Add missing ruby platform gem

Author: Taucher2003

gem/lib/triangulum/validation.rb

@@ -19,6 +19,8 @@ class BunNotFound < Triangulum::Error
       Gem::Platform.match_gem?(platform, Gem::Platform.local.to_s)
     end
 
+    IS_RUBY_PLATFORM_GEM = Dir.glob(File.expand_path('../../exe/*/bun', __dir__)).empty?
+
     attr_reader :flow, :runtime_function_definitions, :data_types
 
     def initialize(flow, runtime_function_definitions, data_types)
@@ -38,10 +40,8 @@ def validate
     private
 
     def run_ts_triangulum(input)
-      raise BunNotFound, "No bundled bun binary found for #{Gem::Platform.local}" if BUN_EXE.nil?
-
       stdout_s, stderr_s, status = Open3.capture3(
-        BUN_EXE, 'run', ENTRYPOINT,
+        bun, 'run', ENTRYPOINT,
         stdin_data: input
       )
 
@@ -88,5 +88,15 @@ def parse_output(output)
         end
       )
     end
+
+    def bun
+      if IS_RUBY_PLATFORM_GEM
+        'bun'
+      else
+        raise BunNotFound, "No bundled bun binary found for #{Gem::Platform.local}" if BUN_EXE.nil?
+
+        BUN_EXE
+      end
+    end
   end
 end

gem/rakelib/package.rake

@@ -19,6 +19,11 @@ exepaths = []
 
 TRIANGULUM_GEMSPEC = Bundler.load_gemspec('triangulum.gemspec')
 
+ruby_gem_path = Gem::PackageTask.new(TRIANGULUM_GEMSPEC).define
+
+desc 'Build the ruby (platform-independent) gem'
+task 'gem:ruby' => [ruby_gem_path]
+
 BUN_PLATFORMS.each do |platform, (zip_filename, expected_checksum)|
   TRIANGULUM_GEMSPEC.dup.tap do |gemspec|
     exedir = File.join('exe', platform)