From c9a396b9e3466aaea5334e2fc6136180020ab0b6 Mon Sep 17 00:00:00 2001
From: Jon Chambers <63609320+jon-signal@users.noreply.github.com>
Date: Fri, 1 Nov 2024 16:48:56 -0400
Subject: [PATCH] Deserialize null capabilities in `Device` entities as empty
 sets

---
 .../textsecuregcm/storage/Device.java         |  2 ++
 .../textsecuregcm/storage/DeviceTest.java     | 25 +++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/storage/Device.java b/service/src/main/java/org/whispersystems/textsecuregcm/storage/Device.java
index 0d4e1533c..5e674a9ae 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/storage/Device.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/storage/Device.java
@@ -6,6 +6,7 @@
 
 
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonSetter;
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import java.time.Duration;
@@ -178,6 +179,7 @@ public Set<DeviceCapability> getCapabilities() {
     return capabilities;
   }
 
+  @JsonSetter
   public void setCapabilities(@Nullable final Set<DeviceCapability> capabilities) {
     this.capabilities = (capabilities == null || capabilities.isEmpty())
         ? Collections.emptySet()
diff --git a/service/src/test/java/org/whispersystems/textsecuregcm/storage/DeviceTest.java b/service/src/test/java/org/whispersystems/textsecuregcm/storage/DeviceTest.java
index ca0aa849b..e72f80fd0 100644
--- a/service/src/test/java/org/whispersystems/textsecuregcm/storage/DeviceTest.java
+++ b/service/src/test/java/org/whispersystems/textsecuregcm/storage/DeviceTest.java
@@ -6,11 +6,15 @@
 package org.whispersystems.textsecuregcm.storage;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import java.time.Duration;
 import java.time.Instant;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
+import org.whispersystems.textsecuregcm.util.SystemMapper;
 
 class DeviceTest {
 
@@ -42,4 +46,25 @@ public void testIsExpired(final boolean primary, final Duration timeSinceLastSee
     assertEquals(expectExpired, device.isExpired());
   }
 
+  @Test
+  void deserializeCapabilities() throws JsonProcessingException {
+    {
+      final Device device = SystemMapper.jsonMapper().readValue("""
+          {
+            "capabilities": null
+          }
+          """, Device.class);
+
+      assertNotNull(device.getCapabilities(),
+          "Device deserialization should populate null capabilities with an empty set");
+    }
+
+    {
+      final Device device = SystemMapper.jsonMapper().readValue("{}", Device.class);
+
+      assertNotNull(device.getCapabilities(),
+          "Device deserialization should populate null capabilities with an empty set");
+    }
+  }
+
 }