feature: Add OFF log level to StandardEnvironment (#3904)

Author: gchaperon

src/main/java/spoon/support/Level.java

@@ -11,7 +11,7 @@
  * Enum for representing logging levels.
  */
 public enum Level {
-	ERROR(100), WARN(200), INFO(300), DEBUG(400), TRACE(500);
+	OFF(0), ERROR(100), WARN(200), INFO(300), DEBUG(400), TRACE(500);
 
 	private final int levelValue;
 

src/main/java/spoon/support/StandardEnvironment.java

@@ -274,7 +274,7 @@ public void report(Processor<?> processor, Level level, String message) {
 	}
 
 	private void print(String message, Level messageLevel) {
-		if (messageLevel.toInt() <= this.level.toInt()) {
+		if (this.level != Level.OFF && messageLevel.toInt() <= this.level.toInt()) {
 			switch (messageLevel) {
 				case ERROR: logger.error(message);
 					break;

src/test/java/spoon/test/logging/LogTest.java

@@ -22,6 +22,7 @@
 import org.junit.runners.Parameterized;
 import spoon.Launcher;
 import spoon.MavenLauncher;
+import spoon.support.JavaOutputProcessor;
 import spoon.support.Level;
 import uk.org.lidalia.slf4jtest.TestLogger;
 import uk.org.lidalia.slf4jtest.TestLoggerFactory;
@@ -43,7 +44,8 @@ public static Collection<Object[]> data() {
 					{Level.DEBUG, 6 },
 					{Level.INFO, 2 },
 					{Level.WARN, 0 },
-					{Level.ERROR, 0 }
+					{Level.ERROR, 0 },
+					{Level.OFF, 0}
 			});
 		}
 
@@ -87,5 +89,26 @@ public void testMavenLauncherLogs() {
 			mavenLauncher = new MavenLauncher("./pom.xml", MavenLauncher.SOURCE_TYPE.APP_SOURCE, new String[]{"./"});
 			assertEquals("Running in FULLCLASSPATH mode. Classpath is manually set (doc: http://spoon.gforge.inria.fr/launcher.html).",logger.getLoggingEvents().get(0).getMessage());
 		}
+
+		@Test
+		public void testLoggingOff() {
+			// contract: When logging is off, no message should me logged independent of logging level.
+			final TestLogger logger = TestLoggerFactory.getTestLogger(Launcher.class);
+			final Launcher launcher = new Launcher();
+			logger.clear();
+			launcher.setArgs(new String[] {
+					"-i", "./src/test/java/spoon/test/logging",
+					"--level", Level.OFF.toString()
+			});
+
+			// test messages with all logging levels
+			for (Level level : Level.values()) {
+				launcher.getEnvironment().report(new JavaOutputProcessor(), level,
+						"This is a message with level " + level.toString());
+			}
+			assertEquals(0, logger.getLoggingEvents().size());
+		}
 	}
+
+
 }