Represent device names as byte arrays

service/src/test/java/org/whispersystems/textsecuregcm/util/DeviceNameByteArrayAdapterTest.java

@@ -0,0 +1,51 @@
+package org.whispersystems.textsecuregcm.util;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.io.IOException;
+import java.util.Base64;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+class DeviceNameByteArrayAdapterTest {
+
+  @Test
+  void serialize() throws IOException {
+    final byte[] deviceName = TestRandomUtil.nextBytes(16);
+    final JsonGenerator jsonGenerator = mock(JsonGenerator.class);
+
+    new DeviceNameByteArrayAdapter.Serializer().serialize(deviceName, jsonGenerator, mock(SerializerProvider.class));
+
+    verify(jsonGenerator).writeString(Base64.getEncoder().encodeToString(deviceName));
+  }
+
+  @ParameterizedTest
+  @MethodSource
+  void deserialize(final String encodedString, final byte[] expectedBytes) throws IOException {
+    final JsonParser jsonParser = mock(JsonParser.class);
+    when(jsonParser.getValueAsString()).thenReturn(encodedString);
+
+    assertArrayEquals(expectedBytes,
+        new DeviceNameByteArrayAdapter.Deserializer().deserialize(jsonParser, mock(DeserializationContext.class)));
+  }
+
+  private static List<Arguments> deserialize() {
+    final byte[] deviceName = TestRandomUtil.nextBytes(16);
+
+    return List.of(
+        Arguments.of(Base64.getEncoder().encodeToString(deviceName), deviceName),
+        Arguments.of("This is not a valid Base64 string", null)
+    );
+  }
+}