Public ReadOnly Property StandardInput As TextWriter

public TextWriter StandardInput {get;}

string tempfile = Path.GetTempFileName();
try
{
    ProcessRunner runner = new ProcessRunner("cmd.exe");

    runner.Start();
    runner.StandardInput.WriteLine("ECHO Hello > " + tempfile);
    runner.StandardInput.WriteLine("EXIT");

    Assert.IsTrue(runner.WaitForExit(TimeSpan.FromMinutes(1)));
    Assert.AreEqual(0, runner.ExitCode);

    string output = File.ReadAllText(tempfile).Trim();
    Assert.AreEqual("Hello", output);
}
finally
{ File.Delete(tempfile); }

Dim tempfile As String = Path.GetTempFileName()
Try
    Dim runner As New ProcessRunner("cmd.exe")

    runner.Start()
    runner.StandardInput.WriteLine("ECHO Hello > " + tempfile)
    runner.StandardInput.WriteLine("EXIT")

    Assert.IsTrue(runner.WaitForExit(TimeSpan.FromMinutes(1)))
    Assert.AreEqual(0, runner.ExitCode)

    Dim output As String = File.ReadAllText(tempfile).Trim()
    Assert.AreEqual("Hello", output)
Finally
    File.Delete(tempfile)
End Try