Prettify the the diagnostic file content

src/NServiceBus.Core/Hosting/StartupDiagnostics/HostStartupDiagnosticsWriterFactory.cs

@@ -55,7 +55,12 @@ static Func<string, Task> BuildDefaultDiagnosticsWriter(HostingComponent.Configu
  var startupDiagnosticsFileName = $"{configuration.EndpointName}-configuration.txt";
  var startupDiagnosticsFilePath = Path.Combine(diagnosticsRootPath, startupDiagnosticsFileName);
 
- return data => AsyncFile.WriteText(startupDiagnosticsFilePath, data);
+
+ return data =>
+ {
+ var prettied = JsonPrettyPrinter.Print(data); 
+ return AsyncFile.WriteText(startupDiagnosticsFilePath, prettied);
+ };
  }
 
  static readonly ILog logger = LogManager.GetLogger<HostStartupDiagnosticsWriter>();

src/NServiceBus.Core/Hosting/StartupDiagnostics/JsonPrettyPrinter.cs

@@ -0,0 +1,72 @@
+namespace NServiceBus
+{
+ using System.Text;
+
+ static class JsonPrettyPrinter
+ {
+ const string LINE_INDENT = " ";
+
+ internal static string Print(string input)
+ {
+ var builder = new StringBuilder(input.Length);
+ var quoted = false;
+ var indent = 0;
+
+ for (var i = 0; i < input.Length; i++)
+ {
+ var ch = input[i];
+ switch (ch)
+ {
+ case '{':
+ case '[':
+ builder.Append(ch);
+ if (!quoted) PrintIndent(builder, ++indent);
+ break;
+ case '}':
+ case ']':
+ if(!quoted) PrintIndent(builder, --indent);
+ builder.Append(ch);
+ break;
+ case '"':
+ builder.Append(ch);
+ var escaped = IsEscaped(input, i);
+ if (!escaped) quoted = !quoted;
+ break;
+ case ',':
+ builder.Append(ch);
+ if (!quoted) PrintIndent(builder, indent);
+ break;
+ case ':':
+ builder.Append(ch);
+ if (!quoted) builder.Append(" ");
+ break;
+ default:
+ builder.Append(ch);
+ break;
+ }
+ }
+
+ return builder.ToString();
+ }
+
+ static bool IsEscaped(string input, int i)
+ {
+ var escaped = false;
+ var index = i;
+ while (index > 0 && input[--index] == '\\')
+ {
+ escaped = !escaped;
+ }
+ return escaped;
+ }
+
+ static void PrintIndent(StringBuilder sb, int indent)
+ {
+ sb.AppendLine();
+ for (var i = 0; i <= indent; i++)
+ {
+ sb.Append(LINE_INDENT);
+ }
+ }
+ }
+}