[apple] [infra] Refactor unification of app and main logs for iOS devices and MacCatalyst

src/Microsoft.DotNet.XHarness.Apple/AppOperations/AppRunnerBase.cs

@@ -327,11 +327,8 @@ private CancellationTokenSource CaptureLogStream(string appName, bool useSimctl,
         }
         else
         {
-            // For MacCatalyst, the test output log does not propagate to the main log.
-            // Hence, we duplicate the log to the main console log to simplify the UX of failure investigation.
-            IFileBackedLog aggregatedAppOutputLog = Log.CreateReadableAggregatedLog(_mainLog, log);
             _processManager
-                .ExecuteCommandAsync("log", logArgs, _mainLog, aggregatedAppOutputLog, aggregatedAppOutputLog, TimeSpan.FromDays(1), cancellationToken: streamCancellation)
+                .ExecuteCommandAsync("log", logArgs, _mainLog, log, log, TimeSpan.FromDays(1), cancellationToken: streamCancellation)
                 .DoNotAwait();
         }
 

src/Microsoft.DotNet.XHarness.Apple/AppOperations/AppTester.cs

@@ -362,15 +362,12 @@ private async Task RunDeviceTests(
             // We need to check for MT1111 (which means that mlaunch won't wait for the app to exit)
             IFileBackedLog aggregatedLog = Log.CreateReadableAggregatedLog(_mainLog, testReporter.CallbackLog);
 
-            // The app output log is not directly accessible. 
-            // Hence, we duplicate the log to the main console log to simplify the UX of failure investigation.
-            IFileBackedLog aggregatedAppOutputLog = Log.CreateReadableAggregatedLog(_mainLog, appOutputLog);
 
             var result = await RunAndWatchForAppSignal(() => _processManager.ExecuteCommandAsync(
                 mlaunchArguments,
                 aggregatedLog,
-                aggregatedAppOutputLog,
-                aggregatedAppOutputLog,
+                appOutputLog,
+                appOutputLog,
                 timeout,
                 envVars,
                 cancellationToken: cancellationToken));

src/Microsoft.DotNet.XHarness.Apple/Orchestration/TestOrchestrator.cs

@@ -248,6 +248,12 @@ private async Task<ExitCode> ExecuteApp(
             skippedTestClasses: classMethodFilters?.ToArray(),
             cancellationToken: cancellationToken);
 
+        if (!target.Platform.IsSimulator()) // Simulator app logs are already included in the main log
+        {
+            // Copy system and application logs to the main log for better failure investigation.
+            CopyLogsToMainLog();
+        }
+
         return ParseResult(testResult, resultMessage, appTester.ListenerConnected);
     }
 
@@ -278,6 +284,9 @@ private async Task<ExitCode> ExecuteMacCatalystApp(
             skippedTestClasses: classMethodFilters?.ToArray(),
             cancellationToken: cancellationToken);
 
+        // Copy system and application logs to the main log for better failure investigation.
+        CopyLogsToMainLog();
+
         return ParseResult(testResult, resultMessage, appTester.ListenerConnected);
     }
 
@@ -364,4 +373,42 @@ ExitCode LogProblem(string message, ExitCode defaultExitCode)
                 return ExitCode.GENERAL_FAILURE;
         }
     }
+
+    /// <summary>
+    /// Copy system and application logs to the main log for better failure investigation.
+    /// </summary>
+    private void CopyLogsToMainLog()
+    {
+        var logs = _logs.Where(log => log.Description == LogType.SystemLog.ToString() || log.Description == LogType.ApplicationLog.ToString()).ToList();
+
+        foreach (var log in logs)
+        {
+            _mainLog.WriteLine($"==================== {log.Description} ====================");
+            _mainLog.WriteLine($"Log file: {log.FullPath}");
+
+            try
+            {
+                // Read and append log content to the main log
+                string logContent;
+                using (var reader = log.GetReader())
+                {
+                    while (!reader.EndOfStream)
+                    {
+                        logContent = reader.ReadLine()!;
+                        if (logContent != null)
+                        {
+                            _mainLog.WriteLine(logContent);
+                        }
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                _mainLog.WriteLine($"Failed to read {log.Description}: {ex.Message}");
+            }
+
+            _mainLog.WriteLine($"==================== End of {log.Description} ====================");
+            _mainLog.WriteLine(string.Empty);
+        }
+    }
 }