Better diagnostics for test runner

src/Tools/Source/RunTests/TestRunner.cs

@@ -123,78 +123,85 @@ private void Print(List<TestResult> testResults)
 
         private async Task<TestResult> RunTest(string assemblyPath, CancellationToken cancellationToken)
         {
-            var assemblyName = Path.GetFileName(assemblyPath);
-            var extension = _useHtml ? ".TestResults.html" : ".TestResults.xml";
-            var resultsPath = Path.Combine(Path.GetDirectoryName(assemblyPath), Path.ChangeExtension(assemblyName, extension));
-            DeleteFile(resultsPath);
-
-            var builder = new StringBuilder();
-            builder.AppendFormat(@"""{0}""", assemblyPath);
-            builder.AppendFormat(@" -{0} ""{1}""", _useHtml ? "html" : "xml", resultsPath);
-            builder.Append(" -noshadow");
-
-            var errorOutput = new StringBuilder();
-            var start = DateTime.UtcNow;
-
-            var xunitPath = UpgradedTests.Contains(assemblyName) ? Path.Combine($"{Path.GetDirectoryName(_xunitConsolePath)}", @"..\..\..\xunit.runner.console\2.1.0-beta4-build3109\tools", $"{Path.GetFileName(_xunitConsolePath)}") : _xunitConsolePath;
-            var processOutput = await ProcessRunner.RunProcessAsync(
-                xunitPath,
-                builder.ToString(),
-                lowPriority: false,
-                displayWindow: false,
-                captureOutput: true,
-                cancellationToken: cancellationToken).ConfigureAwait(false);
-            var span = DateTime.UtcNow - start;
-
-            if (processOutput.ExitCode != 0)
-            {
-                // On occasion we get a non-0 output but no actual data in the result file.  The could happen
-                // if xunit manages to crash when running a unit test (a stack overflow could cause this, for instance).
-                // To avoid losing information, write the process output to the console.  In addition, delete the results
-                // file to avoid issues with any tool attempting to interpret the (potentially malformed) text.
-                var all = string.Empty;
-                try
-                {
-                    all = File.ReadAllText(resultsPath).Trim();
-                }
-                catch
+            try
+            { 
+                var assemblyName = Path.GetFileName(assemblyPath);
+                var extension = _useHtml ? ".TestResults.html" : ".TestResults.xml";
+                var resultsPath = Path.Combine(Path.GetDirectoryName(assemblyPath), Path.ChangeExtension(assemblyName, extension));
+                DeleteFile(resultsPath);
+
+                var builder = new StringBuilder();
+                builder.AppendFormat(@"""{0}""", assemblyPath);
+                builder.AppendFormat(@" -{0} ""{1}""", _useHtml ? "html" : "xml", resultsPath);
+                builder.Append(" -noshadow");
+
+                var errorOutput = new StringBuilder();
+                var start = DateTime.UtcNow;
+
+                var xunitPath = UpgradedTests.Contains(assemblyName) ? Path.Combine($"{Path.GetDirectoryName(_xunitConsolePath)}", @"..\..\..\xunit.runner.console\2.1.0-beta4-build3109\tools", $"{Path.GetFileName(_xunitConsolePath)}") : _xunitConsolePath;
+                var processOutput = await ProcessRunner.RunProcessAsync(
+                    xunitPath,
+                    builder.ToString(),
+                    lowPriority: false,
+                    displayWindow: false,
+                    captureOutput: true,
+                    cancellationToken: cancellationToken).ConfigureAwait(false);
+                var span = DateTime.UtcNow - start;
+
+                if (processOutput.ExitCode != 0)
                 {
-                    // Happens if xunit didn't produce a log file
-                }
+                    // On occasion we get a non-0 output but no actual data in the result file.  The could happen
+                    // if xunit manages to crash when running a unit test (a stack overflow could cause this, for instance).
+                    // To avoid losing information, write the process output to the console.  In addition, delete the results
+                    // file to avoid issues with any tool attempting to interpret the (potentially malformed) text.
+                    var all = string.Empty;
+                    try
+                    {
+                        all = File.ReadAllText(resultsPath).Trim();
+                    }
+                    catch
+                    {
+                        // Happens if xunit didn't produce a log file
+                    }
 
-                bool noResultsData = (all.Length == 0);
-                if (noResultsData)
-                {
-                    var output = processOutput.OutputLines.Concat(processOutput.ErrorLines);
-                    Console.Write(string.Join(Environment.NewLine, output));
+                    bool noResultsData = (all.Length == 0);
+                    if (noResultsData)
+                    {
+                        var output = processOutput.OutputLines.Concat(processOutput.ErrorLines);
+                        Console.Write(string.Join(Environment.NewLine, output));
 
-                    // Delete the output file.
-                    File.Delete(resultsPath);
-                }
+                        // Delete the output file.
+                        File.Delete(resultsPath);
+                    }
 
-                errorOutput.AppendLine($"Command: {_xunitConsolePath} {builder}");
+                    errorOutput.AppendLine($"Command: {_xunitConsolePath} {builder}");
 
-                if (processOutput.ErrorLines.Any())
-                {
-                    foreach (var line in processOutput.ErrorLines)
+                    if (processOutput.ErrorLines.Any())
                     {
-                        errorOutput.AppendLine(line);
+                        foreach (var line in processOutput.ErrorLines)
+                        {
+                            errorOutput.AppendLine(line);
+                        }
+                    }
+                    else
+                    {
+                        errorOutput.AppendLine($"xunit produced no error output but had exit code {processOutput.ExitCode}");
                     }
-                }
-                else
-                {
-                    errorOutput.AppendLine($"xunit produced no error output but had exit code {processOutput.ExitCode}");
-                }
 
-                // If the results are html, use Process.Start to open in the browser.
+                    // If the results are html, use Process.Start to open in the browser.
 
-                if (_useHtml && !noResultsData)
-                {
-                    Process.Start(resultsPath);
+                    if (_useHtml && !noResultsData)
+                    {
+                        Process.Start(resultsPath);
+                    }
                 }
-            }
 
-            return new TestResult(processOutput.ExitCode == 0, assemblyName, span, errorOutput.ToString());
+                return new TestResult(processOutput.ExitCode == 0, assemblyName, span, errorOutput.ToString());
+            }
+            catch (Exception ex)
+            {
+                throw new Exception($"Unable to run {assemblyPath}", ex);
+            }
         }
 
         private static void DeleteFile(string filePath)