Output diff of expected and actual values in ConsoleLauncher

documentation/src/docs/asciidoc/release-notes/release-notes-5.12.0-M1.adoc

@@ -4,6 +4,7 @@
 *Date of Release:* ❓
 
 *Scope:* ❓
+* `ConsoleLauncher` output shows extra diff message for failed assertions on two `CharSequence` objects
 
 For a complete list of all _closed_ issues and pull requests for this release, consult the
 link:{junit5-repo}+/milestone/75?closed=1+[5.12.0-M1] milestone page in the

gradle/libs.versions.toml

@@ -44,6 +44,7 @@ jfrunit = { module = "org.moditect.jfrunit:jfrunit-core", version = "1.0.0.Alpha
 jimfs = { module = "com.google.jimfs:jimfs", version = "1.3.0" }
 jmh-core = { module = "org.openjdk.jmh:jmh-core", version.ref = "jmh" }
 jmh-generator-annprocess = { module = "org.openjdk.jmh:jmh-generator-annprocess", version.ref = "jmh" }
+java-diff-utils = { module = "io.github.java-diff-utils:java-diff-utils", version = "4.12" }
 joox = { module = "org.jooq:joox", version = "2.0.1" }
 jte = { module = "gg.jte:jte", version = "3.1.12" }
 junit4 = { module = "junit:junit", version = { require = "[4.12,)", prefer = "4.13.2" } }

junit-platform-console/junit-platform-console.gradle.kts

@@ -16,6 +16,8 @@ dependencies {
 
 	compileOnly(libs.openTestReporting.events)
 
+	implementation(libs.java.diff.utils)
+
 	shadowed(libs.picocli)
 
 	osgiVerification(projects.junitJupiterEngine)
@@ -28,7 +30,9 @@ tasks {
 			"--add-modules", "org.opentest4j.reporting.events",
 			"--add-reads", "${project.projects.junitPlatformReporting.dependencyProject.javaModuleName}=org.opentest4j.reporting.events",
 			"--add-modules", "info.picocli",
-			"--add-reads", "${javaModuleName}=info.picocli"
+			"--add-reads", "${javaModuleName}=info.picocli",
+			"--add-modules", "io.github.javadiffutils",
+			"--add-reads", "${javaModuleName}=io.github.javadiffutils"
 		))
 	}
 	shadowJar {

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

@@ -36,6 +36,8 @@
 import org.junit.platform.launcher.listeners.SummaryGeneratingListener;
 import org.junit.platform.launcher.listeners.TestExecutionSummary;
 import org.junit.platform.reporting.legacy.xml.LegacyXmlReportGeneratingListener;
+import org.opentest4j.AssertionFailedError;
+import org.opentest4j.ValueWrapper;
 
 /**
  * @since 1.0
@@ -47,6 +49,8 @@ public class ConsoleTestExecutor {
 	private final TestConsoleOutputOptions outputOptions;
 	private final Supplier<Launcher> launcherSupplier;
 
+	private TestPlan testPlanListeners;
+
 	public ConsoleTestExecutor(TestDiscoveryOptions discoveryOptions, TestConsoleOutputOptions outputOptions) {
 		this(discoveryOptions, outputOptions, LauncherFactory::create);
 	}
@@ -77,7 +81,6 @@ private void discoverTests(PrintWriter out) {
 
 		LauncherDiscoveryRequest discoveryRequest = new DiscoveryRequestCreator().toDiscoveryRequest(discoveryOptions);
 		TestPlan testPlan = launcher.discover(discoveryRequest);
-
 		commandLineTestPrinter.ifPresent(printer -> printer.listTests(testPlan));
 		if (outputOptions.getDetails() != Details.NONE) {
 			printFoundTestsSummary(out, testPlan);
@@ -97,12 +100,12 @@ private static void printFoundTestsSummary(PrintWriter out, TestPlan testPlan) {
 	private TestExecutionSummary executeTests(PrintWriter out, Optional<Path> reportsDir) {
 		Launcher launcher = launcherSupplier.get();
 		SummaryGeneratingListener summaryListener = registerListeners(out, reportsDir, launcher);
-
 		LauncherDiscoveryRequest discoveryRequest = new DiscoveryRequestCreator().toDiscoveryRequest(discoveryOptions);
 		launcher.execute(discoveryRequest);
-
 		TestExecutionSummary summary = summaryListener.getSummary();
 		if (summary.getTotalFailureCount() > 0 || outputOptions.getDetails() != Details.NONE) {
+			//get testPlan from summaryListener
+			testPlanListeners = summaryListener.getTestPlan();
 			printSummary(summary, out);
 		}
 
@@ -181,10 +184,30 @@ private void printSummary(TestExecutionSummary summary, PrintWriter out) {
 		// Otherwise the failures have already been printed in detail
 		if (EnumSet.of(Details.NONE, Details.SUMMARY, Details.TREE).contains(outputOptions.getDetails())) {
 			summary.printFailuresTo(out);
+			//adding diff code here
+			out.printf("%nDiffs (Markdown):%n");
+			summary.getFailures().forEach(failure -> {
+				//get AssertionFailedError
+				if (failure.getException() instanceof AssertionFailedError) {
+					AssertionFailedError assertionFailedError = (AssertionFailedError) failure.getException();
+					ValueWrapper expected = assertionFailedError.getExpected();
+					ValueWrapper actual = assertionFailedError.getActual();
+					//apply diff function
+					if (isCharSequence(expected) && isCharSequence(actual)) {
+						new DiffPrinter(testPlanListeners).printDiff(out, expected.getStringRepresentation(),
+							actual.getStringRepresentation(), failure.getTestIdentifier());
+					}
+
+				}
+			});
 		}
 		summary.printTo(out);
 	}
 
+	private boolean isCharSequence(ValueWrapper value) {
+		return value != null && CharSequence.class.isAssignableFrom(value.getType());
+	}
+
 	@FunctionalInterface
 	public interface Factory {
 		ConsoleTestExecutor create(TestDiscoveryOptions discoveryOptions, TestConsoleOutputOptions outputOptions);

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

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2015-2024 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.platform.console.tasks;
+
+import static java.lang.String.join;
+
+import java.io.PrintWriter;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import com.github.difflib.text.DiffRow;
+import com.github.difflib.text.DiffRowGenerator;
+
+import org.junit.platform.launcher.TestIdentifier;
+import org.junit.platform.launcher.TestPlan;
+
+/**
+ * class provide access to printDiff function
+ */
+class DiffPrinter {
+	private final TestPlan testPlan;
+
+	public DiffPrinter(TestPlan testPlan) {
+		this.testPlan = testPlan;
+	}
+
+	//print the difference of two print to out
+	void printDiff(PrintWriter out, String expected, String actual, TestIdentifier testIdentifier) {
+		out.printf("  %s:", describeTest(testIdentifier));
+		boolean inlineDiffByWordFlag = false;
+		if (expected.contains(" ") || actual.contains(" ")) {
+			inlineDiffByWordFlag = true;
+		}
+		DiffRowGenerator generator = DiffRowGenerator.create().showInlineDiffs(true).inlineDiffByWord(
+			inlineDiffByWordFlag).oldTag(f -> "~~").newTag(f -> "**").build();
+		List<DiffRow> rows = generator.generateDiffRows(Arrays.asList(expected), Arrays.asList(actual));
+		out.println();
+		out.println("    | expected | actual |");
+		out.println("    | -------- | ------ |");
+		for (DiffRow row : rows) {
+			out.printf("    | %s | %s |", row.getOldLine(), row.getNewLine());
+			out.println();
+		}
+	}
+
+	private String describeTest(TestIdentifier testIdentifier) {
+		List<String> descriptionParts = new ArrayList<>();
+		collectTestDescription(testIdentifier, descriptionParts);
+		return join(":", descriptionParts);
+	}
+
+	private void collectTestDescription(TestIdentifier identifier, List<String> descriptionParts) {
+		descriptionParts.add(0, identifier.getDisplayName());
+		testPlan.getParent(identifier).ifPresent(parent -> collectTestDescription(parent, descriptionParts));
+	}
+}

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

@@ -79,6 +79,7 @@ private void printlnTestDescriptor(Style style, String message, TestIdentifier t
 
 	private void printlnException(Style style, Throwable throwable) {
 		printlnMessage(style, "Exception", ExceptionUtils.readStackTrace(throwable));
+		//add diff here
 	}
 
 	private void printlnMessage(Style style, String message, String detail) {

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

@@ -97,6 +97,7 @@ public void executionStarted(TestIdentifier testIdentifier) {
 	@Override
 	public void executionFinished(TestIdentifier testIdentifier, TestExecutionResult testExecutionResult) {
 		testExecutionResult.getThrowable().ifPresent(t -> printDetail(Style.FAILED, "caught", readStackTrace(t)));
+		//add diff here
 		if (testIdentifier.isContainer()) {
 			Long creationMillis = frames.pop();
 			printVerticals(theme.end());

junit-platform-console/src/module/org.junit.platform.console/module-info.java

@@ -21,5 +21,6 @@
 	requires org.junit.platform.launcher;
 	requires org.junit.platform.reporting;
 
+
 	provides java.util.spi.ToolProvider with org.junit.platform.console.ConsoleLauncherToolProvider;
 }

junit-platform-launcher/src/main/java/org/junit/platform/launcher/listeners/SummaryGeneratingListener.java

@@ -46,6 +46,13 @@ public TestExecutionSummary getSummary() {
 		return this.summary;
 	}
 
+	/**
+	 * Get the testPlan of this listener.
+	 */
+	public TestPlan getTestPlan() {
+		return testPlan;
+	}
+
 	@Override
 	public void testPlanExecutionStarted(TestPlan testPlan) {
 		this.testPlan = testPlan;