Allow format specifiers in exception message

Prior to this commit format specifiers in exception messages resulted
in a MissingFormatArgumentException. Now every user-defined string is
treated as an argument itself, effectively preventing a reformatting
of the passed string.

Closes #1600

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

@@ -61,7 +61,7 @@ public void testPlanExecutionStarted(TestPlan testPlan) {
 		frames.push(System.currentTimeMillis());
 
 		long tests = testPlan.countTestIdentifiers(TestIdentifier::isTest);
-		printf(NONE, "Test plan execution started. Number of static tests: ");
+		printf(NONE, "%s", "Test plan execution started. Number of static tests: ");
 		printf(Color.TEST, "%d%n", tests);
 		printf(Color.CONTAINER, "%s%n", theme.root());
 	}
@@ -71,7 +71,7 @@ public void testPlanExecutionFinished(TestPlan testPlan) {
 		frames.pop();
 
 		long tests = testPlan.countTestIdentifiers(TestIdentifier::isTest);
-		printf(NONE, "Test plan execution finished. Number of all tests: ");
+		printf(NONE, "%s", "Test plan execution finished. Number of all tests: ");
 		printf(Color.TEST, "%d%n", tests);
 	}
 
@@ -120,7 +120,7 @@ public void executionSkipped(TestIdentifier testIdentifier, String reason) {
 	public void dynamicTestRegistered(TestIdentifier testIdentifier) {
 		printVerticals(theme.entry());
 		printf(Color.DYNAMIC, " %s", testIdentifier.getDisplayName());
-		printf(NONE, " dynamically registered%n");
+		printf(NONE, "%s", " dynamically registered%n");
 	}
 
 	@Override
@@ -171,7 +171,7 @@ private void printDetail(Color color, String detail, String format, Object... ar
 		String detailFormat = "%9s";
 		// omit detail string if it's empty
 		if (!detail.isEmpty()) {
-			printf(NONE, String.format(detailFormat + ": ", detail));
+			printf(NONE, "%s", String.format(detailFormat + ": ", detail));
 		}
 		// trivial case: at least one arg is given? Let printf do the entire work
 		if (args.length > 0) {
@@ -180,12 +180,12 @@ private void printDetail(Color color, String detail, String format, Object... ar
 		}
 		// still here? Split format into separate lines and indent them from the second line on
 		String[] lines = format.split("\\R");
-		printf(color, lines[0]);
+		printf(color, "%s", lines[0]);
 		if (lines.length > 1) {
 			String delimiter = System.lineSeparator() + verticals + String.format(detailFormat + "    ", "");
 			for (int i = 1; i < lines.length; i++) {
-				printf(NONE, delimiter);
-				printf(color, lines[i]);
+				printf(NONE, "%s", delimiter);
+				printf(color, "%s", lines[i]);
 			}
 		}
 		printf(NONE, "%n");

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

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2015-2018 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
+ *
+ * http://www.eclipse.org/legal/epl-v20.html
+ */
+
+package org.junit.platform.console.tasks;
+
+import static org.junit.jupiter.api.Assertions.assertLinesMatch;
+import static org.junit.platform.engine.TestExecutionResult.failed;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+import org.junit.platform.console.options.Theme;
+import org.junit.platform.engine.UniqueId;
+import org.junit.platform.engine.reporting.ReportEntry;
+import org.junit.platform.engine.test.TestDescriptorStub;
+import org.junit.platform.launcher.TestIdentifier;
+
+/**
+ * @since 1.4
+ */
+class VerboseTreeListenerTests {
+
+	private static final String EOL = System.lineSeparator();
+
+	@Test
+	void executionSkipped() {
+		StringWriter stringWriter = new StringWriter();
+		listener(stringWriter).executionSkipped(newTestIdentifier(), "Test" + EOL + "disabled");
+		String[] lines = lines(stringWriter);
+
+		assertLinesMatch(List.of( //
+			"+-- %c ool test", //
+			"     tags: []", //
+			" uniqueId: [engine:demo-engine]", //
+			"   parent: []", //
+			"   reason: Test", //
+			"             disabled", //
+			"   status: [S] SKIPPED"), List.of(lines));
+	}
+
+	@Test
+	void reportingEntryPublished() {
+		StringWriter stringWriter = new StringWriter();
+		listener(stringWriter).reportingEntryPublished(newTestIdentifier(), ReportEntry.from("foo", "bar"));
+		String[] lines = lines(stringWriter);
+
+		assertLinesMatch(List.of("  reports: ReportEntry \\[timestamp = .+, foo = 'bar'\\]"), List.of(lines));
+	}
+
+	@Test
+	void executionFinishedWithFailure() {
+		StringWriter stringWriter = new StringWriter();
+		listener(stringWriter).executionFinished(newTestIdentifier(), failed(new AssertionError("Boom!")));
+		String[] lines = lines(stringWriter);
+
+		assertLinesMatch(List.of("   caught: java.lang.AssertionError: Boom!", //
+			">> STACKTRACE >>", //
+			" duration: \\d+ ms", //
+			"   status: [X] FAILED"), List.of(lines));
+	}
+
+	@Test
+	void failureMessageWithFormatSpecifier() {
+		StringWriter stringWriter = new StringWriter();
+		listener(stringWriter).executionFinished(newTestIdentifier(), failed(new AssertionError("%crash")));
+		String[] lines = lines(stringWriter);
+
+		assertLinesMatch(List.of("   caught: java.lang.AssertionError: %crash", //
+			">> STACKTRACE >>", //
+			" duration: \\d+ ms", //
+			"   status: [X] FAILED"), List.of(lines));
+	}
+
+	private VerboseTreePrintingListener listener(StringWriter stringWriter) {
+		return new VerboseTreePrintingListener(new PrintWriter(stringWriter), true, 16, Theme.ASCII);
+	}
+
+	private static TestIdentifier newTestIdentifier() {
+		TestDescriptorStub testDescriptor = new TestDescriptorStub(UniqueId.forEngine("demo-engine"), "%c ool test");
+		return TestIdentifier.from(testDescriptor);
+	}
+
+	private String[] lines(StringWriter stringWriter) {
+		return stringWriter.toString().split(EOL);
+	}
+
+}