Add support for mise.toml (#700)

Co-authored-by: Benoit Daloze <[email protected]>

README.md

@@ -74,7 +74,7 @@ jobs:
     - uses: actions/checkout@v4
     - uses: ruby/setup-ruby@v1
       with:
-        ruby-version: '3.3' # Not needed with a `.ruby-version` or `.tool-versions`
+        ruby-version: '3.3' # Not needed with a `.ruby-version`, `.tool-versions` or `mise.toml`
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically
     - run: bundle exec rake
 ```
@@ -139,11 +139,12 @@ and the [condition and expression syntax](https://help.github.com/en/actions/ref
 * engine only like `ruby` and `truffleruby`, uses the latest stable release of that implementation
 * `.ruby-version` reads from the project's `.ruby-version` file
 * `.tool-versions` reads from the project's `.tool-versions` file
-* If the `ruby-version` input is not specified, `.ruby-version` is tried first, followed by `.tool-versions`
+* `mise.toml` reads from the project's `mise.toml` file
+* If the `ruby-version` input is not specified, `.ruby-version` is tried first, followed by `.tool-versions`, followed by `mise.toml`
 
 ### Working Directory
 
-The `working-directory` input can be set to resolve `.ruby-version`, `.tool-versions` and `Gemfile.lock`
+The `working-directory` input can be set to resolve `.ruby-version`, `.tool-versions`, `mise.toml` and `Gemfile.lock`
 if they are not at the root of the repository, see [action.yml](action.yml) for details.
 
 ### RubyGems

action.yml

@@ -6,7 +6,7 @@ branding:
   icon: download
 inputs:
   ruby-version:
-    description: 'Engine and version to use, see the syntax in the README. Reads from .ruby-version or .tool-versions if unset.'
+    description: 'Engine and version to use, see the syntax in the README. Reads from .ruby-version, .tool-versions or mise.toml if unset.'
     default: 'default'
   rubygems:
     description: |
@@ -26,7 +26,7 @@ inputs:
     description: 'Run "bundle install", and cache the result automatically. Either true or false.'
     default: 'false'
   working-directory:
-    description: 'The working directory to use for resolving paths for .ruby-version, .tool-versions and Gemfile.lock.'
+    description: 'The working directory to use for resolving paths for .ruby-version, .tool-versions, mise.toml and Gemfile.lock.'
   cache-version:
     description: |
       Arbitrary string that will be added to the cache key of the bundler cache. Set or change it if you need

index.js

@@ -117,6 +117,8 @@ function parseRubyEngineAndVersion(rubyVersion) {
       rubyVersion = '.ruby-version'
     } else if (fs.existsSync('.tool-versions')) {
       rubyVersion = '.tool-versions'
+    } else if (fs.existsSync('mise.toml')) {
+      rubyVersion = 'mise.toml'
     } else {
       throw new Error('input ruby-version needs to be specified if no .ruby-version or .tool-versions file exists')
     }
@@ -130,6 +132,11 @@ function parseRubyEngineAndVersion(rubyVersion) {
     const rubyLine = toolVersions.split(/\r?\n/).filter(e => /^ruby\s/.test(e))[0]
     rubyVersion = rubyLine.match(/^ruby\s+(.+)$/)[1]
     console.log(`Using ${rubyVersion} as input from file .tool-versions`)
+  } else if (rubyVersion === 'mise.toml') { // Read from mise.toml
+    const toolVersions = fs.readFileSync('mise.toml', 'utf8').trim()
+    const rubyLine = toolVersions.split(/\r?\n/).filter(e => /^ruby\s*=\s*/.test(e))[0]
+    rubyVersion = rubyLine.match(/^ruby\s*=\s*['"](.+)['"]$/)[1]
+    console.log(`Using ${rubyVersion} as input from file mise.toml`)
   }
 
   let engine, version