private static void WriteException(this StandardStreamWriter output, Exception exception, int indentLevel)
{
Type exceptionType = exception.GetType();
string indentationShared = new string(' ', 4 * indentLevel);
string indentationLocal = new string(' ', 2);
// Fully qualified exception type
output.Write(indentationShared);
output.WithForegroundColor(ConsoleColor.DarkGray, (o) =>
{
o.Write(exceptionType.Namespace);
o.Write('.');
});
output.WithForegroundColor(ConsoleColor.White, (o) => o.Write(exceptionType.Name));
output.Write(": ");
// Exception message
output.WithForegroundColor(ConsoleColor.Red, (o) => o.WriteLine(exception.Message));
// Recurse into inner exceptions
if (exception.InnerException is not null)
{
output.WriteException(exception.InnerException, indentLevel + 1);
}
if (exception.StackTrace is null)
{
return;
}
// Try to parse and pretty-print the stack trace
try
{
foreach (StackFrame stackFrame in StackTraceParser.ParseMany(exception.StackTrace))
{
output.Write(indentationShared);
output.Write(indentationLocal);
output.WithForegroundColor(ConsoleColor.Green, (o) => o.Write("at "));
// "Typin.Demo.Commands.BookAddCommand."
output.WithForegroundColor(ConsoleColor.DarkGray, (o) =>
{
o.Write(stackFrame.ParentType);
o.Write('.');
});
// "ExecuteAsync"
output.WithForegroundColor(ConsoleColor.Yellow, (o) => o.Write(stackFrame.MethodName));
output.Write('(');
for (int i = 0; i < stackFrame.Parameters.Count; ++i)
{
StackFrameParameter parameter = stackFrame.Parameters[i];
// "IConsole"
output.WithForegroundColor(ConsoleColor.Blue, (o) => o.Write(parameter.Type));
if (!string.IsNullOrWhiteSpace(parameter.Name))
{
output.Write(' ');
// "console"
output.WithForegroundColor(ConsoleColor.White, (o) => o.Write(parameter.Name));
}
// Separator
if (stackFrame.Parameters.Count > 1 && i < stackFrame.Parameters.Count - 1)
{
output.Write(", ");
}
}
output.Write(") ");
// Location
if (!string.IsNullOrWhiteSpace(stackFrame.FilePath))
{
output.WithForegroundColor(ConsoleColor.Magenta, (o) => o.Write("in"));
output.WriteLine();
output.Write(indentationShared);
output.Write(indentationLocal);
output.Write(indentationLocal);
// "C:\Projects\Typin\Typin.Demo\Commands\"
var stackFrameDirectoryPath = Path.GetDirectoryName(stackFrame.FilePath);
output.WithForegroundColor(ConsoleColor.DarkGray, (o) =>
{
o.Write(stackFrameDirectoryPath);
o.Write(Path.DirectorySeparatorChar);
});
// "BookAddCommand.cs"
string stackFrameFileName = Path.GetFileName(stackFrame.FilePath) ?? string.Empty;
output.WithForegroundColor(ConsoleColor.Cyan, (o) => o.Write(stackFrameFileName));
if (!string.IsNullOrWhiteSpace(stackFrame.LineNumber))
{
output.Write(':');
// "35"
output.WithForegroundColor(ConsoleColor.Magenta, (o) => o.Write(stackFrame.LineNumber));
}
}
output.WriteLine();
}
}
// If any point of parsing has failed - print the stack trace without any formatting
catch
{
output.WriteLine(exception.StackTrace);
}
}
/// <summary>
/// Writes formatted exception to output stream (stdout or stderr).
/// </summary>
public static void WriteException(this StandardStreamWriter output, Exception exception)
{
output.WriteException(exception, 0);
}