Exit codes and errors

Validation

By default, ExecuteAsync and ExecuteBufferedAsync throw a ProcessExecutionException when the process exits with a non-zero exit code. WithValidation changes the rules:

// Default: throws ProcessExecutionException if exit code is non-zero
try
{
    await ProcessWrapper.Create("false")
        .ExecuteAsync();
}
catch (ProcessExecutionException ex)
{
    Console.WriteLine($"Process failed with exit code {ex.ExitCode}");
}

// Disable validation
var result = await ProcessWrapper.Create("false")
    .WithValidation(ProcessValidationMode.None)
    .ExecuteAsync();
int exitCode = result.ExitCode;
bool isSuccess = result.ExitCode.IsSuccess;

// Fail on stderr output as well
await ProcessWrapper.Create("my-command")
    .WithValidation(ProcessValidationMode.FailIfNonZeroExitCode | ProcessValidationMode.FailIfStdError)
    .ExecuteAsync();

// Control command details included in exception messages and ProcessResult.ToString()
ProcessWrapper.DefaultLogVerbosity = ProcessLogVerbosity.IncludeProcessPath;

await ProcessWrapper.Create("my-command")
    .WithArguments("--token", "secret")
    .WithLogVerbosity(ProcessLogVerbosity.IncludeProcessPath | ProcessLogVerbosity.IncludeArguments)
    .ExecuteAsync();

The values are flags: combine them with |. The exception is thrown when you await the process, after it exited and all its output was read.

The exception

var command = ProcessWrapper.Create("my-command")
    .WithProcessFactory(new FakeProcessFactory(FakeProcess.Create(exitCode: 1)));

var exception = await Assert.ThrowsAsync<ProcessExecutionException>(async () => await command.ExecuteAsync());
Assert.Equal(1, exception.ExitCode.Value);
Assert.StartsWith("Process exited with code 1.", exception.Message);

• For an exit code failure, ExitCode holds the exit code, and the message starts with Process exited with code.
• For output on standard error, the message starts with Process wrote to standard error.
• The message ends with the command, as allowed by the log verbosity.

Read the exit code

With ProcessValidationMode.None, read the exit code from the result:

var result = await ProcessWrapper.Create("my-command")
    .WithProcessFactory(new FakeProcessFactory(FakeProcess.Create(exitCode: 3)))
    .WithValidation(ProcessValidationMode.None)
    .ExecuteAsync();

Assert.False(result.ExitCode.IsSuccess);
Assert.True(result.ExitCode.IsAnyOf(2, 3));

// ProcessExitCode converts implicitly to int
int exitCode = result.ExitCode;
Assert.Equal(3, exitCode);

ProcessExitCode wraps the value: IsSuccess is true for 0, IsAnyOf checks a list of expected values, Value and the implicit conversion to int return the number.

What messages show

Exception messages and ProcessResult.ToString include the command. Arguments can contain secrets, such as tokens or passwords, so by default only the path of the executable is shown. ProcessLogVerbosity chooses what is shown:

Combine IncludeProcessPath | IncludeArguments to show the whole command line. Set it per command with WithLogVerbosity, or for all commands with ProcessWrapper.DefaultLogVerbosity. The default applies to the ProcessWrapper instances created after you set it.

ProcessWrapper.ToString is not affected: it always returns the whole command line. See Configuring the process.