Add --ansi option to force Ansi output

[powercode]

Summary

Add the complement to --no-ansi, that forces --ansi output, even if output is redirected.

Background and Motivation

When running the tests from a PowerShell script, I may want to display the test output but not have it as output from the PowerShell function.

mytest.exe | Out-Host
if ($LASTEXITCODE){
   throw "test failed"
}

This removes all coloring from the output, even though it's logically equivalent to passing it directly to the terminal for display.

Proposed Feature

Add --ansi parameter that forces ansi output, regardless of redirection. Let the user decide.

Alternative Designs

Always output ansi unless the user explicitly uses --no-ansi. That has the drawback of potentially breaking existing scripts.

[Evangelink]

It's probably a quick and easy update so I don't see why not! Thanks for the suggestion @powercode.

cc @mariam-abdulla as it might require some porting to dotnet test.

[bradwilson]

Forcing ANSI should only be done if you know if you're running inside of a terminal that can handle it. The standard console host (CONHOST), for example, does not support ANSI:

[Evangelink]

@bradwilson I agree and that's why this is not the default behavior. The default is trying to auto-detect if we can use ansi or not. We then have flags to force using or not using ANSI.

[nohwnd]

moving to 3.10, I think we need a better design for this, having --ansi and --no-ansi, leads to many combinations with similar options like --no-color and so on.

[Evangelink]

@nohwnd what about --ansi <auto|enable|disable>, --color <enable|disable> (this one may need some deps on ansi?).

I think gradle (java) had something interesting where cli has only part of the commands, for extra granularity you needed the config file. Maybe a similar design could help so we don't have to support it all as CLI.

[bradwilson]

FWIW, xUnit.net uses on and off for switches in MTP. https://github.com/xunit/xunit/blob/main/src/xunit.v3.runner.inproc.console/TestingPlatform/CommandLineOptionsProvider.cs

[nohwnd]

yes those are all good options, terminal logger does something similar with handling auto, and on/off true/false 0/1.

Then it is just question of deprecating no-ansi no-color or not, but we cannot do that right away anyway.

[Youssef1313]

@nohwnd I moved to "Future" milestone. But feel free to move to "2.0.0" as a breaking change (and if you did, please add it to https://github.com/microsoft/testfx/issues/5762 and add the "Breaking !!" label)

[Evangelink]

Given the v2 was missed, what about introducing the new API and deprecating the old ones (but keeping them working)? It feels like something we can implement quickly.