Fix Encoding::CompatibilityError: Unicode Normalization not appropriate for ASCII-8BIT (#218)

Encoding::CompatibilityError: Unicode Normalization not appropriate for
ASCII-8BIT is introduced after #215, commit:
d34592e

The fix is copy from:
knu/ruby-domain_name#27

---------

Co-authored-by: Carmine Paolino <carmine@paolino.me>

Author: Eric-Guo

lib/ruby_llm/tool.rb

@@ -49,14 +49,14 @@ def parameters
     end
 
     def name
-      self.class.name
-          .unicode_normalize(:nfkd)
-          .encode('ASCII', replace: '')
-          .gsub(/[^a-zA-Z0-9_-]/, '-')
-          .gsub(/([A-Z]+)([A-Z][a-z])/, '\1_\2')
-          .gsub(/([a-z\d])([A-Z])/, '\1_\2')
-          .downcase
-          .delete_suffix('_tool')
+      klass_name = self.class.name
+      normalized = klass_name.to_s.dup.force_encoding('UTF-8').unicode_normalize(:nfkd)
+      normalized.encode('ASCII', replace: '')
+                .gsub(/[^a-zA-Z0-9_-]/, '-')
+                .gsub(/([A-Z]+)([A-Z][a-z])/, '\1_\2')
+                .gsub(/([a-z\d])([A-Z])/, '\1_\2')
+                .downcase
+                .delete_suffix('_tool')
     end
 
     def description

spec/ruby_llm/tool_spec.rb

@@ -32,5 +32,13 @@
       stub_const('TestModule::SampleTool', Class.new(described_class))
       expect(TestModule::SampleTool.new.name).to eq('test_module--sample')
     end
+
+    it 'handles ASCII-8BIT encoded class names without raising Encoding::CompatibilityError' do
+      # This simulates a class name that is ASCII-8BIT encoded
+      tool_class = Class.new(described_class)
+      ascii_8bit_name = 'SampleTool'.dup.force_encoding('ASCII-8BIT')
+      allow(tool_class).to receive(:name).and_return(ascii_8bit_name)
+      expect(tool_class.new.name).to eq('sample')
+    end
   end
 end