Deterministic tool versions across environments with Mise

A common source of headaches in development teams are issues coming from multiple versions of tools used across environments. The “it works for me” is often followed by a “Which version of X are you using?”. It happens because it’s the developers’ responsibility to manage their shell and the tools that are active in it through the $PATH environment variable, and CI environments, like GitHub Actions, offer their building block to manage the tools. For example, setup-ruby takes care of installing Ruby in the GitHub Actions environment. It uses the convention of using the .ruby-version file to indicate the Ruby version to use, but what if locally, the developers are using a version management tool that doesn’t follow the convention? Or what if they decide to manage the installation globally through a tool like Homebrew.

This developer experience is far from ideal. Some organizations decide to ignore the problem, perhaps because they are not aware of it. Others like Shopify have an entire team dedicated to solving it, which comes at a huge cost for the business. What if you could solve the problem with little to no effort and cost? That’s what Mise is for. We are making it the default installation method for Tuist, and also evangelizing it to the Swift community, where project setups have multiple tooling requirements. For example, Ruby to run Fastlane, SwiftLint to lint the Swift code, or Sourcery to do meta-programming. Imagine managing these tools without a unified method that’s consistent throughout the local and CI environments…

How does it work? Easy. Once you’ve installed Mise and added the hook to your shell, you can create a .mise.toml file at the root of your project:

[tools]
tuist = "3.39.3"
swiftlint = "0.54.0"
sourcery = "2.1.3"
ruby = "3.3.0"

Then you run mise install and Mise will install and activate the right version of the tools. Note the “activate” part. Mise ensures the right version is activated when you are in that directory or any sub-directory. That prevents globally-installed versions from taking precedence over the ones specified in the .mise.toml file.

And what about CI? You can also use Mise. If you are using a CI provider like GitHub Actions, the process is very simplified through a custom action, mise-action:

on:
  pull_request:
    branches:
      - main
  push:
    branches:
      - main
jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: jdx/mise-action@v2

Mise is by far one of the best tools I’ve used for configuring and activate my environment for a project. It’s one of those tools that you install and forget about it. @jdx, the creator of the tool, and a developer very passionate about creating terminal tools, has done a fantastic craftsmanship job with it. I’d recommend to give it a try. You won’t regret it.