External mic test

Tests/LKTestHost/LKTestHost.xcodeproj/project.pbxproj

@@ -387,6 +387,7 @@
 				REGISTER_APP_GROUPS = YES;
 				SDKROOT = auto;
 				SUPPORTED_PLATFORMS = "iphoneos iphonesimulator macosx xros xrsimulator";
+				SUPPORTS_MACCATALYST = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2,7";
@@ -431,6 +432,7 @@
 				REGISTER_APP_GROUPS = YES;
 				SDKROOT = auto;
 				SUPPORTED_PLATFORMS = "iphoneos iphonesimulator macosx xros xrsimulator";
+				SUPPORTS_MACCATALYST = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2,7";

Tests/LiveKitTests/Audio/USBAudioTests.swift

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2025 LiveKit
+ *
+ * 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.
+ */
+
+#if os(iOS) || os(visionOS) || os(tvOS) || targetEnvironment(macCatalyst)
+@preconcurrency import AVFoundation
+@testable import LiveKit
+import LiveKitWebRTC
+import XCTest
+
+class USBAudioTests: LKTestCase {
+    func testInputDevice() async throws {
+        AudioManager.shared.audioSession.isAutomaticConfigurationEnabled = false
+        try AudioManager.shared.setVoiceProcessingEnabled(false)
+
+        let session = AVAudioSession.sharedInstance()
+        try session.setCategory(.playAndRecord, mode: .default)
+        try session.setActive(true)
+
+        print("Current category: \(session.category), mode: \(session.mode)")
+
+        // Print inputs
+        if let inputs = session.availableInputs {
+            print("Initial available inputs (\(inputs.count) total):")
+            for input in inputs {
+                print("Input: \(input.portName) (type: \(input.portType))")
+            }
+        }
+
+        // Find external mic
+        let externalInput = session.availableInputs?.first(where: { $0.portType == .headsetMic })
+        guard let externalInput else {
+            XCTFail("External input not found, external device required for this test")
+            return
+        }
+
+        print("External input: \(externalInput.portName)")
+
+        // Set external mic
+        try session.setPreferredInput(externalInput)
+        print("Preferred input: \(String(describing: session.preferredInput))")
+        XCTAssert(session.preferredInput != nil, "Preferred input not set")
+
+        // Connect to a Room
+        // url: "ws://192.168.1.3:7880"
+        try await withRooms([RoomTestingOptions(canPublish: true, canSubscribe: true)]) { rooms in
+            // Alias to Room
+            let room1 = rooms[0]
+
+            // Publish mic
+            try await room1.localParticipant.setMicrophone(enabled: true)
+
+            // Wait for 3 seconds...
+            try? await Task.sleep(nanoseconds: 3 * 1_000_000_000)
+
+            // Check if preferred input is still same external input
+            print("Preferred input: \(String(describing: session.preferredInput))")
+            XCTAssert(session.preferredInput?.uid == externalInput.uid, "Preferred input has changed")
+        }
+    }
+}
+#endif