Add a dynamic configuration manager

service/src/test/java/org/whispersystems/textsecuregcm/storage/DynamicConfigurationManagerTest.java

@@ -0,0 +1,43 @@
+package org.whispersystems.textsecuregcm.storage;
+
+import com.amazonaws.services.appconfig.AmazonAppConfig;
+import com.amazonaws.services.appconfig.model.GetConfigurationRequest;
+import com.amazonaws.services.appconfig.model.GetConfigurationResult;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.ArgumentCaptor;
+
+import java.nio.ByteBuffer;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class DynamicConfigurationManagerTest {
+
+  private DynamicConfigurationManager dynamicConfigurationManager;
+  private AmazonAppConfig             appConfig;
+
+  @Before
+  public void setup() {
+    this.appConfig                   = mock(AmazonAppConfig.class);
+    this.dynamicConfigurationManager = new DynamicConfigurationManager(appConfig, "foo", "bar", "baz", "poof");
+  }
+
+  @Test
+  public void testGetConfig() {
+    ArgumentCaptor<GetConfigurationRequest> captor = ArgumentCaptor.forClass(GetConfigurationRequest.class);
+    when(appConfig.getConfiguration(captor.capture())).thenReturn(new GetConfigurationResult().withContent(ByteBuffer.wrap("test: true".getBytes()))
+                                                                                              .withConfigurationVersion("1"));
+
+    dynamicConfigurationManager.start();
+
+    assertThat(captor.getValue().getApplication()).isEqualTo("foo");
+    assertThat(captor.getValue().getEnvironment()).isEqualTo("bar");
+    assertThat(captor.getValue().getConfiguration()).isEqualTo("baz");
+    assertThat(captor.getValue().getClientId()).isEqualTo("poof");
+
+    assertThat(dynamicConfigurationManager.getConfiguration()).isNotNull();
+  }
+}