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

… to a MethodSource

Introduce support for converting from a URI of the form method:<FQMN> to a MethodSource, where FQMN is the fully qualified method name. See the Javadoc for DiscoverySelectors.selectMethod(String) for the supported formats for a FQMN. Closes junit-teamgh-1850

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

@@ -0,0 +1,23 @@
+package org.junit.jupiter.engine.descriptor;
+
+import org.junit.platform.commons.util.Preconditions;
+import org.junit.platform.commons.util.ReflectionUtils;
+import org.junit.platform.engine.support.descriptor.MethodSource;
+
+import java.net.URI;
+import java.util.Optional;
+
+class MethodSourceUtils {
+
+	static final String METHOD_SCHEME = "method";
+
+	static MethodSource fromUri(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 fragment = Optional.ofNullable(uri.getFragment()).orElseThrow(() -> new IllegalArgumentException("Invalid method URI"));
+		String fullyQualifiedMethodName = uri.getSchemeSpecificPart() + "#" + fragment;
+		String[] methodSpecs = ReflectionUtils.parseFullyQualifiedMethodName(fullyQualifiedMethodName);
+		return MethodSource.from(methodSpecs[0], methodSpecs[1], methodSpecs[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.MethodSourceUtils.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);
+		} else if (METHOD_SCHEME.equals(uri.getScheme())) {
+			return MethodSourceUtils.fromUri(uri);
+		} else {
+			return UriSource.from(uri);
+		}
 	}
 
 	/**

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

@@ -16,8 +16,10 @@
 import static org.mockito.Mockito.when;
 
 import java.io.File;
+import java.io.UnsupportedEncodingException;
 import java.lang.reflect.Method;
 import java.net.URI;
+import java.net.URLEncoder;
 import java.util.Optional;
 import java.util.stream.Stream;
 
@@ -31,13 +33,10 @@
 import org.junit.jupiter.engine.config.JupiterConfiguration;
 import org.junit.jupiter.engine.execution.JupiterEngineExecutionContext;
 import org.junit.jupiter.engine.extension.ExtensionRegistry;
+import org.junit.platform.commons.util.ReflectionUtils;
 import org.junit.platform.engine.TestSource;
 import org.junit.platform.engine.UniqueId;
-import org.junit.platform.engine.support.descriptor.ClasspathResourceSource;
-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.UriSource;
+import org.junit.platform.engine.support.descriptor.*;
 import org.junit.platform.engine.support.hierarchical.Node;
 import org.junit.platform.engine.support.hierarchical.OpenTest4JAwareThrowableCollector;
 
@@ -108,6 +107,19 @@ void defaultUriSourceFromUri() {
 			assertThat(source.getUri()).isEqualTo(uri);
 		}
 
+		@Test
+		void methodSourceFromUri() {
+			String methodUri = "method:org.junit.Foo#bar(java.lang.String,%20java.lang.String[])";
+			URI uri = URI.create(methodUri);
+			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