Also include the version in the platform for macos and windows

* Guess the platform based on $ImageOS.

common.js

@@ -36,27 +36,33 @@ export async function hashFile(file) {
   return hash.digest('hex')
 }
 
-export function getVirtualEnvironmentName() {
+function getImageOS() {
-  const platform = os.platform()
+  const imageOS = process.env['ImageOS']
-  if (platform === 'linux') {
+  if (!imageOS) {
-    return `ubuntu-${findUbuntuVersion()}`
+    throw new Error('The environment variable ImageOS must be set')
-  } else if (platform === 'darwin') {
-    return 'macos-latest'
-  } else if (platform === 'win32') {
-    return 'windows-latest'
-  } else {
-    throw new Error(`Unknown platform ${platform}`)
   }
+  return imageOS
 }
 
-function findUbuntuVersion() {
+export function getVirtualEnvironmentName() {
-  const lsb_release = fs.readFileSync('/etc/lsb-release', 'utf8')
+  const imageOS = getImageOS()
-  const match = lsb_release.match(/^DISTRIB_RELEASE=(\d+\.\d+)$/m)
+
+  let match = imageOS.match(/^ubuntu(\d+)/) // e.g. ubuntu18
   if (match) {
-    return match[1]
+    return `ubuntu-${match[1]}.04`
-  } else {
-    throw new Error('Could not find Ubuntu version')
   }
+
+  match = imageOS.match(/^macos(\d{2})(\d+)/) // e.g. macos1015
+  if (match) {
+    return `macos-${match[1]}.${match[2]}`
+  }
+
+  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) {

dist/index.js

@@ -32140,27 +32140,33 @@ async function hashFile(file) {
   return hash.digest('hex')
 }
 
-function getVirtualEnvironmentName() {
+function getImageOS() {
-  const platform = os.platform()
+  const imageOS = process.env['ImageOS']
-  if (platform === 'linux') {
+  if (!imageOS) {
-    return `ubuntu-${findUbuntuVersion()}`
+    throw new Error('The environment variable ImageOS must be set')
-  } else if (platform === 'darwin') {
-    return 'macos-latest'
-  } else if (platform === 'win32') {
-    return 'windows-latest'
-  } else {
-    throw new Error(`Unknown platform ${platform}`)
   }
+  return imageOS
 }
 
-function findUbuntuVersion() {
+function getVirtualEnvironmentName() {
-  const lsb_release = fs.readFileSync('/etc/lsb-release', 'utf8')
+  const imageOS = getImageOS()
-  const match = lsb_release.match(/^DISTRIB_RELEASE=(\d+\.\d+)$/m)
+
+  let match = imageOS.match(/^ubuntu(\d+)/) // e.g. ubuntu18
   if (match) {
-    return match[1]
+    return `ubuntu-${match[1]}.04`
-  } else {
-    throw new Error('Could not find Ubuntu version')
   }
+
+  match = imageOS.match(/^macos(\d{2})(\d+)/) // e.g. macos1015
+  if (match) {
+    return `macos-${match[1]}.${match[2]}`
+  }
+
+  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) {
@@ -51227,25 +51233,15 @@ 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 = `${gemfilePath}.lock`
+    return [gemfilePath, `${gemfilePath}.lock`]
-    if (fs.existsSync(lockPath)) {
-      return [gemfilePath, lockPath]
-    } else {
-      return [gemfilePath, null]
-    }
   }
 
-  const gemsRbPath = "gems.rb"
+  if (fs.existsSync("gems.rb")) {
-  if (fs.existsSync(gemsRbPath)) {
+    return ["gems.rb", "gems.locked"]
-    const lockPath = "gems.locked"
-    if (fs.existsSync(lockPath)) {
-      return [gemsRbPath, lockPath]
-    } else {
-      return [gemsRbPath, null]
-    }
   }
 
   return [null, null]
@@ -51329,7 +51325,7 @@ 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 +51363,15 @@ 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') {
@@ -51394,24 +51393,22 @@ 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)
+  const baseKey = await computeBaseKey(platform, engine, version, lockFile)
-  let key = baseKey
+  const key = `${baseKey}-${await common.hashFile(lockFile)}`
-  let restoreKeys
+  // If only Gemfile.lock changes we can reuse part of the cache (but it will keep old gem versions in the cache)
-  if (lockFile !== null) {
+  const restoreKeys = [`${baseKey}-`]
-    key += `-${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 = []
-  }
   console.log(`Cache key: ${key}`)
 
   // restore cache & install
@@ -51430,15 +51427,11 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
     console.log(`Found cache for key: ${cachedKey}`)
   }
 
-  let alreadyInstalled = false
+  // Always run 'bundle install' to list the gems
-  if (cachedKey === key) {
+  await exec.exec('bundle', ['install', '--jobs', '4'])
-    const exitCode = await exec.exec('bundle', ['check'], { ignoreReturnCode: true })
-    alreadyInstalled = (exitCode === 0)
-  }
-
-  if (!alreadyInstalled) {
-    await exec.exec('bundle', ['install', '--jobs', '4'])
 
+  // @actions/cache only allows to save for non-existing keys
+  if (cachedKey !== key) {
     // Error handling from https://github.com/actions/cache/blob/master/src/save.ts
     console.log('Saving cache')
     try {
@@ -51457,8 +51450,9 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
   return true
 }
 
-async function computeBaseKey(platform, engine, version, gemfile) {
+async function computeBaseKey(platform, engine, version, lockFile) {
-  let baseKey = `setup-ruby-toolcache-bundle-install-${platform}-${engine}-${version}-${gemfile}`
+  let key = `setup-ruby-bundler-cache-v2-${platform}-${engine}-${version}`
+
   if (engine !== 'jruby' && common.isHeadVersion(version)) {
     let revision = '';
     await exec.exec('ruby', ['-e', 'print RUBY_REVISION'], {
@@ -51469,9 +51463,11 @@ async function computeBaseKey(platform, engine, version, gemfile) {
         }
       }
     });
-    baseKey += `-revision-${revision}`
+    key += `-revision-${revision}`
   }
-  return baseKey
+
+  key += `-${lockFile}`
+  return key
 }
 
 if (__filename.endsWith('index.js')) { run() }
@@ -52945,10 +52941,17 @@ 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 = `${gemfilePath}.lock`
+    return [gemfilePath, `${gemfilePath}.lock`]
-    if (fs.existsSync(lockPath)) {
-      return [gemfilePath, lockPath]
-    } else {
-      return [gemfilePath, null]
-    }
   }
 
-  const gemsRbPath = "gems.rb"
+  if (fs.existsSync("gems.rb")) {
-  if (fs.existsSync(gemsRbPath)) {
+    return ["gems.rb", "gems.locked"]
-    const lockPath = "gems.locked"
-    if (fs.existsSync(lockPath)) {
-      return [gemsRbPath, lockPath]
-    } else {
-      return [gemsRbPath, null]
-    }
   }
 
   return [null, null]
@@ -177,7 +167,7 @@ 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 +205,15 @@ 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') {
@@ -242,24 +235,22 @@ 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)
+  const baseKey = await computeBaseKey(platform, engine, version, lockFile)
-  let key = baseKey
+  const key = `${baseKey}-${await common.hashFile(lockFile)}`
-  let restoreKeys
+  // If only Gemfile.lock changes we can reuse part of the cache (but it will keep old gem versions in the cache)
-  if (lockFile !== null) {
+  const restoreKeys = [`${baseKey}-`]
-    key += `-${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 = []
-  }
   console.log(`Cache key: ${key}`)
 
   // restore cache & install
@@ -278,15 +269,11 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
     console.log(`Found cache for key: ${cachedKey}`)
   }
 
-  let alreadyInstalled = false
+  // Always run 'bundle install' to list the gems
-  if (cachedKey === key) {
+  await exec.exec('bundle', ['install', '--jobs', '4'])
-    const exitCode = await exec.exec('bundle', ['check'], { ignoreReturnCode: true })
-    alreadyInstalled = (exitCode === 0)
-  }
-
-  if (!alreadyInstalled) {
-    await exec.exec('bundle', ['install', '--jobs', '4'])
 
+  // @actions/cache only allows to save for non-existing keys
+  if (cachedKey !== key) {
     // Error handling from https://github.com/actions/cache/blob/master/src/save.ts
     console.log('Saving cache')
     try {
@@ -305,8 +292,9 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
   return true
 }
 
-async function computeBaseKey(platform, engine, version, gemfile) {
+async function computeBaseKey(platform, engine, version, lockFile) {
-  let baseKey = `setup-ruby-toolcache-bundle-install-${platform}-${engine}-${version}-${gemfile}`
+  let key = `setup-ruby-bundler-cache-v2-${platform}-${engine}-${version}`
+
   if (engine !== 'jruby' && common.isHeadVersion(version)) {
     let revision = '';
     await exec.exec('ruby', ['-e', 'print RUBY_REVISION'], {
@@ -317,9 +305,11 @@ async function computeBaseKey(platform, engine, version, gemfile) {
         }
       }
     });
-    baseKey += `-revision-${revision}`
+    key += `-revision-${revision}`
   }
-  return baseKey
+
+  key += `-${lockFile}`
+  return key
 }
 
 if (__filename.endsWith('index.js')) { run() }

ruby-builder.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`
   }
 }