Issue: junit-team#3139 part 1

Tasks completed:
1. Locate ConsoleLauncher output
2. Check if actual and expected of AssertionFailedError are both type of CharSequence
To do list:
1. Add diff function dependency
2. Using diff to generate the output desired

Issue: junit-team#3139

Author: XuJ321

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

@@ -36,6 +36,9 @@
 import org.junit.platform.launcher.listeners.SummaryGeneratingListener;
 import org.junit.platform.launcher.listeners.TestExecutionSummary;
 import org.junit.platform.reporting.legacy.xml.LegacyXmlReportGeneratingListener;
+//for console output of diff
+import org.opentest4j.AssertionFailedError;
+import org.opentest4j.ValueWrapper;
 
 /**
  * @since 1.0
@@ -180,11 +183,34 @@ private Optional<TestExecutionListener> createXmlWritingListener(PrintWriter out
 	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())) {
+			//adding diff code here
+			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)) {
+						out.printf("Expected %s\n", expected.getStringRepresentation());
+						out.printf("Actual   %s\n", actual.getStringRepresentation());
+						//out.printf("Diff     %s", calculateDiff(expected, actual));
+					}
+
+				}
+			});
+
+			summary.getFailures();
 			summary.printFailuresTo(out);
 		}
 		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);