Add test cases for skywalking-loggings module.

skywalking-commons/skywalking-logging/skywalking-logging-api/src/main/java/com/a/eye/skywalking/api/logging/api/NoopLogger.java

@@ -7,8 +7,8 @@ package com.a.eye.skywalking.api.logging.api;
  * <p>
  * Created by xin on 2016/11/10.
  */
-public class NoopLogger implements ILog {
-    public static final ILog INSTANCE = new NoopLogger();
+public enum NoopLogger implements ILog {
+    INSTANCE;
 
     @Override
     public void info(String message) {

skywalking-commons/skywalking-logging/skywalking-logging-api/src/test/java/com/a/eye/skywalking/api/logging/api/LogManagerTest.java

+package com.a.eye.skywalking.api.logging.api;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.powermock.api.support.membermodification.MemberModifier;
+
+/**
+ * Created by wusheng on 2017/2/27.
+ */
+public class LogManagerTest {
+    @Test
+    public void testGetLogger() {
+        final TestLogger logger = new TestLogger();
+        LogManager.setLogResolver(new LogResolver() {
+            @Override
+            public ILog getLogger(Class<?> clazz) {
+                return logger;
+            }
+        });
+
+        Assert.assertEquals(logger, LogManager.getLogger(LogManagerTest.class));
+    }
+
+    @Test
+    public void testGetNoopLogger(){
+        ILog logger = LogManager.getLogger(LogManagerTest.class);
+        Assert.assertEquals(NoopLogger.INSTANCE, logger);
+    }
+
+    @Before
+    @After
+    public void clear() throws IllegalAccessException {
+        MemberModifier.field(LogManager.class, "resolver").set(null, null);
+    }
+
+
+    public class TestLogger implements ILog {
+
+        @Override public void info(String format) {
+
+        }
+
+        @Override public void info(String format, Object... arguments) {
+
+        }
+
+        @Override public void warn(String format, Object... arguments) {
+
+        }
+
+        @Override public void warn(String format, Object arguments, Throwable e) {
+
+        }
+
+        @Override public void error(String format, Throwable e) {
+
+        }
+
+        @Override public void error(String format, Object arguments, Throwable e) {
+
+        }
+
+        @Override public boolean isDebugEnable() {
+            return false;
+        }
+
+        @Override public boolean isInfoEnable() {
+            return false;
+        }
+
+        @Override public boolean isWarnEnable() {
+            return false;
+        }
+
+        @Override public boolean isErrorEnable() {
+            return false;
+        }
+
+        @Override public void debug(String format) {
+
+        }
+
+        @Override public void debug(String format, Object... arguments) {
+
+        }
+
+        @Override public void error(String format) {
+
+        }
+    }
+}

skywalking-commons/skywalking-logging/skywalking-logging-api/src/test/java/com/a/eye/skywalking/api/logging/api/NoopLoggerTest.java

+package com.a.eye.skywalking.api.logging.api;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import static com.a.eye.skywalking.api.logging.api.NoopLogger.INSTANCE;
+
+/**
+ * Created by wusheng on 2017/2/27.
+ */
+public class NoopLoggerTest {
+    @Test
+    public void testOnNothing(){
+        Assert.assertFalse(INSTANCE.isDebugEnable());
+        Assert.assertFalse(INSTANCE.isInfoEnable());
+        Assert.assertFalse(INSTANCE.isErrorEnable());
+        Assert.assertFalse(INSTANCE.isWarnEnable());
+
+        INSTANCE.debug("Any string");
+        INSTANCE.debug("Any string", new Object[0]);
+        INSTANCE.info("Any string");
+        INSTANCE.info("Any string", new Object[0]);
+        INSTANCE.warn("Any string", new Object[0]);
+        INSTANCE.warn("Any string", new Object[0], new NullPointerException());
+        INSTANCE.error("Any string");
+        INSTANCE.error("Any string", new NullPointerException());
+        INSTANCE.error("Any string", new Object[0], new NullPointerException());
+    }
+}