Fixup bundler version for rubies with bundler as a default gem

Fixes #117

.github/workflows/test.yml

@@ -15,20 +15,23 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ ubuntu-16.04, ubuntu-18.04, ubuntu-20.04, macos-10.15, windows-2016, windows-2019 ]
+        os: [ ubuntu-16.04, ubuntu-18.04, ubuntu-20.04, macos-10.15, macos-11.0, windows-2016, windows-2019 ]
         # Use various version syntax here for testing
-        ruby: [ 2.1, 2.2, 2.3, 2.4, 2.5, 2.6.6, 2.7, ruby-head, debug, jruby-9.1, jruby, jruby-head, truffleruby, truffleruby-head ]
+        ruby: [ 2.1, 2.2, 2.3, 2.4, 2.5, 2.6.6, 2.7, '3.0', ruby-head, debug, jruby-9.1, jruby, jruby-head, truffleruby, truffleruby-head ]
         include:
         - { os: windows-2016, ruby: mingw }
         - { os: windows-2019, ruby: mingw }
         - { os: windows-2019, ruby: mswin }
         exclude:
+        - { os: windows-2016, ruby: '3.0' }
         - { os: windows-2016, ruby: debug }
         - { os: windows-2016, ruby: truffleruby }
         - { os: windows-2016, ruby: truffleruby-head }
+        - { os: windows-2019, ruby: '3.0' }
         - { os: windows-2019, ruby: debug }
         - { os: windows-2019, ruby: truffleruby }
         - { os: windows-2019, ruby: truffleruby-head }
+        - { os: macos-11.0, ruby: truffleruby }
 
     name: ${{ matrix.os }} ${{ matrix.ruby }}
     runs-on: ${{ matrix.os }}
@@ -100,7 +103,7 @@ jobs:
       run: gem install sassc -N
 
   lint:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
     - uses: actions/checkout@v2
     - run: yarn install

README.md

@@ -16,7 +16,7 @@ This action currently supports these versions of MRI, JRuby and TruffleRuby:
 | ----------- | -------- |
 | Ruby | 2.1.9, 2.2, 2.3.0 - 2.3.8, 2.4.0 - 2.4.10, 2.5.0 - 2.5.8, 2.6.0 - 2.6.6, 2.7.2, head, debug, mingw, mswin |
 | JRuby | 9.1.17.0, 9.2.9.0 - 9.2.13.0, head |
-| TruffleRuby | 19.3.0 - 20.2.0, head |
+| TruffleRuby | 19.3.0 - 20.3.0, head |
 
 `ruby-debug` is the same as `ruby-head` but with assertions enabled (`-DRUBY_DEBUG=1`).  
 On Windows, `mingw` and `mswin` are `ruby-head` builds using the MSYS2/MinGW and the MSVC toolchains respectively.
@@ -39,7 +39,7 @@ The action works for all [GitHub-hosted runners](https://help.github.com/en/acti
 | Operating System | Recommended | Other Supported Versions |
 | ----------- | -------- | -------- |
 | Ubuntu  | `ubuntu-latest`  (= `ubuntu-18.04`) | `ubuntu-20.04`, `ubuntu-16.04` |
-| macOS   | `macos-latest`   (= `macos-10.15`)  | |
+| macOS   | `macos-latest`   (= `macos-10.15`)  | `macos-11.0` |
 | Windows | `windows-latest` (= `windows-2019`) | `windows-2016` |
 
 The prebuilt releases are generated by [ruby-builder](https://github.com/ruby/ruby-builder)
@@ -67,7 +67,6 @@ jobs:
       with:
         ruby-version: 2.6 # Not needed with a .ruby-version file
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically
-    - run: bundle install
     - run: bundle exec rake
 ```
 
@@ -86,14 +85,12 @@ jobs:
         os: [ubuntu, macos]
         ruby: [2.5, 2.6, 2.7, head, debug, jruby, jruby-head, truffleruby, truffleruby-head]
     runs-on: ${{ matrix.os }}-latest
-    continue-on-error: ${{ endsWith(matrix.ruby, 'head') || matrix.ruby == 'debug' }}
     steps:
     - uses: actions/checkout@v2
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically
-    - run: bundle install
     - run: bundle exec rake
 ```
 
@@ -139,38 +136,26 @@ This caching speeds up installing gems significantly and avoids too many request
 It needs a `Gemfile` (or `$BUNDLE_GEMFILE` or `gems.rb`) under the [`working-directory`](#working-directory).  
 If there is a `Gemfile.lock` (or `$BUNDLE_GEMFILE.lock` or `gems.locked`), `bundle config --local deployment true` is used.
 
+To use a `Gemfile` which is not at the root or has a different name, set `BUNDLE_GEMFILE` in the `env` at the job level, so it is set for all steps:
+```yaml
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    env:
+      BUNDLE_GEMFILE: subdir/mygemfile
+    steps:
+    - uses: actions/checkout@v2
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: 2.6
+        bundler-cache: true
+    - run: bundle exec rake
+```
+Of course you can also use a matrix of gemfiles if you need to test multiple gemfiles.
+
 To perform caching, this action will use `bundle config --local path vendor/bundle`.  
 Therefore, the Bundler `path` should not be changed in your workflow for the cache to work (no `bundle config path`).
 
-### Caching `bundle install` manually
-
-You can also cache gems manually,
-but this is not recommended because it is verbose and very difficult to use a correct cache key.
-You can cache the installed gems with these two steps:
-
-```yaml
-    - uses: actions/cache@v2
-      with:
-        path: vendor/bundle
-        key: bundle-use-ruby-${{ matrix.os }}-${{ matrix.ruby }}-${{ hashFiles('**/Gemfile.lock') }}
-        restore-keys: |
-          bundle-use-ruby-${{ matrix.os }}-${{ matrix.ruby }}-
-    - name: bundle install
-      run: |
-        bundle config deployment true
-        bundle config path vendor/bundle
-        bundle install --jobs 4
-```
-
-When using a single OS, replace `${{ matrix.os }}` with the OS.  
-When using a single job with a Ruby version, replace `${{ matrix.ruby }}` with the Ruby version.  
-When using `.ruby-version`, replace `${{ matrix.ruby }}` with `${{ hashFiles('.ruby-version') }}`.  
-When using `.tool-versions`, replace `${{ matrix.ruby }}` with `${{ hashFiles('.tool-versions') }}`.
-
-This uses the [cache action](https://github.com/actions/cache).
-The code above is a more complete version of the [Ruby - Bundler example](https://github.com/actions/cache/blob/master/examples.md#ruby---bundler).
-Make sure to include `use-ruby` in the `key` to avoid conflicting with previous caches.
-
 ## Windows
 
 Note that running CI on Windows can be quite challenging if you are not very familiar with Windows.
@@ -201,6 +186,7 @@ This action might work with [self-hosted runners](https://docs.github.com/en/act
 if the [virtual environment](https://github.com/actions/virtual-environments) is very similar to the ones used by GitHub runners. Notably:
 
 * Make sure to use the same operating system and version.
+* Set the environment variable `ImageOS` to the corresponding value on GitHub-hosted runners (e.g. `ubuntu18`/`macos1015`/`win19`). This is necessary to detect the operating system and version.
 * Make sure to use the same version of libssl.
 * Make sure that the operating system has `libyaml-0` installed
 * The default tool cache directory (`/opt/hostedtoolcache` on Linux, `/Users/runner/hostedtoolcache` on macOS,

common.js

@@ -11,6 +11,14 @@ export const windows = (os.platform() === 'win32')
 // Extract to SSD on Windows, see https://github.com/ruby/setup-ruby/pull/14
 export const drive = (windows ? (process.env['GITHUB_WORKSPACE'] || 'C')[0] : undefined)
 
+export function partition(string, separator) {
+  const i = string.indexOf(separator)
+  if (i === -1) {
+    throw new Error(`No separator ${separator} in string ${string}`)
+  }
+  return [string.slice(0, i), string.slice(i + separator.length, string.length)]
+}
+
 export async function measure(name, block) {
   return await core.group(name, async () => {
     const start = performance.now()
@@ -28,6 +36,10 @@ export function isHeadVersion(rubyVersion) {
   return rubyVersion === 'head' || rubyVersion === 'debug' || rubyVersion === 'mingw' || rubyVersion === 'mswin'
 }
 
+export function isStableVersion(rubyVersion) {
+  return /^\d+(\.\d+)*$/.test(rubyVersion)
+}
+
 export async function hashFile(file) {
   // See https://github.com/actions/runner/blob/master/src/Misc/expressionFunc/hashFiles/src/hashFiles.ts
   const hash = crypto.createHash('sha256')
@@ -36,27 +48,33 @@ export async function hashFile(file) {
   return hash.digest('hex')
 }
 
-export function getVirtualEnvironmentName() {
-  const platform = os.platform()
-  if (platform === 'linux') {
-    return `ubuntu-${findUbuntuVersion()}`
-  } else if (platform === 'darwin') {
-    return 'macos-latest'
-  } else if (platform === 'win32') {
-    return 'windows-latest'
-  } else {
-    throw new Error(`Unknown platform ${platform}`)
+function getImageOS() {
+  const imageOS = process.env['ImageOS']
+  if (!imageOS) {
+    throw new Error('The environment variable ImageOS must be set')
   }
+  return imageOS
 }
 
-function findUbuntuVersion() {
-  const lsb_release = fs.readFileSync('/etc/lsb-release', 'utf8')
-  const match = lsb_release.match(/^DISTRIB_RELEASE=(\d+\.\d+)$/m)
+export function getVirtualEnvironmentName() {
+  const imageOS = getImageOS()
+
+  let match = imageOS.match(/^ubuntu(\d+)/) // e.g. ubuntu18
   if (match) {
-    return match[1]
-  } else {
-    throw new Error('Could not find Ubuntu version')
+    return `ubuntu-${match[1]}.04`
   }
+
+  match = imageOS.match(/^macos(\d{2})(\d+)?/) // e.g. macos1015, macos11
+  if (match) {
+    return `macos-${match[1]}.${match[2] || '0'}`
+  }
+
+  match = imageOS.match(/^win(\d+)/) // e.g. win19
+  if (match) {
+    return `windows-20${match[1]}`
+  }
+
+  throw new Error(`Unknown ImageOS ${imageOS}`)
 }
 
 export function shouldExtractInToolCache(engine, version) {
@@ -85,7 +103,7 @@ export function getToolCacheRubyPrefix(platform, version) {
 export function win2nix(path) {
   if (/^[A-Z]:/i.test(path)) {
     // path starts with drive
-    path = `/${path[0].toLowerCase()}${path.split(':', 2)[1]}`
+    path = `/${path[0].toLowerCase()}${partition(path, ':')[1]}`
   }
   return path.replace(/\\/g, '/').replace(/ /g, '\\ ')
 }

dist/index.js

@@ -27796,7 +27796,7 @@ function addVCVARSEnv() {
   let newSet = cp.execSync(cmd).toString().trim().split(/\r?\n/)
   newSet = newSet.filter(line => line.match(/\S=\S/))
   newSet.forEach(s => {
-    let [k,v] = s.split('=', 2)
+    let [k,v] = common.partition(s, '=')
     newEnv.set(k,v)
   })
 
@@ -32094,8 +32094,10 @@ exports.default = _default;
 __webpack_require__.r(__webpack_exports__);
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "windows", function() { return windows; });
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "drive", function() { return drive; });
+/* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "partition", function() { return partition; });
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "measure", function() { return measure; });
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "isHeadVersion", function() { return isHeadVersion; });
+/* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "isStableVersion", function() { return isStableVersion; });
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "hashFile", function() { return hashFile; });
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "getVirtualEnvironmentName", function() { return getVirtualEnvironmentName; });
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "shouldExtractInToolCache", function() { return shouldExtractInToolCache; });
@@ -32115,6 +32117,14 @@ const windows = (os.platform() === 'win32')
 // Extract to SSD on Windows, see https://github.com/ruby/setup-ruby/pull/14
 const drive = (windows ? (process.env['GITHUB_WORKSPACE'] || 'C')[0] : undefined)
 
+function partition(string, separator) {
+  const i = string.indexOf(separator)
+  if (i === -1) {
+    throw new Error(`No separator ${separator} in string ${string}`)
+  }
+  return [string.slice(0, i), string.slice(i + separator.length, string.length)]
+}
+
 async function measure(name, block) {
   return await core.group(name, async () => {
     const start = performance.now()
@@ -32132,6 +32142,10 @@ function isHeadVersion(rubyVersion) {
   return rubyVersion === 'head' || rubyVersion === 'debug' || rubyVersion === 'mingw' || rubyVersion === 'mswin'
 }
 
+function isStableVersion(rubyVersion) {
+  return /^\d+(\.\d+)*$/.test(rubyVersion)
+}
+
 async function hashFile(file) {
   // See https://github.com/actions/runner/blob/master/src/Misc/expressionFunc/hashFiles/src/hashFiles.ts
   const hash = crypto.createHash('sha256')
@@ -32140,27 +32154,33 @@ async function hashFile(file) {
   return hash.digest('hex')
 }
 
-function getVirtualEnvironmentName() {
-  const platform = os.platform()
-  if (platform === 'linux') {
-    return `ubuntu-${findUbuntuVersion()}`
-  } else if (platform === 'darwin') {
-    return 'macos-latest'
-  } else if (platform === 'win32') {
-    return 'windows-latest'
-  } else {
-    throw new Error(`Unknown platform ${platform}`)
+function getImageOS() {
+  const imageOS = process.env['ImageOS']
+  if (!imageOS) {
+    throw new Error('The environment variable ImageOS must be set')
   }
+  return imageOS
 }
 
-function findUbuntuVersion() {
-  const lsb_release = fs.readFileSync('/etc/lsb-release', 'utf8')
-  const match = lsb_release.match(/^DISTRIB_RELEASE=(\d+\.\d+)$/m)
+function getVirtualEnvironmentName() {
+  const imageOS = getImageOS()
+
+  let match = imageOS.match(/^ubuntu(\d+)/) // e.g. ubuntu18
   if (match) {
-    return match[1]
-  } else {
-    throw new Error('Could not find Ubuntu version')
+    return `ubuntu-${match[1]}.04`
   }
+
+  match = imageOS.match(/^macos(\d{2})(\d+)?/) // e.g. macos1015, macos11
+  if (match) {
+    return `macos-${match[1]}.${match[2] || '0'}`
+  }
+
+  match = imageOS.match(/^win(\d+)/) // e.g. win19
+  if (match) {
+    return `windows-20${match[1]}`
+  }
+
+  throw new Error(`Unknown ImageOS ${imageOS}`)
 }
 
 function shouldExtractInToolCache(engine, version) {
@@ -32189,7 +32209,7 @@ function getToolCacheRubyPrefix(platform, version) {
 function win2nix(path) {
   if (/^[A-Z]:/i.test(path)) {
     // path starts with drive
-    path = `/${path[0].toLowerCase()}${path.split(':', 2)[1]}`
+    path = `/${path[0].toLowerCase()}${partition(path, ':')[1]}`
   }
   return path.replace(/\\/g, '/').replace(/ /g, '\\ ')
 }
@@ -44530,7 +44550,7 @@ function getVersions(platform) {
     ],
     "truffleruby": [
       "19.3.0", "19.3.1",
-      "20.0.0", "20.1.0", "20.2.0",
+      "20.0.0", "20.1.0", "20.2.0", "20.3.0",
       "head"
     ]
   }
@@ -51227,25 +51247,15 @@ async function setupRuby(options = {}) {
   core.setOutput('ruby-prefix', rubyPrefix)
 }
 
+// The returned gemfile is guaranteed to exist, the lockfile might not exist
 function detectGemfiles() {
   const gemfilePath = process.env['BUNDLE_GEMFILE'] || 'Gemfile'
   if (fs.existsSync(gemfilePath)) {
-    const lockPath = `${gemfilePath}.lock`
-    if (fs.existsSync(lockPath)) {
-      return [gemfilePath, lockPath]
-    } else {
-      return [gemfilePath, null]
-    }
+    return [gemfilePath, `${gemfilePath}.lock`]
   }
 
-  const gemsRbPath = "gems.rb"
-  if (fs.existsSync(gemsRbPath)) {
-    const lockPath = "gems.locked"
-    if (fs.existsSync(lockPath)) {
-      return [gemsRbPath, lockPath]
-    } else {
-      return [gemsRbPath, null]
-    }
+  if (fs.existsSync("gems.rb")) {
+    return ["gems.rb", "gems.locked"]
   }
 
   return [null, null]
@@ -51268,7 +51278,7 @@ function parseRubyEngineAndVersion(rubyVersion) {
   } else if (rubyVersion === '.tool-versions') { // Read from .tool-versions
     const toolVersions = fs.readFileSync('.tool-versions', 'utf8').trim()
     const rubyLine = toolVersions.split(/\r?\n/).filter(e => e.match(/^ruby\s/))[0]
-    rubyVersion = rubyLine.split(/\s+/, 2)[1]
+    rubyVersion = rubyLine.match(/^ruby\s+(.+)$/)[1]
     console.log(`Using ${rubyVersion} as input from file .tool-versions`)
   }
 
@@ -51280,7 +51290,7 @@ function parseRubyEngineAndVersion(rubyVersion) {
     engine = rubyVersion
     version = '' // Let the logic in validateRubyEngineAndVersion() find the version
   } else { // engine-X.Y.Z
-    [engine, version] = rubyVersion.split('-', 2)
+    [engine, version] = common.partition(rubyVersion, '-')
   }
 
   return [engine, version]
@@ -51294,7 +51304,13 @@ function validateRubyEngineAndVersion(platform, engineVersions, engine, parsedVe
   let version = parsedVersion
   if (!engineVersions.includes(parsedVersion)) {
     const latestToFirstVersion = engineVersions.slice().reverse()
-    const found = latestToFirstVersion.find(v => !common.isHeadVersion(v) && v.startsWith(parsedVersion))
+    // Try to match stable versions first, so an empty version (engine-only) matches the latest stable version
+    let found = latestToFirstVersion.find(v => common.isStableVersion(v) && v.startsWith(parsedVersion))
+    if (!found) {
+      // Exclude head versions, they must be exact matches
+      found = latestToFirstVersion.find(v => !common.isHeadVersion(v) && v.startsWith(parsedVersion))
+    }
+
     if (found) {
       version = found
     } else {
@@ -51329,7 +51345,7 @@ function envPreInstall() {
 }
 
 function readBundledWithFromGemfileLock(lockFile) {
-  if (lockFile !== null) {
+  if (lockFile !== null && fs.existsSync(lockFile)) {
     const contents = fs.readFileSync(lockFile, 'utf8')
     const lines = contents.split(/\r?\n/)
     const bundledWithLine = lines.findIndex(line => /^BUNDLED WITH$/.test(line.trim()))
@@ -51367,12 +51383,15 @@ async function installBundler(bundlerVersionInput, lockFile, platform, rubyPrefi
     throw new Error(`Cannot parse bundler input: ${bundlerVersion}`)
   }
 
-  if (rubyVersion.match(/^2\.[12]/)) {
+  if (engine === 'ruby' && rubyVersion.match(/^2\.[12]/)) {
     console.log('Bundler 2 requires Ruby 2.3+, using Bundler 1 on Ruby <= 2.2')
     bundlerVersion = '1'
-  } else if (rubyVersion.startsWith('2.3')) {
+  } else if (engine === 'ruby' && rubyVersion.startsWith('2.3')) {
     console.log('Ruby 2.3 has a bug with Bundler 2 (https://github.com/rubygems/rubygems/issues/3570), using Bundler 1 instead on Ruby 2.3')
     bundlerVersion = '1'
+  } else if (engine === 'jruby' && rubyVersion.startsWith('9.1.')) { // JRuby 9.1 targets Ruby 2.3, treat it the same
+    console.log('JRuby 9.1 has a bug with Bundler 2 (https://github.com/ruby/setup-ruby/issues/108), using Bundler 1 instead on JRuby 9.1')
+    bundlerVersion = '1'
   }
 
   if ((engine === 'ruby' || engine === 'truffleruby') && common.isHeadVersion(rubyVersion) && bundlerVersion === '2') {
@@ -51383,6 +51402,8 @@ async function installBundler(bundlerVersionInput, lockFile, platform, rubyPrefi
     const gem = path.join(rubyPrefix, 'bin', 'gem')
     await exec.exec(gem, ['install', 'bundler', '-v', `~> ${bundlerVersion}`, '--no-document'])
   }
+
+  core.exportVariable('BUNDLER_VERSION', bundlerVersion)
 }
 
 async function bundleInstall(gemfile, lockFile, platform, engine, version) {
@@ -51394,24 +51415,22 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
   // config
   const path = 'vendor/bundle'
 
-  if (lockFile !== null) {
-    await exec.exec('bundle', ['config', '--local', 'deployment', 'true'])
-  }
   await exec.exec('bundle', ['config', '--local', 'path', path])
 
+  if (fs.existsSync(lockFile)) {
+    await exec.exec('bundle', ['config', '--local', 'deployment', 'true'])
+  } else {
+    // Generate the lockfile so we can use it to compute the cache key.
+    // This will also automatically pick up the latest gem versions compatible with the Gemfile.
+    await exec.exec('bundle', ['lock'])
+  }
+
   // cache key
   const paths = [path]
-  const baseKey = await computeBaseKey(platform, engine, version, gemfile)
-  let key = baseKey
-  let restoreKeys
-  if (lockFile !== null) {
-    key += `-${lockFile}-${await common.hashFile(lockFile)}`
-    // If only Gemfile.lock changes we can reuse part of the cache (but it will keep old gem versions in the cache)
-    restoreKeys = [`${baseKey}-${lockFile}-`]
-  } else {
-    // Only exact key, to never mix native gems of different platforms or Ruby versions
-    restoreKeys = []
-  }
+  const baseKey = await computeBaseKey(platform, engine, version, lockFile)
+  const key = `${baseKey}-${await common.hashFile(lockFile)}`
+  // If only Gemfile.lock changes we can reuse part of the cache, and clean old gem versions below
+  const restoreKeys = [`${baseKey}-`]
   console.log(`Cache key: ${key}`)
 
   // restore cache & install
@@ -51430,14 +51449,14 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
     console.log(`Found cache for key: ${cachedKey}`)
   }
 
-  let alreadyInstalled = false
-  if (cachedKey === key) {
-    const exitCode = await exec.exec('bundle', ['check'], { ignoreReturnCode: true })
-    alreadyInstalled = (exitCode === 0)
-  }
+  // Always run 'bundle install' to list the gems
+  await exec.exec('bundle', ['install', '--jobs', '4'])
 
-  if (!alreadyInstalled) {
-    await exec.exec('bundle', ['install', '--jobs', '4'])
+  // @actions/cache only allows to save for non-existing keys
+  if (cachedKey !== key) {
+    if (cachedKey) { // existing cache but Gemfile.lock differs, clean old gems
+      await exec.exec('bundle', ['clean'])
+    }
 
     // Error handling from https://github.com/actions/cache/blob/master/src/save.ts
     console.log('Saving cache')
@@ -51457,8 +51476,9 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
   return true
 }
 
-async function computeBaseKey(platform, engine, version, gemfile) {
-  let baseKey = `setup-ruby-toolcache-bundle-install-${platform}-${engine}-${version}-${gemfile}`
+async function computeBaseKey(platform, engine, version, lockFile) {
+  let key = `setup-ruby-bundler-cache-v2-${platform}-${engine}-${version}`
+
   if (engine !== 'jruby' && common.isHeadVersion(version)) {
     let revision = '';
     await exec.exec('ruby', ['-e', 'print RUBY_REVISION'], {
@@ -51469,9 +51489,11 @@ async function computeBaseKey(platform, engine, version, gemfile) {
         }
       }
     });
-    baseKey += `-revision-${revision}`
+    key += `-revision-${revision}`
   }
-  return baseKey
+
+  key += `-${lockFile}`
+  return key
 }
 
 if (__filename.endsWith('index.js')) { run() }
@@ -52945,10 +52967,17 @@ async function downloadAndExtract(platform, engine, version) {
 }
 
 function getDownloadURL(platform, engine, version) {
+  let builderPlatform = platform
+  if (platform.startsWith('windows-')) {
+    builderPlatform = 'windows-latest'
+  } else if (platform.startsWith('macos-')) {
+    builderPlatform = 'macos-latest'
+  }
+
   if (common.isHeadVersion(version)) {
-    return getLatestHeadBuildURL(platform, engine, version)
+    return getLatestHeadBuildURL(builderPlatform, engine, version)
   } else {
-    return `${releasesURL}/download/${builderReleaseTag}/${engine}-${version}-${platform}.tar.gz`
+    return `${releasesURL}/download/${builderReleaseTag}/${engine}-${version}-${builderPlatform}.tar.gz`
   }
 }
 

index.js

@@ -75,25 +75,15 @@ export async function setupRuby(options = {}) {
   core.setOutput('ruby-prefix', rubyPrefix)
 }
 
+// The returned gemfile is guaranteed to exist, the lockfile might not exist
 function detectGemfiles() {
   const gemfilePath = process.env['BUNDLE_GEMFILE'] || 'Gemfile'
   if (fs.existsSync(gemfilePath)) {
-    const lockPath = `${gemfilePath}.lock`
-    if (fs.existsSync(lockPath)) {
-      return [gemfilePath, lockPath]
-    } else {
-      return [gemfilePath, null]
-    }
+    return [gemfilePath, `${gemfilePath}.lock`]
   }
 
-  const gemsRbPath = "gems.rb"
-  if (fs.existsSync(gemsRbPath)) {
-    const lockPath = "gems.locked"
-    if (fs.existsSync(lockPath)) {
-      return [gemsRbPath, lockPath]
-    } else {
-      return [gemsRbPath, null]
-    }
+  if (fs.existsSync("gems.rb")) {
+    return ["gems.rb", "gems.locked"]
   }
 
   return [null, null]
@@ -116,7 +106,7 @@ function parseRubyEngineAndVersion(rubyVersion) {
   } else if (rubyVersion === '.tool-versions') { // Read from .tool-versions
     const toolVersions = fs.readFileSync('.tool-versions', 'utf8').trim()
     const rubyLine = toolVersions.split(/\r?\n/).filter(e => e.match(/^ruby\s/))[0]
-    rubyVersion = rubyLine.split(/\s+/, 2)[1]
+    rubyVersion = rubyLine.match(/^ruby\s+(.+)$/)[1]
     console.log(`Using ${rubyVersion} as input from file .tool-versions`)
   }
 
@@ -128,7 +118,7 @@ function parseRubyEngineAndVersion(rubyVersion) {
     engine = rubyVersion
     version = '' // Let the logic in validateRubyEngineAndVersion() find the version
   } else { // engine-X.Y.Z
-    [engine, version] = rubyVersion.split('-', 2)
+    [engine, version] = common.partition(rubyVersion, '-')
   }
 
   return [engine, version]
@@ -142,7 +132,13 @@ function validateRubyEngineAndVersion(platform, engineVersions, engine, parsedVe
   let version = parsedVersion
   if (!engineVersions.includes(parsedVersion)) {
     const latestToFirstVersion = engineVersions.slice().reverse()
-    const found = latestToFirstVersion.find(v => !common.isHeadVersion(v) && v.startsWith(parsedVersion))
+    // Try to match stable versions first, so an empty version (engine-only) matches the latest stable version
+    let found = latestToFirstVersion.find(v => common.isStableVersion(v) && v.startsWith(parsedVersion))
+    if (!found) {
+      // Exclude head versions, they must be exact matches
+      found = latestToFirstVersion.find(v => !common.isHeadVersion(v) && v.startsWith(parsedVersion))
+    }
+
     if (found) {
       version = found
     } else {
@@ -177,7 +173,7 @@ function envPreInstall() {
 }
 
 function readBundledWithFromGemfileLock(lockFile) {
-  if (lockFile !== null) {
+  if (lockFile !== null && fs.existsSync(lockFile)) {
     const contents = fs.readFileSync(lockFile, 'utf8')
     const lines = contents.split(/\r?\n/)
     const bundledWithLine = lines.findIndex(line => /^BUNDLED WITH$/.test(line.trim()))
@@ -215,12 +211,15 @@ async function installBundler(bundlerVersionInput, lockFile, platform, rubyPrefi
     throw new Error(`Cannot parse bundler input: ${bundlerVersion}`)
   }
 
-  if (rubyVersion.match(/^2\.[12]/)) {
+  if (engine === 'ruby' && rubyVersion.match(/^2\.[12]/)) {
     console.log('Bundler 2 requires Ruby 2.3+, using Bundler 1 on Ruby <= 2.2')
     bundlerVersion = '1'
-  } else if (rubyVersion.startsWith('2.3')) {
+  } else if (engine === 'ruby' && rubyVersion.startsWith('2.3')) {
     console.log('Ruby 2.3 has a bug with Bundler 2 (https://github.com/rubygems/rubygems/issues/3570), using Bundler 1 instead on Ruby 2.3')
     bundlerVersion = '1'
+  } else if (engine === 'jruby' && rubyVersion.startsWith('9.1.')) { // JRuby 9.1 targets Ruby 2.3, treat it the same
+    console.log('JRuby 9.1 has a bug with Bundler 2 (https://github.com/ruby/setup-ruby/issues/108), using Bundler 1 instead on JRuby 9.1')
+    bundlerVersion = '1'
   }
 
   if ((engine === 'ruby' || engine === 'truffleruby') && common.isHeadVersion(rubyVersion) && bundlerVersion === '2') {
@@ -231,6 +230,8 @@ async function installBundler(bundlerVersionInput, lockFile, platform, rubyPrefi
     const gem = path.join(rubyPrefix, 'bin', 'gem')
     await exec.exec(gem, ['install', 'bundler', '-v', `~> ${bundlerVersion}`, '--no-document'])
   }
+
+  core.exportVariable('BUNDLER_VERSION', bundlerVersion)
 }
 
 async function bundleInstall(gemfile, lockFile, platform, engine, version) {
@@ -242,24 +243,22 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
   // config
   const path = 'vendor/bundle'
 
-  if (lockFile !== null) {
-    await exec.exec('bundle', ['config', '--local', 'deployment', 'true'])
-  }
   await exec.exec('bundle', ['config', '--local', 'path', path])
 
+  if (fs.existsSync(lockFile)) {
+    await exec.exec('bundle', ['config', '--local', 'deployment', 'true'])
+  } else {
+    // Generate the lockfile so we can use it to compute the cache key.
+    // This will also automatically pick up the latest gem versions compatible with the Gemfile.
+    await exec.exec('bundle', ['lock'])
+  }
+
   // cache key
   const paths = [path]
-  const baseKey = await computeBaseKey(platform, engine, version, gemfile)
-  let key = baseKey
-  let restoreKeys
-  if (lockFile !== null) {
-    key += `-${lockFile}-${await common.hashFile(lockFile)}`
-    // If only Gemfile.lock changes we can reuse part of the cache (but it will keep old gem versions in the cache)
-    restoreKeys = [`${baseKey}-${lockFile}-`]
-  } else {
-    // Only exact key, to never mix native gems of different platforms or Ruby versions
-    restoreKeys = []
-  }
+  const baseKey = await computeBaseKey(platform, engine, version, lockFile)
+  const key = `${baseKey}-${await common.hashFile(lockFile)}`
+  // If only Gemfile.lock changes we can reuse part of the cache, and clean old gem versions below
+  const restoreKeys = [`${baseKey}-`]
   console.log(`Cache key: ${key}`)
 
   // restore cache & install
@@ -278,14 +277,14 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
     console.log(`Found cache for key: ${cachedKey}`)
   }
 
-  let alreadyInstalled = false
-  if (cachedKey === key) {
-    const exitCode = await exec.exec('bundle', ['check'], { ignoreReturnCode: true })
-    alreadyInstalled = (exitCode === 0)
-  }
+  // Always run 'bundle install' to list the gems
+  await exec.exec('bundle', ['install', '--jobs', '4'])
 
-  if (!alreadyInstalled) {
-    await exec.exec('bundle', ['install', '--jobs', '4'])
+  // @actions/cache only allows to save for non-existing keys
+  if (cachedKey !== key) {
+    if (cachedKey) { // existing cache but Gemfile.lock differs, clean old gems
+      await exec.exec('bundle', ['clean'])
+    }
 
     // Error handling from https://github.com/actions/cache/blob/master/src/save.ts
     console.log('Saving cache')
@@ -305,8 +304,9 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
   return true
 }
 
-async function computeBaseKey(platform, engine, version, gemfile) {
-  let baseKey = `setup-ruby-toolcache-bundle-install-${platform}-${engine}-${version}-${gemfile}`
+async function computeBaseKey(platform, engine, version, lockFile) {
+  let key = `setup-ruby-bundler-cache-v2-${platform}-${engine}-${version}`
+
   if (engine !== 'jruby' && common.isHeadVersion(version)) {
     let revision = '';
     await exec.exec('ruby', ['-e', 'print RUBY_REVISION'], {
@@ -317,9 +317,11 @@ async function computeBaseKey(platform, engine, version, gemfile) {
         }
       }
     });
-    baseKey += `-revision-${revision}`
+    key += `-revision-${revision}`
   }
-  return baseKey
+
+  key += `-${lockFile}`
+  return key
 }
 
 if (__filename.endsWith('index.js')) { run() }

ruby-builder-versions.js

@@ -18,7 +18,7 @@ export function getVersions(platform) {
     ],
     "truffleruby": [
       "19.3.0", "19.3.1",
-      "20.0.0", "20.1.0", "20.2.0",
+      "20.0.0", "20.1.0", "20.2.0", "20.3.0",
       "head"
     ]
   }

ruby-builder.js

@@ -57,10 +57,17 @@ async function downloadAndExtract(platform, engine, version) {
 }
 
 function getDownloadURL(platform, engine, version) {
+  let builderPlatform = platform
+  if (platform.startsWith('windows-')) {
+    builderPlatform = 'windows-latest'
+  } else if (platform.startsWith('macos-')) {
+    builderPlatform = 'macos-latest'
+  }
+
   if (common.isHeadVersion(version)) {
-    return getLatestHeadBuildURL(platform, engine, version)
+    return getLatestHeadBuildURL(builderPlatform, engine, version)
   } else {
-    return `${releasesURL}/download/${builderReleaseTag}/${engine}-${version}-${platform}.tar.gz`
+    return `${releasesURL}/download/${builderReleaseTag}/${engine}-${version}-${builderPlatform}.tar.gz`
   }
 }
 

windows.js

@@ -120,7 +120,7 @@ export function addVCVARSEnv() {
   let newSet = cp.execSync(cmd).toString().trim().split(/\r?\n/)
   newSet = newSet.filter(line => line.match(/\S=\S/))
   newSet.forEach(s => {
-    let [k,v] = s.split('=', 2)
+    let [k,v] = common.partition(s, '=')
     newEnv.set(k,v)
   })