Console.WriteLine calls during dotnet test are not emitted to the console on Windows

[livarcocc]

From @jonsequitur on December 15, 2016 19:10

Steps to reproduce

• Add a Console.WriteLine call in a test, .e.g GivenThatIWantToMigrateTestApps.ItMigratesRootProjectAndReferences
• On Windows, dotnet test --test-case-filter "FullyQualifiedName=Microsoft.DotNet.Migration.Tests.GivenThatIWantToMigrateTestApps.ItMigratesRootProjectAndR eferences"

Expected behavior

The string passed to Console.WriteLine appears in console output.

Actual behavior

C:\dev\github\cli\test\dotnet-migrate.Tests [rel/1.0.0 ↓ +0 ~2 -0 !]> dotnet test --test-case-filter "FullyQualifiedName=Microsoft.DotNet.Migration.Tests.GivenThatIWantToMigrateTestApps.ItMigratesRootProjectAndR
eferences"
Build started, please wait...
Build completed.

Test run for C:\dev\github\cli\test\dotnet-migrate.Tests\bin\Debug\netcoreapp1.0\dotnet-migrate.Tests.dll(.NETCoreApp,Version=v1.0)
Microsoft (R) Test Execution Command Line Tool Version 15.0.0.0
Copyright (c) Microsoft Corporation.  All rights reserved.

Starting test execution, please wait...
Passed   Microsoft.DotNet.Migration.Tests.GivenThatIWantToMigrateTestApps.ItMigratesRootProjectAndReferences(projectName: "ProjectB", expectedProjects: "ProjectB,ProjectC,ProjectD,ProjectE")
Passed   Microsoft.DotNet.Migration.Tests.GivenThatIWantToMigrateTestApps.ItMigratesRootProjectAndReferences(projectName: "ProjectA", expectedProjects: "ProjectA,ProjectB,ProjectC,ProjectD,ProjectE")
Passed   Microsoft.DotNet.Migration.Tests.GivenThatIWantToMigrateTestApps.ItMigratesRootProjectAndReferences(projectName: "ProjectC", expectedProjects: "ProjectC,ProjectD,ProjectE")
Passed   Microsoft.DotNet.Migration.Tests.GivenThatIWantToMigrateTestApps.ItMigratesRootProjectAndReferences(projectName: "ProjectE", expectedProjects: "ProjectE")
Passed   Microsoft.DotNet.Migration.Tests.GivenThatIWantToMigrateTestApps.ItMigratesRootProjectAndReferences(projectName: "ProjectD", expectedProjects: "ProjectD")

Total tests: 5. Passed: 5. Failed: 0. Skipped: 0.
Test Run Successful.
Test execution time: 32.2825 Seconds

Environment data

dotnet --info output:

.NET Command Line Tools (1.0.0-preview5-004253)

Product Information:
Version: 1.0.0-preview5-004253
Commit SHA-1 hash: 0caae96daf

Runtime Environment:
OS Name: Windows
OS Version: 10.0.14393
OS Platform: Windows
RID: win10-x64
Base Path: C:\dev\github\cli\artifacts\win10-x64\stage2\sdk\1.0.0-preview5-004253

Copied from original issue: dotnet/cli#5033

[livarcocc]

From @krwq on January 5, 2017 23:46

@jonsequitur You should probably be using Xunit's ITestOutputHelper. making Console.WriteLine forward to that might be slightly harder

[livarcocc]

From @jonsequitur on January 6, 2017 4:35

The issue that I was seeing was that this works on OS X but not on Windows.

[livarcocc]

I am seeing that too on windows. None of the Console.WriteLine from my tests gets printed out. We should not ask users to use special APIs to print to the console.

@codito @Faizan2304 Can you guys take a look?

I think we should move this bug to the vstest repo.

[codito]

I think this should be handled by adapters at some level. MSTest for instance captures and sends the console outputs to the runner, I think we are including them in trx logger, but not in the console. We can start showing them in console. cc: @Faizan2304

There were a few requests to capture console output in xunit:
https://xunit.github.io/docs/capturing-output.html suggests to use IOutputHelper
xunit/xunit#1141

[Faizan2304]

Fixed!!

[zwcloud]

@Faizan2304 Is it fixed in Visual Studio Community 2017 Version 15.2 (26430.15) Release? I still cannot get the output in the output window or the test explorer. I'm using xunit.

[rogusdev]

I also still do not see test output and would love to, please.

From dotnet test output:

Test ...Tests\bin\Debug\netcoreapp2.0\~.dll(.NETCoreApp,Version=v2.0)
Microsoft (R) Test Execution Command Line Tool Version 15.3.0-preview-20170703-02

and in csproj:

    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.3.0-preview-20170628-02" />
    <PackageReference Include="xunit" Version="2.2.0" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />

(I am using preview version of VS and latest dotnet core from github)

[Faizan2304]

Sorry for the late reply. I missed this thread.
@zwcloud: We have fixed it in vstest.console of version v15.3.0-preview-20170517-02 and it is part of Visual studio 2017 Update3 preview3. Please see below answer to see test output with xunit.

@rogusdev : How are you writing output from test method? Is it Console.WriteLine ?
If yes then it seems xunit doesn't support that.
There were a few requests to capture console output in xunit:
https://xunit.github.io/docs/capturing-output.html suggests to use IOutputHelper
xunit/xunit#1141

[zwcloud]

@Faizan2304

Is it Console.WriteLine ?
If yes then it seems xunit doesn't support that.

Yes. But @bradwilson said in xunit#1141

There is no way to see that output with dotnet test because of limitations in the VSTest runner.

We do not capture stdout (users are free to use that if they so choose). Our output capture system pushes that information into the test result rather than to stdout. The TRX report may or may not generate reports which include "output" results (I don't personally know, since I have no knowledge of this format), but today there's no simple way today to get this output from dotnet test directly on the console.

Visual Studio's UI, on the other hand, offers ready access to "output", which is where this information is captured.

So.. could you fix or change the behaviour of VSTest runner to remove the limitaion?

[Faizan2304]

@zwcloud:
We display what adapter sends in TestResult.Message Code here And here

Its the responsibility of adapter to fill console.WriteLine message in TestResult.Message.

But as you can see, @bradwilson said in xunit#1141 that they are not capturing console output to test result

Users will use ITestOutputHelper to write output. That's what ends up in ITestResultMessage.Output. We do not capture any device like console, debug, or tracing.

In this case you have to follow this article. xunit is suggesting to use IOutputHelper to log your message.

[evil-shrike]

Why the issue is closed if there is still no console output in tests?

It's kinda strange to have console test runner which doesn't show console output.