🚩RUM-1755 Add config overrides for debug launch arguments

Adds two launch arguments:
DD_DEBUG sets sampling to 100%, verbosity to debug, and upload frequency to freqeunt
DD_DEBUG_RUM enables Datadog.debugRUM

All of these settings are changed during initialization to override whatever configuration the user set

Datadog/Datadog.xcodeproj/xcshareddata/xcschemes/Example.xcscheme

@@ -50,6 +50,16 @@
             ReferencedContainer = "container:Datadog.xcodeproj">
          </BuildableReference>
       </BuildableProductRunnable>
+      <CommandLineArguments>
+         <CommandLineArgument
+            argument = "DD_DEBUG"
+            isEnabled = "NO">
+         </CommandLineArgument>
+         <CommandLineArgument
+            argument = "DD_DEBUG_RUM"
+            isEnabled = "NO">
+         </CommandLineArgument>
+      </CommandLineArguments>
       <EnvironmentVariables>
          <EnvironmentVariable
             key = "DD_TEST_SCENARIO_CLASS_NAME"

Sources/Datadog/Core/System/MobileDevice.swift

@@ -13,6 +13,7 @@ internal class MobileDevice {
     let model: String
     let osName: String
     let osVersion: String
+    let processInfo: ProcessInfo
 
     // MARK: - Battery status monitoring
 
@@ -40,13 +41,15 @@ internal class MobileDevice {
         model: String,
         osName: String,
         osVersion: String,
+        processInfo: ProcessInfo,
         enableBatteryStatusMonitoring: @escaping () -> Void,
         resetBatteryStatusMonitoring: @escaping () -> Void,
         currentBatteryStatus: @escaping () -> BatteryStatus
     ) {
         self.model = model
         self.osName = osName
         self.osVersion = osVersion
+        self.processInfo = processInfo
         self.enableBatteryStatusMonitoring = enableBatteryStatusMonitoring
         self.resetBatteryStatusMonitoring = resetBatteryStatusMonitoring
         self.currentBatteryStatus = currentBatteryStatus
@@ -63,6 +66,7 @@ internal class MobileDevice {
             model: uiDevice.model,
             osName: uiDevice.systemName,
             osVersion: uiDevice.systemVersion,
+            processInfo: processInfo,
             enableBatteryStatusMonitoring: { uiDevice.isBatteryMonitoringEnabled = true },
             resetBatteryStatusMonitoring: { uiDevice.isBatteryMonitoringEnabled = wasBatteryMonitoringEnabled },
             currentBatteryStatus: {
@@ -74,28 +78,51 @@ internal class MobileDevice {
             }
         )
     }
+
+    // MARK: - Singleton
+    private static var _instance: MobileDevice?
+
     /// Returns current mobile device  if `UIDevice` is available on this platform.
     /// On other platforms returns `nil`.
     static var current: MobileDevice {
-        #if !targetEnvironment(simulator)
-        // Real device
-        return MobileDevice(
-            uiDevice: UIDevice.current,
-            processInfo: ProcessInfo.processInfo,
-            notificationCenter: .default
-        )
-        #else
-        // iOS Simulator - battery monitoring doesn't work on Simulator, so return "always OK" value
-        return MobileDevice(
-            model: UIDevice.current.model,
-            osName: UIDevice.current.systemName,
-            osVersion: UIDevice.current.systemVersion,
-            enableBatteryStatusMonitoring: {},
-            resetBatteryStatusMonitoring: {},
-            currentBatteryStatus: { BatteryStatus(state: .full, level: 1, isLowPowerModeEnabled: false) }
-        )
-        #endif
+        get {
+            if let instance = _instance {
+                return instance
+            }
+
+            #if !targetEnvironment(simulator)
+            // Real device
+            _instance = MobileDevice(
+                uiDevice: UIDevice.current,
+                processInfo: ProcessInfo.processInfo,
+                notificationCenter: .default
+            )
+            #else
+            // iOS Simulator - battery monitoring doesn't work on Simulator, so return "always OK" value
+            _instance = MobileDevice(
+                model: UIDevice.current.model,
+                osName: UIDevice.current.systemName,
+                osVersion: UIDevice.current.systemVersion,
+                processInfo: ProcessInfo.processInfo,
+                enableBatteryStatusMonitoring: {},
+                resetBatteryStatusMonitoring: {},
+                currentBatteryStatus: { BatteryStatus(state: .full, level: 1, isLowPowerModeEnabled: false) }
+            )
+            #endif
+
+            // swiftlint:disable:next force_unwrapping
+            return _instance!
+        }
+        set(newInstance) {
+            _instance = newInstance
+        }
+    }
+
+    #if DD_SDK_COMPILED_FOR_TESTING
+    static func clearForTesting() {
+        _instance = nil
     }
+    #endif
 
     private static func toBatteryState(_ uiDeviceBatteryState: UIDevice.BatteryState) -> BatteryStatus.State {
         switch uiDeviceBatteryState {

Sources/Datadog/Datadog.swift

@@ -70,18 +70,40 @@ public class Datadog {
         trackingConsent: TrackingConsent,
         configuration: Configuration
     ) {
+        var mutableConfiguration = configuration
+
         // TODO: RUMM-511 remove this warning
         #if targetEnvironment(macCatalyst)
         consolePrint("⚠️ Catalyst is not officially supported by Datadog SDK: some features may NOT be functional!")
         #endif
+
+        let mobileDevice = MobileDevice.current
+        let debugOverride = mobileDevice.processInfo.arguments.contains(LaunchArguments.Debug)
+        if debugOverride {
+            consolePrint("⚠️ Overriding sampling, verbosity, and upload frequency due to \(LaunchArguments.Debug) launch argument")
+            let rebuilder = Configuration.Builder(configuration: mutableConfiguration)
+                .set(rumSessionsSamplingRate: 100)
+                .set(batchSize: .small)
+                .set(uploadFrequency: .frequent)
+            mutableConfiguration = rebuilder.build()
+            Datadog.verbosityLevel = .debug
+        }
+
         do {
             try initializeOrThrow(
                 initialTrackingConsent: trackingConsent,
                 configuration: try FeaturesConfiguration(
-                    configuration: configuration,
+                    configuration: mutableConfiguration,
                     appContext: appContext
                 )
             )
+
+            // Now that RUM is potentially initialized, override the debugRUM value
+            let debugRumOverride = mobileDevice.processInfo.arguments.contains(LaunchArguments.DebugRUM)
+            if debugRumOverride {
+                consolePrint("⚠️ Overriding RUM debugging due to \(LaunchArguments.DebugRUM) launch argument")
+                Datadog.debugRUM = true
+            }
         } catch {
             consolePrint("\(error)")
         }
@@ -140,6 +162,10 @@ public class Datadog {
     }
 
     // MARK: - Internal
+    internal struct LaunchArguments {
+        static let Debug = "DD_DEBUG"
+        static let DebugRUM = "DD_DEBUG_RUM"
+    }
 
     internal static var instance: Datadog?
 

Sources/Datadog/DatadogConfiguration.swift

@@ -345,6 +345,11 @@ extension Datadog {
                 )
             }
 
+            /// Used internally to rebuild a configuration based on launch arguments
+            internal init(configuration: Configuration) {
+                self.configuration = configuration
+            }
+
             /// Sets the Datadog server endpoint where data is sent.
             ///
             /// If set, it will override values set by any of these deprecated APIs:

Tests/DatadogTests/Datadog/DatadogTests.swift

@@ -18,6 +18,8 @@ class DatadogTests: XCTestCase {
 
     override func setUp() {
         super.setUp()
+        MobileDevice.clearForTesting()
+
         XCTAssertFalse(Datadog.isInitialized)
         printFunction = PrintFunctionMock()
         consolePrint = printFunction.print
@@ -329,6 +331,67 @@ class DatadogTests: XCTestCase {
         }
     }
 
+    func testSupplyingDebugLaunchArgument_itOverridesUserSettings() {
+        let mockProcessInfo = ProcessInfoMock(
+            arguments: [Datadog.LaunchArguments.Debug]
+        )
+
+        MobileDevice.current = MobileDevice.mockWith(
+            processInfo: mockProcessInfo
+        )
+
+        let configuration = rumBuilder
+            .set(uploadFrequency: .rare)
+            .set(rumSessionsSamplingRate: 20.0)
+            .set(batchSize: .medium)
+            .build()
+
+        Datadog.initialize(
+            appContext: .mockAny(),
+            trackingConsent: .pending,
+            configuration: configuration
+        )
+
+        let expectedPerformancePreset = PerformancePreset(
+            batchSize: .small,
+            uploadFrequency: .frequent,
+            bundleType: .iOSApp
+        )
+        XCTAssertEqual(RUMFeature.instance?.configuration.sessionSamplingRate, 100)
+        XCTAssertEqual(TracingFeature.instance?.configuration.common.performance, expectedPerformancePreset)
+        XCTAssertEqual(LoggingFeature.instance?.configuration.common.performance, expectedPerformancePreset)
+        XCTAssertEqual(Datadog.verbosityLevel, .debug)
+
+        // Clear default verbosity after this test
+        Datadog.verbosityLevel = nil
+        Datadog.flushAndDeinitialize()
+    }
+
+    func testSupplyingRumDebugLaunchArgument_itSetsRumDebug() {
+        let mockProcessInfo = ProcessInfoMock(
+            arguments: [Datadog.LaunchArguments.DebugRUM]
+        )
+
+        MobileDevice.current = MobileDevice.mockWith(
+            processInfo: mockProcessInfo
+        )
+
+        let configuration = rumBuilder
+            .build()
+
+        Datadog.initialize(
+            appContext: .mockAny(),
+            trackingConsent: .pending,
+            configuration: configuration
+        )
+
+        XCTAssertTrue(Datadog.debugRUM)
+
+        // Clear debug after test
+        Datadog.debugRUM = false
+        Datadog.flushAndDeinitialize()
+    }
+
     // MARK: - Public APIs
 
     func testTrackingConsent() {

Tests/DatadogTests/Datadog/Mocks/CoreMocks.swift

@@ -786,6 +786,7 @@ extension MobileDevice {
         model: String = .mockAny(),
         osName: String = .mockAny(),
         osVersion: String = .mockAny(),
+        processInfo: ProcessInfo = ProcessInfoMock(),
         enableBatteryStatusMonitoring: @escaping () -> Void = {},
         resetBatteryStatusMonitoring: @escaping () -> Void = {},
         currentBatteryStatus: @escaping () -> BatteryStatus = { .mockAny() }
@@ -794,6 +795,7 @@ extension MobileDevice {
             model: model,
             osName: osName,
             osVersion: osVersion,
+            processInfo: processInfo,
             enableBatteryStatusMonitoring: enableBatteryStatusMonitoring,
             resetBatteryStatusMonitoring: resetBatteryStatusMonitoring,
             currentBatteryStatus: currentBatteryStatus

Tests/DatadogTests/Datadog/Mocks/SystemFrameworks/FoundationMocks.swift

@@ -408,12 +408,16 @@ extension URLRequest: AnyMockable {
 
 class ProcessInfoMock: ProcessInfo {
     private var _isLowPowerModeEnabled: Bool
+    private var _arguments: [String]
 
-    init(isLowPowerModeEnabled: Bool = .mockAny()) {
+    init(isLowPowerModeEnabled: Bool = .mockAny(), arguments: [String] = []) {
         _isLowPowerModeEnabled = isLowPowerModeEnabled
+        _arguments = arguments
     }
 
     override var isLowPowerModeEnabled: Bool { _isLowPowerModeEnabled }
+
+    override var arguments: [String] { _arguments }
 }
 
 // MARK: - URLSession