathResource((String) null));
 			assertPreconditionViolationFor(() -> selectClasspathResource(""));
@@ -317,7 +319,7 @@ void selectClasspathResourcesPreconditions() {
 		}
 
 		@Test
-		void selectIndividualClasspathResources() {
+		void selectIndividualClasspathResource() {
 			// with unnecessary "/" prefix
 			var selector = selectClasspathResource("/foo/bar/spec.xml");
 			assertEquals("foo/bar/spec.xml", selector.getClasspathResourceName());
@@ -328,7 +330,7 @@ void selectIndividualClasspathResources() {
 		}
 
 		@Test
-		void getSelectedClasspathResources() {
+		void getSelectedClasspathResource() {
 			var selector = selectClasspathResource("org/junit/platform/commons/example.resource");
 			var classpathResources = selector.getResources();
 			assertAll(() -> assertThat(classpathResources).hasSize(1), //
@@ -339,7 +341,7 @@ void getSelectedClasspathResources() {
 		}
 
 		@Test
-		void getMissingClasspathResources() {
+		void getMissingClasspathResource() {
 			var selector = selectClasspathResource("org/junit/platform/commons/no-such-example.resource");
 			assertPreconditionViolationFor(selector::getResources);
 		}
@@ -417,6 +419,52 @@ public URI getUri() {
 		}
 	}
 
+	/**
+	 * @since 6.1
+	 */
+	@Nested
+	class SelectClasspathResourcesTests {
+
+		@SuppressWarnings("DataFlowIssue")
+		@Test
+		void selectClasspathResourcesPreconditions() {
+			assertPreconditionViolationFor(() -> selectClasspathResources((String) null));
+			assertPreconditionViolationFor(() -> selectClasspathResources((String[]) null));
+			assertPreconditionViolationFor(() -> selectClasspathResources(""));
+			assertPreconditionViolationFor(() -> selectClasspathResources(singletonList(null)));
+			assertPreconditionViolationFor(() -> selectClasspathResources(singletonList("")));
+		}
+
+		@Test
+		void selectMultipleClasspathResources() {
+			var selectors = selectClasspathResources( //
+				"org/junit/platform/example-a.resource", //
+				"org/junit/platform/example-b.resource" //
+			);
+			assertThat(selectors).extracting(ClasspathResourceSelector::getClasspathResourceName) //
+					.containsExactly( //
+						"org/junit/platform/example-a.resource", //
+						"org/junit/platform/example-b.resource" //
+					);
+		}
+
+		@Test
+		void selectDistinctClasspathResources() {
+			var selectors = selectClasspathResources( //
+				"org/junit/platform/example-a.resource", //
+				"org/junit/platform/example-b.resource", //
+				"org/junit/platform/example-a.resource", //
+				"org/junit/platform/example-c.resource" //
+			);
+			assertThat(selectors).extracting(ClasspathResourceSelector::getClasspathResourceName) //
+					.containsExactly( //
+						"org/junit/platform/example-a.resource", //
+						"org/junit/platform/example-b.resource", //
+						"org/junit/platform/example-c.resource" //
+					);
+		}
+	}
+
 	@Nested
 	class SelectModuleTests {