Introduce support for converting from a URI of the form method:<FQMN> to a MethodSource

documentation/src/docs/asciidoc/release-notes/release-notes-5.5.0-RC1.adoc

@@ -79,6 +79,8 @@ on GitHub.
 * New `InvocationInterceptor` extension API (see
   <<../user-guide/index.adoc#extensions-intercepting-invocations, User Guide>> for
   details).
+* Added support for method URIs, e.g. `method:org.junit.Foo#bar()`, to `DynamicContainer`
+  and `DynamicTest` factory methods.
 
 
 [[release-notes-5.5.0-RC1-junit-vintage]]

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/descriptor/MethodSourceSupport.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2015-2019 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * https://www.eclipse.org/legal/epl-v20.html
+ */
+
+package org.junit.jupiter.engine.descriptor;
+
+import java.net.URI;
+
+import org.junit.platform.commons.util.Preconditions;
+import org.junit.platform.commons.util.ReflectionUtils;
+import org.junit.platform.engine.discovery.DiscoverySelectors;
+import org.junit.platform.engine.discovery.MethodSelector;
+import org.junit.platform.engine.support.descriptor.MethodSource;
+
+/**
+ * Jupiter internal support for creating {@link MethodSource} from {@link URI}.
+ *
+ * @since 5.5
+ * @see MethodSource
+ * @see MethodSelector
+ */
+class MethodSourceSupport {
+
+	static final String METHOD_SCHEME = "method";
+
+	/**
+	 * Create a new {@code MethodSource} from the supplied {@link URI}.
+	 *
+	 * <p>The supplied {@link URI} should be of the form {@code method:<FQMN>}
+	 * where FQMN is the fully qualified method name. See
+	 * {@link DiscoverySelectors#selectMethod(String)} for the supported formats.
+	 *
+	 * <p></p>The {@link URI#getSchemeSpecificPart() scheme-specific part}
+	 * component of the {@code URI} will be used as fully qualified class name.
+	 * The {@linkplain URI#getFragment() fragment} component of the {@code URI}
+	 * will be used to retrieve the method name and method parameter types.
+	 *
+	 * @param uri the {@code URI} for the method; never {@code null}
+	 * @return a new {@code MethodSource}; never {@code null}
+	 * @since 5.5
+	 * @see #METHOD_SCHEME
+	 * @see DiscoverySelectors#selectMethod(String)
+	 */
+	static MethodSource from(URI uri) {
+		Preconditions.notNull(uri, "URI must not be null");
+		Preconditions.condition(METHOD_SCHEME.equals(uri.getScheme()),
+			() -> "URI [" + uri + "] must have [" + METHOD_SCHEME + "] scheme");
+		String schemeSpecificPart = Preconditions.notNull(uri.getSchemeSpecificPart(),
+			() -> "Invalid method URI (scheme-specific part must not be null). Please consult the Javadoc of "
+					+ DiscoverySelectors.class.getName()
+					+ "#selectMethod(String) for details on the supported formats.");
+		String fragment = Preconditions.notNull(uri.getFragment(),
+			() -> "Invalid method URI (fragment must not be null). Please consult the Javadoc of "
+					+ DiscoverySelectors.class.getName()
+					+ "#selectMethod(String) for details on the supported formats.");
+
+		String fullyQualifiedMethodName = schemeSpecificPart + "#" + fragment;
+		String[] methodSpec = ReflectionUtils.parseFullyQualifiedMethodName(fullyQualifiedMethodName);
+		return MethodSource.from(methodSpec[0], methodSpec[1], methodSpec[2]);
+	}
+}

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/descriptor/TestFactoryTestDescriptor.java

@@ -11,6 +11,7 @@
 package org.junit.jupiter.engine.descriptor;
 
 import static org.apiguardian.api.API.Status.INTERNAL;
+import static org.junit.jupiter.engine.descriptor.MethodSourceSupport.METHOD_SCHEME;
 import static org.junit.platform.engine.support.descriptor.ClasspathResourceSource.CLASSPATH_SCHEME;
 
 import java.lang.reflect.Method;
@@ -165,7 +166,13 @@ static Optional<JupiterTestDescriptor> createDynamicDescriptor(JupiterTestDescri
 	 */
 	static TestSource fromUri(URI uri) {
 		Preconditions.notNull(uri, "URI must not be null");
-		return CLASSPATH_SCHEME.equals(uri.getScheme()) ? ClasspathResourceSource.from(uri) : UriSource.from(uri);
+		if (CLASSPATH_SCHEME.equals(uri.getScheme())) {
+			return ClasspathResourceSource.from(uri);
+		}
+		if (METHOD_SCHEME.equals(uri.getScheme())) {
+			return MethodSourceSupport.from(uri);
+		}
+		return UriSource.from(uri);
 	}
 
 	/**

junit-jupiter-engine/src/test/java/org/junit/jupiter/engine/descriptor/TestFactoryTestDescriptorTests.java

@@ -37,6 +37,7 @@
 import org.junit.platform.engine.support.descriptor.DirectorySource;
 import org.junit.platform.engine.support.descriptor.FilePosition;
 import org.junit.platform.engine.support.descriptor.FileSource;
+import org.junit.platform.engine.support.descriptor.MethodSource;
 import org.junit.platform.engine.support.descriptor.UriSource;
 import org.junit.platform.engine.support.hierarchical.Node;
 import org.junit.platform.engine.support.hierarchical.OpenTest4JAwareThrowableCollector;
@@ -108,6 +109,18 @@ void defaultUriSourceFromUri() {
 			assertThat(source.getUri()).isEqualTo(uri);
 		}
 
+		@Test
+		void methodSourceFromUri() {
+			URI uri = URI.create("method:org.junit.Foo#bar(java.lang.String,%20java.lang.String[])");
+			TestSource testSource = TestFactoryTestDescriptor.fromUri(uri);
+
+			assertThat(testSource).isInstanceOf(MethodSource.class);
+			assertThat(testSource.getClass().getSimpleName()).isEqualTo("MethodSource");
+			MethodSource source = (MethodSource) testSource;
+			assertThat(source.getClassName()).isEqualTo("org.junit.Foo");
+			assertThat(source.getMethodName()).isEqualTo("bar");
+			assertThat(source.getMethodParameterTypes()).isEqualTo("java.lang.String, java.lang.String[]");
+		}
 	}
 
 	@Nested