Introduce log level filtering support in LogRecordListener

Issue: #1047

Author: sbrannen

Diff for: junit-platform-commons/src/main/java/org/junit/platform/commons/logging/LogRecordListener.java

@@ -15,6 +15,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.logging.Level;
 import java.util.logging.LogRecord;
 
 import org.apiguardian.api.API;
@@ -78,4 +79,35 @@ public List<LogRecord> getLogRecords(Class<?> clazz) {
 		// @formatter:on
 	}
 
+	/**
+	 * Get the list of {@link LogRecord log records} that have been
+	 * {@linkplain #logRecordSubmitted submitted} to this listener
+	 * for the given class at the given log level.
+	 *
+	 * <p>As stated in the JavaDoc for {@code LogRecord}, a submitted
+	 * {@code LogRecord} should not be updated by the client application. Thus,
+	 * the {@code LogRecords} in the returned list should only be inspected for
+	 * testing purposes and not modified in any way.
+	 *
+	 * @param clazz the class for which to get the log records; never {@code null}
+	 * @param level the log level for which to get the log records; never {@code null}
+	 */
+	public List<LogRecord> getLogRecords(Class<?> clazz, Level level) {
+		// NOTE: we cannot use org.junit.platform.commons.util.Preconditions here
+		// since that would introduce a package cycle.
+		if (clazz == null) {
+			throw new JUnitException("Class must not be null");
+		}
+		if (level == null) {
+			throw new JUnitException("Level must not be null");
+		}
+
+		// @formatter:off
+		return this.logRecords.stream()
+				.filter(logRecord -> logRecord.getLoggerName().equals(clazz.getName()))
+				.filter(logRecord -> logRecord.getLevel() == level)
+				.collect(toList());
+		// @formatter:on
+	}
+
 }

Diff for: junit-vintage-engine/src/test/java/org/junit/vintage/engine/discovery/TestClassRequestResolverTests.java

@@ -67,8 +67,7 @@ void logsWarningOnNonFilterableRunner(LogRecordListener listener) {
 		resolve(new TestClassRequest(testClass, asList(filter)));
 
 		// @formatter:off
-		assertThat(listener.getLogRecords(TestClassRequestResolver.class).stream()
-			.filter(logRecord -> logRecord.getLevel() == Level.WARNING)
+		assertThat(listener.getLogRecords(TestClassRequestResolver.class, Level.WARNING).stream()
 			.map(LogRecord::getMessage)
 			.filter(m -> m.equals("Runner " + IgnoredClassRunner.class.getName() //
 				+ " (used on " + testClass.getName() + ") does not support filtering" //

Diff for: junit-vintage-engine/src/test/java/org/junit/vintage/engine/discovery/UniqueIdSelectorResolverTests.java

@@ -91,8 +91,7 @@ void logsWarningOnUnexpectedTestDescriptor(LogRecordListener listener) {
 
 	private void assertLoggedWarning(LogRecordListener listener, String expectedMessage) {
 		// @formatter:off
-		assertThat(listener.getLogRecords(UniqueIdSelectorResolver.class).stream()
-			.filter(logRecord -> logRecord.getLevel() == Level.WARNING)
+		assertThat(listener.getLogRecords(UniqueIdSelectorResolver.class, Level.WARNING).stream()
 			.map(LogRecord::getMessage)
 			.filter(m -> m.equals(expectedMessage))
 			.count()

Diff for: junit-vintage-engine/src/test/java/org/junit/vintage/engine/discovery/VintageDiscovererTests.java

@@ -38,7 +38,7 @@
 class VintageDiscovererTests {
 
 	@Test
-	void logsWarningWhenFilterExcludesClass(LogRecordListener listener) {
+	void logsDebugMessageWhenFilterExcludesClass(LogRecordListener listener) {
 		ClassNameFilter fooFilter = className -> includedIf(Foo.class.getName().equals(className), () -> "match",
 			() -> "no match");
 
@@ -55,8 +55,7 @@ void logsWarningWhenFilterExcludesClass(LogRecordListener listener) {
 		assertThat(testDescriptor.getChildren()).hasSize(1);
 
 		// @formatter:off
-		assertThat(listener.getLogRecords(VintageDiscoverer.class).stream()
-			.filter(logRecord -> logRecord.getLevel() == Level.FINE)
+		assertThat(listener.getLogRecords(VintageDiscoverer.class, Level.FINE).stream()
 			.map(LogRecord::getMessage)
 			.filter(m -> m.equals("Class " + Bar.class.getName() + " was excluded by a class filter: no match"))
 			.count()

Diff for: junit-vintage-engine/src/test/java/org/junit/vintage/engine/support/UniqueIdReaderTests.java

@@ -51,8 +51,7 @@ void returnsDisplayNameWhenUniqueIdCannotBeRead(LogRecordListener listener) {
 		assertEquals(description.getDisplayName(), uniqueId);
 
 		// @formatter:off
-		assertThat(listener.getLogRecords(UniqueIdReader.class).stream()
-			.filter(logRecord -> logRecord.getLevel() == Level.WARNING)
+		assertThat(listener.getLogRecords(UniqueIdReader.class, Level.WARNING).stream()
 			.map(LogRecord::getMessage)
 			.filter(m -> m.equals("Could not read unique ID for Description; using display name instead: "
 					+ description.getDisplayName()))