Log nonexistent classpath roots in Console Launcher

To help diagnosing potentially invalid invocations, the Console Launcher
now logs warnings for nonexistent classpath roots added via
`--classpath` or `--scan-classpath` rather than silently ignoring them.

Resolves #4772.

Author: currenjin

documentation/src/docs/asciidoc/release-notes/release-notes-6.0.0-RC1.adoc

@@ -37,6 +37,9 @@ repository on GitHub.
   names in JUnit Jupiter, `@SuiteDisplayName`, and any other test engines that subclass
   `AbstractTestDescriptor`. Please refer to the
   <<../user-guide/index.adoc#writing-tests-display-names, User Guide>> for details.
+* To help diagnosing potentially invalid invocations, the Console Launcher now logs
+  warnings for nonexistent classpath roots added via `--classpath` or `--scan-classpath`
+  rather than silently ignoring them.
 
 
 [[release-notes-6.0.0-RC1-junit-jupiter]]

junit-platform-console/src/main/java/org/junit/platform/console/tasks/DiscoveryRequestCreator.java

@@ -24,14 +24,18 @@
 import static org.junit.platform.launcher.TagFilter.includeTags;
 import static org.junit.platform.launcher.core.LauncherDiscoveryRequestBuilder.request;
 
+import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Objects;
 import java.util.Set;
 import java.util.regex.Pattern;
 import java.util.stream.Stream;
 
+import org.junit.platform.commons.logging.Logger;
+import org.junit.platform.commons.logging.LoggerFactory;
 import org.junit.platform.commons.util.ModuleUtils;
 import org.junit.platform.commons.util.Preconditions;
 import org.junit.platform.commons.util.ReflectionUtils;
@@ -49,6 +53,8 @@
  */
 class DiscoveryRequestCreator {
 
+	private static final Logger logger = LoggerFactory.getLogger(DiscoveryRequestCreator.class);
+
 	static LauncherDiscoveryRequestBuilder toDiscoveryRequestBuilder(TestDiscoveryOptions options) {
 		LauncherDiscoveryRequestBuilder requestBuilder = request();
 		List<? extends DiscoverySelector> selectors = createDiscoverySelectors(options);
@@ -77,7 +83,7 @@ private static List<? extends DiscoverySelector> createDiscoverySelectors(TestDi
 	}
 
 	private static List<ClasspathRootSelector> createClasspathRootSelectors(TestDiscoveryOptions options) {
-		Set<Path> classpathRoots = determineClasspathRoots(options);
+		Set<Path> classpathRoots = validateAndLogInvalidRoots(determineClasspathRoots(options));
 		return selectClasspathRoots(classpathRoots);
 	}
 
@@ -86,12 +92,31 @@ private static Set<Path> determineClasspathRoots(TestDiscoveryOptions options) {
 			() -> "No classpath entries selected");
 		if (selectedClasspathEntries.isEmpty()) {
 			Set<Path> rootDirs = new LinkedHashSet<>(ReflectionUtils.getAllClasspathRootDirectories());
-			rootDirs.addAll(options.getExistingAdditionalClasspathEntries());
+			rootDirs.addAll(options.getAdditionalClasspathEntries());
 			return rootDirs;
 		}
 		return new LinkedHashSet<>(selectedClasspathEntries);
 	}
 
+	private static Set<Path> validateAndLogInvalidRoots(Set<Path> roots) {
+		LinkedHashSet<Path> valid = new LinkedHashSet<>();
+		HashSet<Path> seen = new HashSet<>();
+
+		for (Path root : roots) {
+			if (!seen.add(root)) {
+				continue;
+			}
+			if (Files.exists(root)) {
+				valid.add(root);
+			}
+			else {
+				logger.warn(() -> "Ignoring nonexistent classpath root: %s".formatted(root));
+			}
+		}
+
+		return valid;
+	}
+
 	private static void addFilters(LauncherDiscoveryRequestBuilder requestBuilder, TestDiscoveryOptions options,
 			List<? extends DiscoverySelector> selectors) {
 		requestBuilder.filters(includedClassNamePatterns(options, selectors));

platform-tests/src/test/java/org/junit/platform/console/tasks/DiscoveryRequestCreatorTests.java

@@ -31,10 +31,13 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.logging.LogRecord;
 import java.util.stream.Stream;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.fixtures.TrackLogRecords;
 import org.junit.platform.commons.PreconditionViolationException;
+import org.junit.platform.commons.logging.LogRecordListener;
 import org.junit.platform.console.options.TestDiscoveryOptions;
 import org.junit.platform.engine.Filter;
 import org.junit.platform.engine.UniqueId;
@@ -372,6 +375,36 @@ void convertsConfigurationParametersResources() {
 		assertThat(configurationParameters.get("com.example.prop.second")).contains("second value");
 	}
 
+	@Test
+	void logsInvalidSearchPathRoots(@TrackLogRecords LogRecordListener listener) {
+		var opts = new TestDiscoveryOptions();
+		opts.setScanClasspath(true);
+		var missingPath = Path.of("/does/not/exist");
+		opts.setSelectedClasspathEntries(List.of(missingPath));
+
+		DiscoveryRequestCreator.toDiscoveryRequestBuilder(opts);
+
+		assertThat(listener.stream(DiscoveryRequestCreator.class)) //
+				.map(LogRecord::getMessage) //
+				.filteredOn(message -> message.contains(missingPath.toString())) //
+				.hasSize(1);
+	}
+
+	@Test
+	void logsInvalidAdditionalClasspathRoots(@TrackLogRecords LogRecordListener listener) {
+		var opts = new TestDiscoveryOptions();
+		opts.setScanClasspath(true);
+		var missingPath = Path.of("/also/does/not/exist");
+		opts.setAdditionalClasspathEntries(List.of(missingPath));
+
+		DiscoveryRequestCreator.toDiscoveryRequestBuilder(opts);
+
+		assertThat(listener.stream(DiscoveryRequestCreator.class)) //
+				.map(LogRecord::getMessage) //
+				.filteredOn(message -> message.contains(missingPath.toString())) //
+				.hasSize(1);
+	}
+
 	private LauncherDiscoveryRequest convert() {
 		return DiscoveryRequestCreator.toDiscoveryRequestBuilder(options).build();
 	}

platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/StandaloneTests.java

@@ -405,6 +405,7 @@ void execute(@FilePrefix("console-launcher") OutputFiles outputFiles) throws Exc
 				.addArguments("-enableassertions") //
 				.addArguments("-Djava.util.logging.config.file=logging.properties") //
 				.addArguments("-Djunit.platform.launcher.interceptors.enabled=true") //
+				.addArguments("-Duser.language=en", "-Duser.country=US") //
 				.addArguments("-jar", MavenRepo.jar("junit-platform-console-standalone").toString()) //
 				.addArguments("execute") //
 				.addArguments("--scan-class-path") //
@@ -517,6 +518,7 @@ void executeWithJarredTestClasses(@FilePrefix("jar") OutputFiles jarOutputFiles,
 				.addArguments("-enableassertions") //
 				.addArguments("-Djava.util.logging.config.file=logging.properties") //
 				.addArguments("-Djunit.platform.launcher.interceptors.enabled=true") //
+				.addArguments("-Duser.language=en", "-Duser.country=US") //
 				.addArguments("-jar", MavenRepo.jar("junit-platform-console-standalone").toString()) //
 				.addArguments("execute") //
 				.addArguments("--scan-class-path") //