Add getUsername default method to CredentialsProvider

libsignal-service/src/main/java/org/whispersystems/signalservice/api/util/CredentialsProvider.java

@@ -8,6 +8,7 @@ package org.whispersystems.signalservice.api.util;
 
 import org.whispersystems.signalservice.api.push.ServiceId.ACI;
 import org.whispersystems.signalservice.api.push.ServiceId.PNI;
+import org.whispersystems.signalservice.api.push.SignalServiceAddress;
 
 public interface CredentialsProvider {
   ACI getAci();
@@ -15,4 +16,14 @@ public interface CredentialsProvider {
   String getE164();
   int getDeviceId();
   String getPassword();
+
+  default String getUsername() {
+    StringBuilder sb = new StringBuilder();
+    sb.append(getAci().toString());
+    if (getDeviceId() != SignalServiceAddress.DEFAULT_DEVICE_ID) {
+      sb.append(".");
+      sb.append(getDeviceId());
+    }
+    return sb.toString();
+  }
 }

libsignal-service/src/main/java/org/whispersystems/signalservice/internal/websocket/WebSocketConnection.java

@@ -133,11 +133,7 @@ public class WebSocketConnection extends WebSocketListener {
       String filledUri;
 
       if (credentialsProvider.isPresent()) {
-        String identifier = Objects.requireNonNull(credentialsProvider.get().getAci()).toString();
+        filledUri = String.format(wsUri, credentialsProvider.get().getUsername(), credentialsProvider.get().getPassword());
-        if (credentialsProvider.get().getDeviceId() != SignalServiceAddress.DEFAULT_DEVICE_ID) {
-          identifier += "." + credentialsProvider.get().getDeviceId();
-        }
-        filledUri = String.format(wsUri, identifier, credentialsProvider.get().getPassword());
       } else {
         filledUri = wsUri;
       }

libsignal-service/src/test/java/org/whispersystems/signalservice/api/util/CredentialsProviderTest.kt

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2024 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+package org.whispersystems.signalservice.api.util
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertThrows
+import org.junit.Test
+import org.whispersystems.signalservice.api.push.ServiceId
+import org.whispersystems.signalservice.api.push.SignalServiceAddress
+import java.util.UUID
+
+class CredentialsProviderTest {
+  private fun makeProvider(aci: UUID?, deviceId: Int = SignalServiceAddress.DEFAULT_DEVICE_ID): CredentialsProvider {
+    return object : CredentialsProvider {
+      override fun getAci(): ServiceId.ACI? {
+        if (aci == null) {
+          return null
+        }
+        return ServiceId.ACI.from(aci)
+      }
+
+      override fun getPni(): ServiceId.PNI {
+        TODO("Not used")
+      }
+
+      override fun getE164(): String {
+        TODO("Not used")
+      }
+
+      override fun getDeviceId(): Int {
+        return deviceId
+      }
+
+      override fun getPassword(): String {
+        TODO("Not used")
+      }
+    }
+  }
+
+  @Test
+  fun usernameWithDefaultDeviceId() {
+    val uuid = UUID.randomUUID()
+    assertEquals(uuid.toString(), makeProvider(uuid).username)
+  }
+
+  @Test
+  fun usernameWithDeviceId() {
+    val uuid = UUID.randomUUID()
+    assertEquals("$uuid.42", makeProvider(uuid, 42).username)
+  }
+
+  @Test
+  fun usernameWithNullAci() {
+    assertThrows(NullPointerException::class.java) { makeProvider(aci = null).username }
+  }
+}