Write captured output to dedicated XML elements

If capturing output to `System.out`/`System.err` is enabled, it is now
written into the `system-out`/`system-err` XML elements and excluded
from the output for other report entries, if any.

In addition, this commit slightly revises the existing output to
`system-out` elements:

 - Now they are always written using CDATA sections.
 - The non standard unique-id/display-name `system-out` element always
   comes first.
 - If there are normal report entries, another `system-out` element is
   written next.
 - If there was output captured to `System.out`, another `system-out`
   element is written and always comes last.

Resolves #780.

Author: marcphilipp

documentation/src/docs/asciidoc/release-notes/release-notes-5.3.0-RC1.adoc

@@ -31,6 +31,9 @@ on GitHub.
   present as an interface `default` method.
 * A `ClasspathResourceSource` can now be created from a `URI` via the new `from(URI)`
   static factory method if the `URI` uses the `classpath` scheme.
+* If the new experimental feature is enabled, captured output to `System.out` and
+  `System.err` is now written to the dedicated `system-out` and `system-err` elements,
+  respectively, in the XML report generated by `ConsoleLauncher`.
 
 
 [[release-notes-5.3.0-RC1-junit-jupiter]]

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

@@ -17,14 +17,19 @@
 import static org.junit.platform.commons.util.StringUtils.isNotBlank;
 import static org.junit.platform.console.tasks.XmlReportData.isFailure;
 import static org.junit.platform.engine.TestExecutionResult.Status.FAILED;
+import static org.junit.platform.launcher.LauncherConstants.STDERR_REPORT_ENTRY_KEY;
+import static org.junit.platform.launcher.LauncherConstants.STDOUT_REPORT_ENTRY_KEY;
 
 import java.io.Writer;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.text.NumberFormat;
 import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 import java.util.Optional;
 import java.util.Properties;
 import java.util.TreeSet;
@@ -97,7 +102,7 @@ private void writeTestsuite(TestIdentifier testIdentifier, List<TestIdentifier>
 			writeTestcase(test, numberFormat, writer);
 		}
 
-		writeNonStandardAttributesToSystemOutElement(testIdentifier, writer);
+		writeOutputElement("system-out", formatNonStandardAttributesAsString(testIdentifier), writer);
 
 		writer.writeEndElement();
 		newLine(writer);
@@ -146,8 +151,13 @@ private void writeTestcase(TestIdentifier testIdentifier, NumberFormat numberFor
 		newLine(writer);
 
 		writeSkippedOrErrorOrFailureElement(testIdentifier, writer);
-		writeReportEntriesToSystemOutElement(testIdentifier, writer);
-		writeNonStandardAttributesToSystemOutElement(testIdentifier, writer);
+
+		List<String> systemOutElements = new ArrayList<>();
+		List<String> systemErrElements = new ArrayList<>();
+		systemOutElements.add(formatNonStandardAttributesAsString(testIdentifier));
+		collectReportEntries(testIdentifier, systemOutElements, systemErrElements);
+		writeOutputElements("system-out", systemOutElements, writer);
+		writeOutputElements("system-err", systemErrElements, writer);
 
 		writer.writeEndElement();
 		newLine(writer);
@@ -211,28 +221,41 @@ private void writeFailureAttributesAndContent(Throwable throwable, XMLStreamWrit
 		writeCDataSafely(writer, readStackTrace(throwable));
 	}
 
-	private void writeReportEntriesToSystemOutElement(TestIdentifier testIdentifier, XMLStreamWriter writer)
-			throws XMLStreamException {
-
+	private void collectReportEntries(TestIdentifier testIdentifier, List<String> systemOutElements,
+			List<String> systemErrElements) {
 		List<ReportEntry> entries = this.reportData.getReportEntries(testIdentifier);
 		if (!entries.isEmpty()) {
-			writer.writeStartElement("system-out");
-			newLine(writer);
+			List<String> systemOutElementsForCapturedOutput = new ArrayList<>();
+			StringBuilder formattedReportEntries = new StringBuilder();
 			for (int i = 0; i < entries.size(); i++) {
-				writer.writeCharacters(buildReportEntryDescription(entries.get(i), i + 1));
+				ReportEntry reportEntry = entries.get(i);
+				Map<String, String> keyValuePairs = new LinkedHashMap<>(reportEntry.getKeyValuePairs());
+				removeIfPresentAndAddAsSeparateElement(keyValuePairs, STDOUT_REPORT_ENTRY_KEY,
+					systemOutElementsForCapturedOutput);
+				removeIfPresentAndAddAsSeparateElement(keyValuePairs, STDERR_REPORT_ENTRY_KEY, systemErrElements);
+				if (!keyValuePairs.isEmpty()) {
+					buildReportEntryDescription(reportEntry.getTimestamp(), keyValuePairs, i + 1,
+						formattedReportEntries);
+				}
 			}
-			writer.writeEndElement();
-			newLine(writer);
+			systemOutElements.add(formattedReportEntries.toString().trim());
+			systemOutElements.addAll(systemOutElementsForCapturedOutput);
 		}
 	}
 
-	private String buildReportEntryDescription(ReportEntry reportEntry, int entryNumber) {
-		StringBuilder builder = new StringBuilder(format("Report Entry #{0} (timestamp: {1})\n", entryNumber,
-			ISO_LOCAL_DATE_TIME.format(reportEntry.getTimestamp())));
-
-		reportEntry.getKeyValuePairs().forEach((key, value) -> builder.append(format("\t- {0}: {1}\n", key, value)));
+	private void removeIfPresentAndAddAsSeparateElement(Map<String, String> keyValuePairs, String key,
+			List<String> elements) {
+		String value = keyValuePairs.remove(key);
+		if (value != null) {
+			elements.add(value);
+		}
+	}
 
-		return builder.toString();
+	private void buildReportEntryDescription(LocalDateTime timestamp, Map<String, String> keyValuePairs,
+			int entryNumber, StringBuilder result) {
+		result.append(
+			format("Report Entry #{0} (timestamp: {1})\n", entryNumber, ISO_LOCAL_DATE_TIME.format(timestamp)));
+		keyValuePairs.forEach((key, value) -> result.append(format("\t- {0}: {1}\n", key, value)));
 	}
 
 	private String getTime(TestIdentifier testIdentifier, NumberFormat numberFormat) {
@@ -252,14 +275,22 @@ private LocalDateTime getCurrentDateTime() {
 		return LocalDateTime.now(this.reportData.getClock()).withNano(0);
 	}
 
-	private void writeNonStandardAttributesToSystemOutElement(TestIdentifier testIdentifier, XMLStreamWriter writer)
-			throws XMLStreamException {
+	private String formatNonStandardAttributesAsString(TestIdentifier testIdentifier) {
+		return "unique-id: " + testIdentifier.getUniqueId() //
+				+ "\ndisplay-name: " + testIdentifier.getDisplayName();
+	}
 
-		String cData = "\nunique-id: " + testIdentifier.getUniqueId() //
-				+ "\ndisplay-name: " + testIdentifier.getDisplayName() + "\n";
+	private void writeOutputElements(String elementName, List<String> elements, XMLStreamWriter writer)
+			throws XMLStreamException {
+		for (String content : elements) {
+			writeOutputElement(elementName, content, writer);
+		}
+	}
 
-		writer.writeStartElement("system-out");
-		writeCDataSafely(writer, cData);
+	private void writeOutputElement(String elementName, String content, XMLStreamWriter writer)
+			throws XMLStreamException {
+		writer.writeStartElement(elementName);
+		writeCDataSafely(writer, "\n" + content + "\n");
 		writer.writeEndElement();
 		newLine(writer);
 	}

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

@@ -16,9 +16,12 @@
 import static org.junit.platform.console.tasks.XmlReportAssertions.assertValidAccordingToJenkinsSchema;
 import static org.junit.platform.engine.TestExecutionResult.failed;
 import static org.junit.platform.engine.TestExecutionResult.successful;
+import static org.junit.platform.launcher.LauncherConstants.STDERR_REPORT_ENTRY_KEY;
+import static org.junit.platform.launcher.LauncherConstants.STDOUT_REPORT_ENTRY_KEY;
 
 import java.io.StringWriter;
 import java.time.Clock;
+import java.util.Map;
 
 import org.junit.jupiter.api.Test;
 import org.junit.platform.engine.UniqueId;
@@ -71,12 +74,54 @@ void writesReportEntry() throws Exception {
 		assertThat(content)
 			.containsSubsequence(
 				"<system-out>",
-				"Report Entry #1 (timestamp: ",
-				"- myKey: myValue",
+					"Report Entry #1 (timestamp: ",
+					"- myKey: myValue",
 				"</system-out>");
 		//@formatter:on
 	}
 
+	@Test
+	void writesCapturedOutput() throws Exception {
+		UniqueId uniqueId = engineDescriptor.getUniqueId().append("test", "test");
+		TestDescriptorStub testDescriptor = new TestDescriptorStub(uniqueId, "successfulTest");
+		engineDescriptor.addChild(testDescriptor);
+		TestPlan testPlan = TestPlan.from(singleton(engineDescriptor));
+
+		XmlReportData reportData = new XmlReportData(testPlan, Clock.systemDefaultZone());
+		ReportEntry reportEntry = ReportEntry.from(Map.of( //
+			STDOUT_REPORT_ENTRY_KEY, "normal output", //
+			STDERR_REPORT_ENTRY_KEY, "error output", //
+			"foo", "bar"));
+		reportData.addReportEntry(TestIdentifier.from(testDescriptor), reportEntry);
+		reportData.addReportEntry(TestIdentifier.from(testDescriptor), ReportEntry.from(Map.of("baz", "qux")));
+		reportData.markFinished(testPlan.getTestIdentifier(uniqueId.toString()), successful());
+
+		String content = writeXmlReport(testPlan, reportData);
+
+		assertValidAccordingToJenkinsSchema(content);
+		//@formatter:off
+		assertThat(content)
+			.containsSubsequence(
+				"<system-out>",
+					"unique-id: ", "test:test",
+					"display-name: successfulTest",
+				"</system-out>",
+				"<system-out>",
+					"Report Entry #1 (timestamp: ",
+					"- foo: bar",
+					"Report Entry #2 (timestamp: ",
+					"- baz: qux",
+				"</system-out>",
+				"<system-out>",
+					"normal output",
+				"</system-out>",
+				"<system-err>",
+					"error output",
+				"</system-err>")
+			.doesNotContain(STDOUT_REPORT_ENTRY_KEY, STDERR_REPORT_ENTRY_KEY);
+		//@formatter:on
+	}
+
 	@Test
 	void writesEmptySkippedElementForSkippedTestWithoutReason() throws Exception {
 		UniqueId uniqueId = engineDescriptor.getUniqueId().append("test", "test");