StandardOutput/StandardError of launched process is not shown

[mxschmitt]

Describe the bug

When launching a process StandardOutput and StandardError is not shown. When launching the same code via a new console app it works.

Steps To Reproduce

Provide the steps to reproduce the behavior:

1. Create a new MSTest project via: dotnet new mstest -n PlaywrightTests; cd PlaywrightTests
2. Modify the UnitTest1.cs file and put the following into it:

using System.Diagnostics;

namespace PlaywrightTests;

[TestClass]
public class UnitTest1
{
    [TestMethod]
    public void TestMethod1()
    {
        var process = new Process();
        process.StartInfo.FileName = "C:\\Program Files\\PowerShell\\7\\pwsh.exe";
        process.StartInfo.Arguments = "-c \"echo 'hello from stdout'; Write-Error 'hello from stderr'\"";
        process.Start();
        process.WaitForExit();
    }
}

3. Run the test via dotnet test

Expected behavior

Output shown

Actual behavior

Nothing shown

Additional context

Affected project: https://github.com/microsoft/playwright-dotnet

When doing the same via dotnet new console it works and gets displayed.

[engyebrahim]

Hi @mxschmitt thanks for reporting that.
I managed to reproduce and marked it as bug. we will work on it soon.

[MarcoRossignoli]

I did some tests with our new test runner https://learn.microsoft.com/dotnet/core/testing/unit-testing-mstest-runner-intro where we're sure we're not capturing the console output and looks like MSTest is not the culprit here but the VSTest platform that's capturing the output.

[TestClass]
public class TestClass
{
    [TestMethod]
    public void Test1()
    {
        var process = new Process();
        process.StartInfo.FileName = "C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe";
        process.StartInfo.Arguments = "-c \"echo 'hello from stdout'; Write-Error 'hello from stderr'\"";
        process.Start();
        process.WaitForExit();
    }
}