CODEWITHSUNDEEP
c#consolemstestwatin
Julian
Julian

Reputation: 20324

How to write to Console.Out during execution of an MSTest test

Context:
We have some users reporting issues with a file upload feature in our web application. It only happens occasionally and without any special pattern. We have been trying to figure it out for a long time, adding debug information anywhere we can think it might help, crawling the logs etc, but we have not been able to reproduce or figure it out.

Problem:
I'm now trying to reproduce this by using MSTest and WatiN to repeat the operation that is supposed to fail a large number of times (several hundreds). Just to have a clue about how far in the loop the test has gotten, I want to print something like:

Console.WriteLine(String.Format("Uploaded file, attempt {0} of {1}", i, maxUploads));

This does however not appear in the Output window. Now I know that you'll get the console output in the test results (as well as what you output from Debug.Writeline etc), but this is not available until after the test has finished. And since my test with hundreds of repetitions could take quite some time, I'd like to know how far it has gotten.

Question:
Is there a way I can get the console output in the Output window during test execution?

Upvotes: 135

Views: 150773

Answers (6)

riezebosch
riezebosch

Reputation: 2026

Update: Load Tests functionality is deprecated.

--- original answer
You better setup a single test and create a performance test from this test. This way you can monitor the progress using the default tool set.

Upvotes: -3

JJS
JJS

Reputation: 6678

It's not the console, but it is in the output panel.

public class Test
{
 public TestContext TestContext { get; set; }

 [TestMethod]
 public void Foo()
 {
   TestContext.WriteLine("Hello World");
 }
}

Upvotes: 5

Andras Zoltan
Andras Zoltan

Reputation: 42363

The Console output is not appearing is because the backend code is not running in the context of the test.

You're probably better off using Trace.WriteLine (In System.Diagnostics) and then adding a trace listener which writes to a file.

This topic from MSDN shows a way of doing this.

According to Marty Neal's and Dave Anderson's comments:

using System;
using System.Diagnostics;

...

Trace.Listeners.Add(new TextWriterTraceListener(Console.Out));
// or Trace.Listeners.Add(new ConsoleTraceListener());
Trace.WriteLine("Hello World");

Upvotes: 125

Gökhan Kurt
Gökhan Kurt

Reputation: 531

I had the same issue and I was "Running" the tests. If I instead "Debug" the tests the Debug output shows just fine like all others Trace and Console. I don't know though how to see the output if you "Run" the tests.

Upvotes: 6

chaliasos
chaliasos

Reputation: 9793

Use the Debug.WriteLine. This will display your message in the Output window immediately. The only restriction is that you must run your test in Debug mode.

[TestMethod]
public void TestMethod1()
{
    Debug.WriteLine("Time {0}", DateTime.Now);
    System.Threading.Thread.Sleep(30000);
    Debug.WriteLine("Time {0}", DateTime.Now);
}

Output

enter image description here

Upvotes: 86

SimplyKnownAsG
SimplyKnownAsG

Reputation: 934

I found a solution of my own. I know that Andras answer is probably the most consistent with MSTEST, but I didn't feel like refactoring my code.

[TestMethod]
public void OneIsOne()
{
    using (ConsoleRedirector cr = new ConsoleRedirector())
    {
        Assert.IsFalse(cr.ToString().Contains("New text"));
        /* call some method that writes "New text" to stdout */
        Assert.IsTrue(cr.ToString().Contains("New text"));
    }
}

The disposable ConsoleRedirector is defined as:

internal class ConsoleRedirector : IDisposable
{
    private StringWriter _consoleOutput = new StringWriter();
    private TextWriter _originalConsoleOutput;
    public ConsoleRedirector()
    {
        this._originalConsoleOutput = Console.Out;
        Console.SetOut(_consoleOutput);
    }
    public void Dispose()
    {
        Console.SetOut(_originalConsoleOutput);
        Console.Write(this.ToString());
        this._consoleOutput.Dispose();
    }
    public override string ToString()
    {
        return this._consoleOutput.ToString();
    }
}

Upvotes: 16

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