Add a new input to optionally update RubyGems

Author: deivid-rodriguez

.github/workflows/test.yml

@@ -112,6 +112,28 @@ jobs:
       if: startsWith(matrix.os, 'windows') && startsWith(matrix.ruby, 'jruby')
       run: gem install sassc
 
+  testLatestRubygemsVersion:
+    name: "Test rubygems input set to latest upgrades the default RubyGems version"
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: ./
+      with:
+        ruby-version: 2.6
+        rubygems: latest
+    - run: ruby -e "exit(Gem.rubygems_version > Gem::Version.new('3.0.3'))"
+
+  testFixedRubygemsVersion:
+    name: "Test rubygems input set to a fixed version upgrades RubyGems to that versoin"
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: ./
+      with:
+        ruby-version: 2.6
+        rubygems: 3.3.5
+    - run: gem --version | grep -F "3.3.5"
+
   testExactBundlerVersion:
     name: "Test with an exact Bundler version"
     runs-on: ubuntu-latest

action.yml

@@ -9,6 +9,13 @@ inputs:
     description: 'Engine and version to use, see the syntax in the README. Reads from .ruby-version or .tool-versions if unset.'
     required: false
     default: 'default'
+  rubygems:
+    description: |
+      The version of RubyGems to use. Either 'default', 'latest', or a version number (e.g., 3.3.5).
+      For 'default', no action is taken and the version of RubyGems that comes with Ruby by default is used.
+      For 'latest', `gem update --system` is run to update to the latest RubyGems version.
+      Similarly, if a version number is given, `gem update --system <version>` is run to update to that version of RubyGems.
+      Defaults to 'default'.
   bundler:
     description: |
       The version of Bundler to install. Either 'none', 'latest', 'Gemfile.lock', or a version number (e.g., 1, 2, 2.1.4).

dist/index.js

@@ -3,12 +3,14 @@ const fs = require('fs')
 const path = require('path')
 const core = require('@actions/core')
 const common = require('./common')
+const rubygems = require('./rubygems')
 const bundler = require('./bundler')
 
 const windows = common.windows
 
 const inputDefaults = {
   'ruby-version': 'default',
+  'rubygems': 'default',
   'bundler': 'default',
   'bundler-cache': 'true',
   'working-directory': '.',
@@ -60,6 +62,11 @@ export async function setupRuby(options = {}) {
 
   const rubyPrefix = await installer.install(platform, engine, version)
 
+  if (inputs['rubygems'] !== 'default') {
+    await common.measure('Updating RubyGems', async () =>
+      rubygems.rubygemsUpdate(inputs['rubygems'], rubyPrefix))
+  }
+
   // When setup-ruby is used by other actions, this allows code in them to run
   // before 'bundle install'.  Installed dependencies may require additional
   // libraries & headers, build tools, etc.

index.js

@@ -0,0 +1,11 @@
+const path = require('path')
+const exec = require('@actions/exec')
+
+export async function rubygemsUpdate(rubygemsVersionInput, rubyPrefix) {
+  const gem = path.join(rubyPrefix, 'bin', 'gem')
+  const rubygemsVersion = (rubygemsVersionInput === 'latest') ? [] : [rubygemsVersionInput]
+
+  await exec.exec(gem, ['update', '--system', ...rubygemsVersion])
+
+  return true
+}