Support asdf .tool-versions File

[Kurt-von-Laven]

Description:
actions/setup-node, actions/setup-python, ruby/setup-ruby, and erlef/setup-beam all support reading from .tool-versions. It would be helpful to have such support consistently in all official setup actions.

Justification:
With over 18k stars and over 400 plugins, asdf is the most popular multi-language runtime manager. .tool-versions is becoming the de facto standard for pinning runtimes, package managers, and other development tools as most other standardized file formats support only one tool.

Are you willing to submit a PR?
No

[nikolai-laevskii]

Thank you for making a feature request! We will investigate possibilities for implementation and come back with an update.

[Kurt-von-Laven]

In case it's helpful either for implementation purposes or for others wanting this feature, here is how we used to read the Python version out of .tool-versions. One would of course want to replace python with dotnet-core in this case, yielding something like the following Bash:

asdf_version="$(grep --perl-regexp --only-matching '(?<=dotnet-core\s).*' .tool-versions)"