Fix automatic bundler installation on JRuby 9.2

bundler.js

@@ -107,7 +107,6 @@ export async function installBundler(bundlerVersionInput, rubygemsInputSet, lock
   }
 
   // Use Bundler 1 when we know Bundler 2 does not work
-  // Use Bundler 2.3 when we use Ruby 2.3.2-2.5
   if (bundlerVersion.startsWith('2')) {
     if (engine === 'ruby' && floatVersion <= 2.2) {
       console.log('Bundler 2 requires Ruby 2.3+, using Bundler 1 on Ruby <= 2.2')
@@ -115,15 +114,25 @@ export async function installBundler(bundlerVersionInput, rubygemsInputSet, lock
     } else if (engine === 'ruby' && /^2\.3\.[01]/.test(rubyVersion)) {
       console.log('Ruby 2.3.0 and 2.3.1 have shipped with an old rubygems that only works with Bundler 1')
       bundlerVersion = '1'
-    } else if (engine === 'ruby' && floatVersion <= 2.5) {
-      console.log('Ruby 2.3.2-2.5 only works with Bundler 2.3')
-      bundlerVersion = '2.3'
     } 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'
     }
   }
 
+  const targetRubyVersion = common.targetRubyVersion(engine, rubyVersion)
+  // Use Bundler 2.3 when we use Ruby 2.3.2 - 2.5
+  // Use Bundler 2.4 when we use Ruby 2.6-2.7
+  if (bundlerVersion == '2') {
+    if (targetRubyVersion <= 2.5) { // < 2.3.2 already handled above
+      console.log('Ruby 2.3.2 - 2.5 only works with Bundler 2.3')
+      bundlerVersion = '2.3'
+    } else if (targetRubyVersion <= 2.7) {
+      console.log('Ruby 2.6-2.7 only works with Bundler 2.4')
+      bundlerVersion = '2.4'
+    }
+  }
+
   const gem = path.join(rubyPrefix, 'bin', 'gem')
   // Workaround for https://github.com/rubygems/rubygems/issues/5245
   // and for https://github.com/oracle/truffleruby/issues/2780

common.js

@@ -95,6 +95,23 @@ export function isBundler2dot2Default(engine, rubyVersion) {
   }
 }
 
+export function targetRubyVersion(engine, rubyVersion) {
+  const version = floatVersion(rubyVersion)
+  if (engine === 'ruby') {
+    return version
+  } else if (engine === 'jruby') {
+    if (version === 9.1) {
+      return 2.3
+    } else if (version === 9.2) {
+      return 2.5
+    } else if (version === 9.3) {
+      return 2.6
+    }
+  }
+
+  return 9.9 // unknown, assume recent
+}
+
 export function floatVersion(rubyVersion) {
   const match = rubyVersion.match(/^\d+\.\d+/)
   if (match) {

dist/index.js

@@ -122,7 +122,6 @@ async function installBundler(bundlerVersionInput, rubygemsInputSet, lockFile, p
   }
 
   // Use Bundler 1 when we know Bundler 2 does not work
-  // Use Bundler 2.3 when we use Ruby 2.3.2-2.5
   if (bundlerVersion.startsWith('2')) {
     if (engine === 'ruby' && floatVersion <= 2.2) {
       console.log('Bundler 2 requires Ruby 2.3+, using Bundler 1 on Ruby <= 2.2')
@@ -130,15 +129,25 @@ async function installBundler(bundlerVersionInput, rubygemsInputSet, lockFile, p
     } else if (engine === 'ruby' && /^2\.3\.[01]/.test(rubyVersion)) {
       console.log('Ruby 2.3.0 and 2.3.1 have shipped with an old rubygems that only works with Bundler 1')
       bundlerVersion = '1'
-    } else if (engine === 'ruby' && floatVersion <= 2.5) {
-      console.log('Ruby 2.3.2-2.5 only works with Bundler 2.3')
-      bundlerVersion = '2.3'
     } 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'
     }
   }
 
+  const targetRubyVersion = common.targetRubyVersion(engine, rubyVersion)
+  // Use Bundler 2.3 when we use Ruby 2.3.2 - 2.5
+  // Use Bundler 2.4 when we use Ruby 2.6-2.7
+  if (bundlerVersion == '2') {
+    if (targetRubyVersion <= 2.5) { // < 2.3.2 already handled above
+      console.log('Ruby 2.3.2 - 2.5 only works with Bundler 2.3')
+      bundlerVersion = '2.3'
+    } else if (targetRubyVersion <= 2.7) {
+      console.log('Ruby 2.6-2.7 only works with Bundler 2.4')
+      bundlerVersion = '2.4'
+    }
+  }
+
   const gem = path.join(rubyPrefix, 'bin', 'gem')
   // Workaround for https://github.com/rubygems/rubygems/issues/5245
   // and for https://github.com/oracle/truffleruby/issues/2780
@@ -277,6 +286,7 @@ __nccwpck_require__.r(__webpack_exports__);
 /* harmony export */   "isBundler1Default": () => (/* binding */ isBundler1Default),
 /* harmony export */   "isBundler2Default": () => (/* binding */ isBundler2Default),
 /* harmony export */   "isBundler2dot2Default": () => (/* binding */ isBundler2dot2Default),
+/* harmony export */   "targetRubyVersion": () => (/* binding */ targetRubyVersion),
 /* harmony export */   "floatVersion": () => (/* binding */ floatVersion),
 /* harmony export */   "hashFile": () => (/* binding */ hashFile),
 /* harmony export */   "supportedPlatforms": () => (/* binding */ supportedPlatforms),
@@ -384,6 +394,23 @@ function isBundler2dot2Default(engine, rubyVersion) {
   }
 }
 
+function targetRubyVersion(engine, rubyVersion) {
+  const version = floatVersion(rubyVersion)
+  if (engine === 'ruby') {
+    return version
+  } else if (engine === 'jruby') {
+    if (version === 9.1) {
+      return 2.3
+    } else if (version === 9.2) {
+      return 2.5
+    } else if (version === 9.3) {
+      return 2.6
+    }
+  }
+
+  return 9.9 // unknown, assume recent
+}
+
 function floatVersion(rubyVersion) {
   const match = rubyVersion.match(/^\d+\.\d+/)
   if (match) {