Ruby on Rails
Pin Ruby for an existing Rails app from its .ruby-version file, and run the app's Bundler and Rails commands as tasks. The recipe assumes Gemfile, Gemfile.lock, bin/rails and .ruby-version, with RuboCop in the development group.
Use the app's .ruby-version
[settings]
idiomatic_version_file_enable_tools = ["ruby"]
[tasks.install]
description = "Install gem dependencies"
run = "bundle install"
[tasks.server]
description = "Start the Rails server"
alias = "s"
run = "bin/rails server"
[tasks.test]
description = "Run tests"
alias = "t"
run = "bin/rails test"
[tasks.lint]
description = "Run RuboCop"
alias = "l"
run = "bundle exec rubocop"The setting makes mise read the app's .ruby-version (a leading ruby-, as in ruby-3.4.7, is ignored), so the version stays in one file that other Ruby tools also read. Because the setting is in the project's mise.toml, teammates and CI read .ruby-version too. If the app has no .ruby-version, set ruby = "4.0" under [tools] instead. See version files for the other files mise can read.
Run mise run install after cloning; mise installs the Ruby version first if it is missing. Then run mise run test or mise run server. The binstubs and bundle exec load the app's bundle, so Rails and RuboCop run at their locked versions. Database setup stays with the app's own bin/setup or bin/rails db:prepare.
mise installs precompiled Ruby where a build exists for your platform. For source builds and the system libraries they need, see compiling with ruby-build.
To run bundle install only when Gemfile or Gemfile.lock changes, use the experimental [deps.bundler] provider instead of the install task.