feat: fall back to locally-installed tailwindcss executables

[flavorjones]

If a user has installed the ruby platform gem, but has the tailwindcss executable installed in their path, then we should fall back to that.

Closes #224

[flavorjones]

@TheNeikos do you want to give this branch a try and let me know if it works for you?

Here's how you can try it out:

• checkout this branch (flavorjones-fallback-to-manually-installed)
• bundle install && bundle exec rake gem:ruby
• gem install --local pkg/tailwindcss-rails-2.0.21.gem

[TheNeikos]

Sadly it still does not work :c

This is because you are explicitly checking for wrapper scripts and ignore them? I don't think that is necessary, since users can decide themselves how they want their executables to be called.

In my case for example, and quite usual for NixOS, tailwindcss is a wrapper script that sets a bunch of env variables before calling the actual binary.

[flavorjones]

Can you help me understand what "does not work" looks like for you? Can you give me more information about how it doesn't work?

I chose to ignore wrapper scripts because Rubygems will install a tailwindcss wrapper script that's in the user's path, and so I need some mechanism to avoid infinite recursion (calling the tailwindcss rubygems shim, which calls this gem's tailwindcss script, which then call the rubygems shim again). If you have any ideas on how to do this in a robust manner that works on your system, please let me know.

[flavorjones]

Maybe I'm overthinking this, would a suitable alternative be to set an environment variable to the path of your "real" tailwindcss installation?

Something like this in your .envrc for example:

TAILWINDCSS_RAILS_LOCAL_PATH=/path/to/nix/installation/bin/tailwindcss

Would that solve your use case?

[TheNeikos]

Can you help me understand what "does not work" looks like for you? Can you give me more information about how it doesn't work?

I chose to ignore wrapper scripts because Rubygems will install a tailwindcss wrapper script that's in the user's path, and so I need some mechanism to avoid infinite recursion (calling the tailwindcss rubygems shim, which calls this gem's tailwindcss script, which then call the rubygems shim again). If you have any ideas on how to do this in a robust manner that works on your system, please let me know.

Sorry I didn't go into more detail. But basically, same behaviour as before. It just tells me that I need to have it installed (since it is just a wrapper script I have in my PATH, I assume that whatever it does find, it just skips it).

My first question would be, why does the rubygems shim have the same name? Could it be removed/renamed?

Would that solve your use case?

That would 100% solve it! I can easily set things like that.

[flavorjones]

why does the rubygems shim have the same name

For the same reason that Nix's shim has the same name?

That would 100% solve it

OK, I'll overhaul this PR with that approach.

[TheNeikos]

For the same reason that Nix's shim has the same name?

Haha, fair enough! I just wouldn't expect a rubygem to install an executable with the same name as the one it tries to catch only to say that it is not installed!

In the NixOS case its to make sure tailwind can find all the plugins it needs and is more of a redirect to the actual executable.

[piperswe]

Another Nix user here: this is the main blocker for me moving my app's build process entirely under Nix, is there anything I can do to help move it along?

[piperswe]

I just ended up creating a new PR (#259) with the environment variable override approach

[nanaya]

fwiw, it's also a problem for people running on "unsupported" platform (freebsd etc). I just override the whole function for now. Actual tailwindcss can be installed no problem on platforms with node using npm/yarn.

# config/initializers/00tailwind_freebsd.rb
module Tailwindcss
  module Commands
    def self.executable(*)
      File.expand_path(File.join(__dir__, "..", "..", "node_modules", ".bin", "tailwindcss"))
    end
  end
end

[flavorjones]

I've updated this branch with an environment-variable-setting approach.