Add unit tests for alarm-plugin module

oap-server/exporter/src/test/java/org/apache/skywalking/oap/server/exporter/provider/grpc/GRPCExporterTest.java

@@ -95,7 +95,7 @@ public void onExit() {
     private List<GRPCExporter.ExportData> dataList() {
         List<GRPCExporter.ExportData> dataList = new LinkedList<>();
         dataList.add(exporter.new ExportData(metaInfo, new MockIndicator()));
-        dataList.add(exporter.new ExportData(metaInfo, new MockIntValueIndicatior()));
+        dataList.add(exporter.new ExportData(metaInfo, new MockIntValueIndicator()));
         dataList.add(exporter.new ExportData(metaInfo, new MockLongValueIndicator()));
         dataList.add(exporter.new ExportData(metaInfo, new MockDoubleValueIndicator()));
         return dataList;

oap-server/exporter/src/test/java/org/apache/skywalking/oap/server/exporter/provider/grpc/MockIntValueIndicatior.java → oap-server/exporter/src/test/java/org/apache/skywalking/oap/server/exporter/provider/grpc/MockIntValueIndicator.java

@@ -23,7 +23,7 @@
 /**
  * Created by dengming, 2019.04.20
  */
-public class MockIntValueIndicatior extends MockIndicator implements IntValueHolder {
+public class MockIntValueIndicator extends MockIndicator implements IntValueHolder {
     @Override
     public int getValue() {
         return 12;

oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/AlarmCore.java

@@ -18,19 +18,20 @@
 
 package org.apache.skywalking.oap.server.core.alarm.provider;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeUnit;
 import org.apache.skywalking.oap.server.core.alarm.AlarmCallback;
 import org.apache.skywalking.oap.server.core.alarm.AlarmMessage;
 import org.joda.time.LocalDateTime;
 import org.joda.time.Minutes;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
 /**
  * Alarm core includes metric values in certain time windows based on alarm settings. By using its internal timer
  * trigger and the alarm rules to decides whether send the alarm to database and webhook(s)
@@ -50,11 +51,8 @@ public class AlarmCore {
 
             String indicatorName = rule.getIndicatorName();
 
-            List<RunningRule> runningRules = runningContext.get(indicatorName);
-            if (runningRules == null) {
-                runningRules = new ArrayList<>();
-                runningContext.put(indicatorName, runningRules);
-            }
+            List<RunningRule> runningRules = runningContext.computeIfAbsent(indicatorName, key -> new ArrayList<>());
+
             runningRules.add(runningRule);
         });
     }
@@ -71,7 +69,7 @@ public void start(List<AlarmCallback> allCallbacks) {
                 List<AlarmMessage> alarmMessageList = new ArrayList<>(30);
                 LocalDateTime checkTime = LocalDateTime.now();
                 int minutes = Minutes.minutesBetween(lastExecuteTime, checkTime).getMinutes();
-                boolean[] hasExecute = new boolean[] {false};
+                boolean[] hasExecute = new boolean[]{false};
                 runningContext.values().forEach(ruleList -> ruleList.forEach(runningRule -> {
                     if (minutes > 0) {
                         runningRule.moveTo(checkTime);

oap-server/server-alarm-plugin/src/test/java/org/apache/skywalking/oap/server/core/alarm/provider/AlarmModuleProviderTest.java

@@ -0,0 +1,86 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+package org.apache.skywalking.oap.server.core.alarm.provider;
+
+import org.apache.skywalking.oap.server.core.CoreModule;
+import org.apache.skywalking.oap.server.core.alarm.AlarmModule;
+import org.apache.skywalking.oap.server.library.module.ModuleProvider;
+import org.junit.Before;
+import org.junit.Test;
+import org.powermock.reflect.Whitebox;
+
+import java.util.Iterator;
+import java.util.ServiceLoader;
+
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Created by dengming, 2019.04.22
+ */
+public class AlarmModuleProviderTest {
+
+    private AlarmModuleProvider moduleProvider;
+
+    @Before
+    public void setUp() throws Exception {
+        ServiceLoader<ModuleProvider> serviceLoader = ServiceLoader.load(ModuleProvider.class);
+        Iterator<ModuleProvider> providerIterator = serviceLoader.iterator();
+
+        assertTrue(providerIterator.hasNext());
+
+        moduleProvider = (AlarmModuleProvider) providerIterator.next();
+
+        moduleProvider.createConfigBeanIfAbsent();
+
+        moduleProvider.prepare();
+    }
+
+    @Test
+    public void name() {
+        assertEquals("default", moduleProvider.name());
+    }
+
+    @Test
+    public void module() {
+        assertEquals(AlarmModule.class, moduleProvider.module());
+    }
+
+    @Test
+    public void start() throws Exception {
+        moduleProvider.start();
+    }
+
+    @Test
+    public void notifyAfterCompleted() throws Exception {
+
+        NotifyHandler handler = mock(NotifyHandler.class);
+
+        doNothing().when(handler).initCache(null);
+
+        Whitebox.setInternalState(moduleProvider, "notifyHandler", handler);
+        moduleProvider.notifyAfterCompleted();
+    }
+
+    @Test
+    public void requiredModules() {
+        String[] modules = moduleProvider.requiredModules();
+        assertArrayEquals(new String[]{CoreModule.NAME}, modules);
+    }
+}