fix(ruby): support multi-part version constraints in Gemfile

core/__snapshots__/TestGenerateBuildPlanForExamples_ruby-single-version_1.snap.json

@@ -0,0 +1,171 @@
+{
+ "caches": {
+  "apt": {
+   "directory": "/var/cache/apt",
+   "type": "locked"
+  },
+  "apt-lists": {
+   "directory": "/var/lib/apt/lists",
+   "type": "locked"
+  }
+ },
+ "deploy": {
+  "base": {
+   "step": "packages:apt:runtime"
+  },
+  "inputs": [
+   {
+    "include": [
+     "/mise/shims",
+     "/mise/installs",
+     "/usr/local/bin/mise",
+     "/etc/mise/config.toml",
+     "/root/.local/state/mise"
+    ],
+    "step": "packages:mise"
+   },
+   {
+    "include": [
+     "/usr/local/bundle"
+    ],
+    "step": "install"
+   },
+   {
+    "include": [
+     "/app"
+    ],
+    "step": "build"
+   }
+  ],
+  "startCommand": "bundle exec rackup config.ru -p ${PORT:-3000}",
+  "variables": {
+   "BUNDLE_GEMFILE": "/app/Gemfile",
+   "GEM_HOME": "/usr/local/bundle",
+   "GEM_PATH": "/usr/local/bundle",
+   "MALLOC_ARENA_MAX": "2"
+  }
+ },
+ "steps": [
+  {
+   "caches": [
+    "apt",
+    "apt-lists"
+   ],
+   "commands": [
+    {
+     "cmd": "sh -c 'apt-get update \u0026\u0026 apt-get install -y cargo libyaml-dev rustc'",
+     "customName": "install apt packages: cargo libyaml-dev rustc"
+    }
+   ],
+   "inputs": [
+    {
+     "image": "ghcr.io/railwayapp/railpack-builder:latest"
+    }
+   ],
+   "name": "packages:apt:build"
+  },
+  {
+   "assets": {
+    "mise.toml": "[mise.toml]"
+   },
+   "commands": [
+    {
+     "path": "/mise/shims"
+    },
+    {
+     "customName": "create mise config",
+     "name": "mise.toml",
+     "path": "/etc/mise/config.toml"
+    },
+    {
+     "cmd": "sh -c 'mise trust -a \u0026\u0026 mise install'",
+     "customName": "install mise packages: ruby"
+    }
+   ],
+   "inputs": [
+    {
+     "step": "packages:apt:build"
+    }
+   ],
+   "name": "packages:mise",
+   "variables": {
+    "MISE_CACHE_DIR": "/mise/cache",
+    "MISE_CONFIG_DIR": "/mise",
+    "MISE_DATA_DIR": "/mise",
+    "MISE_INSTALLS_DIR": "/mise/installs",
+    "MISE_SHIMS_DIR": "/mise/shims"
+   }
+  },
+  {
+   "commands": [
+    {
+     "cmd": "gem install -N bundler:2.4.22"
+    },
+    {
+     "dest": "Gemfile",
+     "src": "Gemfile"
+    },
+    {
+     "dest": "Gemfile.lock",
+     "src": "Gemfile.lock"
+    },
+    {
+     "cmd": "bundle install"
+    },
+    {
+     "path": "/usr/local/bundle"
+    }
+   ],
+   "inputs": [
+    {
+     "step": "packages:mise"
+    }
+   ],
+   "name": "install",
+   "variables": {
+    "BUNDLE_GEMFILE": "/app/Gemfile",
+    "GEM_HOME": "/usr/local/bundle",
+    "GEM_PATH": "/usr/local/bundle",
+    "MALLOC_ARENA_MAX": "2"
+   }
+  },
+  {
+   "commands": [
+    {
+     "dest": ".",
+     "src": "."
+    }
+   ],
+   "inputs": [
+    {
+     "step": "install"
+    }
+   ],
+   "name": "build",
+   "variables": {
+    "BUNDLE_GEMFILE": "/app/Gemfile",
+    "GEM_HOME": "/usr/local/bundle",
+    "GEM_PATH": "/usr/local/bundle",
+    "MALLOC_ARENA_MAX": "2"
+   }
+  },
+  {
+   "caches": [
+    "apt",
+    "apt-lists"
+   ],
+   "commands": [
+    {
+     "cmd": "sh -c 'apt-get update \u0026\u0026 apt-get install -y libyaml-dev'",
+     "customName": "install apt packages: libyaml-dev"
+    }
+   ],
+   "inputs": [
+    {
+     "image": "ghcr.io/railwayapp/railpack-runtime:latest"
+    }
+   ],
+   "name": "packages:apt:runtime"
+  }
+ ]
+}

core/providers/ruby/ruby.go

@@ -245,8 +245,9 @@ func (p *RubyProvider) InstallMisePackages(ctx *generate.GenerateContext, miseSt
 		miseStep.Version(ruby, utils.ExtractSemverVersion(string(versionFile)), ".ruby-version")
 	}
 
-	if gemfileVersion := parseVersionFromGemfile(ctx); gemfileVersion != "" {
-		miseStep.Version(ruby, gemfileVersion, "Gemfile")
+	if constraint := extractRubyConstraintFromGemfile(ctx); constraint != "" {
+		miseStep.Resolver.SetVersionAvailable(ruby, isStableRubyVersion)
+		miseStep.Version(ruby, constraint, "Gemfile")
 	}
 
 	miseStep.AddSupportingAptPackage("libyaml-dev")
@@ -261,6 +262,11 @@ func (p *RubyProvider) InstallMisePackages(ctx *generate.GenerateContext, miseSt
 	}
 }
 
+func isStableRubyVersion(version string) bool {
+	return !(strings.Contains(version, "-dev") || strings.Contains(version, "-preview") ||
+		strings.Contains(version, "-rc") || strings.Contains(version, "dev"))
+}
+
 func (p *RubyProvider) getRubyVersion(ctx *generate.GenerateContext) string {
 	miseStepBuilder := ctx.GetMiseStepBuilder()
 	pkg := miseStepBuilder.Resolver.Get("ruby")
@@ -320,35 +326,9 @@ func (p *RubyProvider) addMetadata(ctx *generate.GenerateContext) {
 }
 
 var (
-	gemfileVersionRegex     = regexp.MustCompile(`ruby (?:'|")(.*)(?:'|")[^>]"`)
-	gemfileLockVersionRegex = regexp.MustCompile(`ruby ((?:0|[1-9]\d*)\.(?:0|[1-9]\d*)\.(?:0|[1-9]\d*))[^>]`)
+	gemfileVersionRegex = regexp.MustCompile(`ruby\s+(?:'|")([^'"]+)(?:'|")`)
 )
 
-func parseVersionFromGemfile(ctx *generate.GenerateContext) string {
-	gemfile, err := ctx.App.ReadFile("Gemfile")
-	if err != nil {
-		return ""
-	}
-
-	matches := gemfileVersionRegex.FindStringSubmatch(string(gemfile))
-
-	if len(matches) > 2 {
-		return matches[2]
-	}
-
-	gemfileLock, err := ctx.App.ReadFile("Gemfile.lock")
-	if err != nil {
-		return ""
-	}
-
-	matches = gemfileLockVersionRegex.FindStringSubmatch(string(gemfileLock))
-	if len(matches) > 1 {
-		return matches[1]
-	}
-
-	return ""
-}
-
 func parseBundlerVersionFromGemfile(ctx *generate.GenerateContext) string {
 	gemfileLock, err := ctx.App.ReadFile("Gemfile.lock")
 	if err != nil {
@@ -393,3 +373,15 @@ func parseLocalPathsFromGemfile(ctx *generate.GenerateContext) []string {
 
 	return paths
 }
+
+func extractRubyConstraintFromGemfile(ctx *generate.GenerateContext) string {
+	gemfile, err := ctx.App.ReadFile("Gemfile")
+	if err != nil {
+		return ""
+	}
+	matches := gemfileVersionRegex.FindStringSubmatch(string(gemfile))
+	if len(matches) > 1 {
+		return matches[1]
+	}
+	return ""
+}

core/providers/ruby/ruby_test.go

@@ -3,6 +3,7 @@ package ruby
 import (
 	"testing"
 
+	"github.com/Masterminds/semver/v3"
 	"github.com/stretchr/testify/require"
 
 	testingUtils "github.com/railwayapp/railpack/core/testing"
@@ -36,3 +37,83 @@ func TestDetect(t *testing.T) {
 		})
 	}
 }
+
+func TestRubyVersionDetection_Examples(t *testing.T) {
+	cases := []struct {
+		desc   string
+		path   string
+		expect string
+	}{
+		{
+			desc:   ".ruby-version present (ruby-3)",
+			path:   "../../../examples/ruby-3",
+			expect: "3.2.1",
+		},
+		{
+			desc:   "Gemfile.lock with version (ruby-vanilla)",
+			path:   "../../../examples/ruby-vanilla",
+			expect: "3.4.2",
+		},
+		{
+			desc:   "Gemfile with version constraint < 3.5.0 (ruby-no-version)",
+			path:   "../../../examples/ruby-no-version",
+			expect: "3.4.4",
+		},
+		{
+			desc:   "Gemfile with single version constraint (ruby-single-version)",
+			path:   "../../../examples/ruby-single-version",
+			expect: "3.4.2",
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.desc, func(t *testing.T) {
+			ctx := testingUtils.CreateGenerateContext(t, c.path)
+			miseStep := ctx.GetMiseStepBuilder()
+			provider := RubyProvider{}
+			provider.InstallMisePackages(ctx, miseStep)
+
+			resolvedPackages, err := miseStep.Resolver.ResolvePackages()
+			require.NoError(t, err)
+
+			resolvedPkg, exists := resolvedPackages["ruby"]
+			if !exists {
+				t.Fatalf("ruby package not found in resolved packages")
+			}
+
+			if resolvedPkg.ResolvedVersion == nil {
+				t.Fatalf("ruby package version not resolved")
+			}
+
+			require.Equal(t, c.expect, *resolvedPkg.ResolvedVersion)
+		})
+	}
+}
+
+func TestRubyVersionConstraintResolution(t *testing.T) {
+	t.Run("constraint_resolution_works", func(t *testing.T) {
+		ctx := testingUtils.CreateGenerateContext(t, "../../../examples/ruby-no-version")
+
+		miseStep := ctx.GetMiseStepBuilder()
+		provider := RubyProvider{}
+		provider.InstallMisePackages(ctx, miseStep)
+
+		resolvedPackages, err := miseStep.Resolver.ResolvePackages()
+		require.NoError(t, err)
+
+		resolvedPkg, exists := resolvedPackages["ruby"]
+		require.True(t, exists, "ruby package should be found in resolved packages")
+		require.NotNil(t, resolvedPkg.ResolvedVersion, "ruby package version should be resolved")
+
+		actualVersion := *resolvedPkg.ResolvedVersion
+
+		v, err := semver.NewVersion(actualVersion)
+		require.NoError(t, err)
+		require.True(t, v.Major() == 3 && v.Minor() >= 2 && v.Minor() < 5,
+			"Resolved version %s should be >= 3.2.0 and < 3.5.0", actualVersion)
+
+		require.True(t, v.Minor() >= 4, "Should resolve to a recent version, got %s", actualVersion)
+
+		require.Equal(t, "3.4.4", actualVersion, "Should resolve to the highest stable version under 3.5.0")
+	})
+}

core/resolver/resolver.go

@@ -156,3 +156,7 @@ func (r *Resolver) SetVersionAvailable(ref PackageRef, isVersionAvailable func(v
 func (r *Resolver) SetSkipMiseInstall(ref PackageRef, skipMiseInstall bool) {
 	r.packages[ref.Name].SkipMiseInstall = skipMiseInstall
 }
+
+func (r *Resolver) GetMise() *mise.Mise {
+	return r.mise
+}

examples/ruby-no-version/Gemfile

@@ -1,5 +1,5 @@
-
 source 'https://rubygems.org'
+ruby '>= 3.2.0', '< 3.5.0'
 
+gem 'puma', '~> 5.6'
 gem 'sinatra'
-gem "puma", "~> 5.6"

examples/ruby-single-version/Gemfile

@@ -0,0 +1,5 @@
+source 'https://rubygems.org'
+ruby '3.4.2'
+
+gem 'puma', '~> 5.6'
+gem 'sinatra'

examples/ruby-single-version/Gemfile.lock

@@ -0,0 +1,20 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    puma (5.6.7)
+      nio4r (~> 2.0)
+    sinatra (3.0.5)
+      mustermann (~> 3.0)
+      rack (~> 3.0)
+      rack-protection (= 3.0.5)
+      tilt (~> 2.0)
+
+PLATFORMS
+  x86_64-linux
+
+DEPENDENCIES
+  puma (~> 5.6)
+  sinatra
+
+BUNDLED WITH
+   2.4.22 

examples/ruby-single-version/app.rb

@@ -0,0 +1,5 @@
+require 'sinatra'
+
+get '/' do
+  "Hello from Ruby #{RUBY_VERSION}!"
+end

examples/ruby-single-version/config.ru

@@ -0,0 +1,2 @@
+require './app'
+run Sinatra::Application