Nix yarn binstub

[gauravtiwari]

Lets just use yarn executable directly instead of using the same executable through a binstub to make things simple across all platforms. Since we check for yarn executable presence and version before installing Webpacker this shouldn't be a problem.

Companion PR #363

[gauravtiwari]

Thanks for reviewing 😄

[swrobel]

Rails 5.1 task yarn:install still expects ./bin/yarn to exist. What is the recommended solution? Currently rake assets:precompile fails with error Command "webpack" not found.

[gauravtiwari]

@swrobel I think we change this behaviour in Rails as well. Could you open a ticket there please?

[rmacklin]

I actually liked the flexibility provided by having this binstub. It allows application owners to change the binstub's contents and webpacker will invoke the changed version.

For example, one use case is to change the binstub to be a standalone copy of yarn (which is distributed with each release: https://github.com/yarnpkg/yarn/releases). Doing so ensures that all developers, as well as CI and production machines are using the same exact yarn version, which makes it impossible for issues to arise due to one user/machine using a different yarn version than another user/machine. And since yarn is contained in the repo, upgrading it is trivial, and automatically applies to all developers when they git pull. These are very nice properties to have.

Would you be open to accepting a PR to add back the binstub?