Enforce 60 seconds minimum datafile refresh time (#72)

Author: Vignesh Raja

android-sdk/src/main/java/com/optimizely/ab/android/sdk/OptimizelyManager.java

@@ -89,6 +89,16 @@ public class OptimizelyManager {
         this.logger = logger;
     }
 
+    @NonNull
+    public Long getDataFileDownloadInterval() {
+        return dataFileDownloadInterval;
+    }
+
+    @NonNull
+    public TimeUnit getDataFileDownloadIntervalTimeUnit() {
+        return dataFileDownloadIntervalTimeUnit;
+    }
+
     /**
      * Returns the {@link OptimizelyManager} builder
      *
@@ -606,6 +616,14 @@ public Builder withDataFileDownloadInterval(long interval, @NonNull TimeUnit tim
         public OptimizelyManager build() {
             final Logger logger = LoggerFactory.getLogger(OptimizelyManager.class);
 
+            // AlarmManager doesn't allow intervals less than 60 seconds
+            if (dataFileDownloadIntervalTimeUnit.toMillis(dataFileDownloadInterval) < (60 * 1000)) {
+                dataFileDownloadIntervalTimeUnit = TimeUnit.SECONDS;
+                dataFileDownloadInterval = 60L;
+                logger.warn("Minimum datafile polling interval is 60 seconds. " +
+                        "Defaulting to 60 seconds.");
+            }
+
             return new OptimizelyManager(projectId,
                     eventHandlerDispatchInterval,
                     eventHandlerDispatchIntervalTimeUnit,

android-sdk/src/test/java/com/optimizely/ab/android/sdk/OptimizelyManagerBuilderTest.java

@@ -0,0 +1,57 @@
+/****************************************************************************
+ * Copyright 2017, Optimizely, Inc. and contributors                        *
+ *                                                                          *
+ * Licensed 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 com.optimizely.ab.android.sdk;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import java.util.concurrent.TimeUnit;
+
+import static junit.framework.Assert.assertEquals;
+
+@RunWith(MockitoJUnitRunner.class)
+public class OptimizelyManagerBuilderTest {
+
+    /**
+     * Verify that building the {@link OptimizelyManager} with a polling interval less than 60
+     * seconds defaults to 60 seconds.
+     */
+    @Test
+    public void testBuildWithInvalidPollingInterval() {
+        OptimizelyManager manager = OptimizelyManager.builder("1")
+                .withDataFileDownloadInterval(5, TimeUnit.SECONDS)
+                .build();
+
+        assertEquals(60L, manager.getDataFileDownloadInterval().longValue());
+        assertEquals(TimeUnit.SECONDS, manager.getDataFileDownloadIntervalTimeUnit());
+    }
+
+    /**
+     * Verify that building the {@link OptimizelyManager} with a polling interval greater than 60
+     * seconds is properly registered.
+     */
+    @Test
+    public void testBuildWithValidPollingInterval() {
+        OptimizelyManager manager = OptimizelyManager.builder("1")
+                .withDataFileDownloadInterval(61, TimeUnit.SECONDS)
+                .build();
+
+        assertEquals(61L, manager.getDataFileDownloadInterval().longValue());
+        assertEquals(TimeUnit.SECONDS, manager.getDataFileDownloadIntervalTimeUnit());
+    }
+}