refactor: Introducing Models.resolve to simplify and unify model resolution in chat, embedding, and image methods

Now `assume_model_exists` can be used in `paint` and `embed` methods too.

Author: crmne

lib/ruby_llm/chat.rb

@@ -60,20 +60,8 @@ def with_tools(*tools)
       self
     end
 
-    def with_model(model_id, provider: nil, assume_exists: false) # rubocop:disable Metrics/AbcSize,Metrics/MethodLength
-      assume_exists = true if provider && Provider.providers[provider.to_sym].local?
-
-      if assume_exists
-        raise ArgumentError, 'Provider must be specified if assume_exists is true' unless provider
-
-        @provider = Provider.providers[provider.to_sym] || raise(Error, "Unknown provider: #{provider.to_sym}")
-        @model = Struct.new(:id, :provider, :supports_functions, :supports_vision).new(model_id, provider, true, true)
-        RubyLLM.logger.warn "Assuming model '#{model_id}' exists for provider '#{provider}'. " \
-                            'Capabilities may not be accurately reflected.'
-      else
-        @model = Models.find model_id, provider
-        @provider = Provider.providers[@model.provider.to_sym] || raise(Error, "Unknown provider: #{@model.provider}")
-      end
+    def with_model(model_id, provider: nil, assume_exists: false)
+      @model, @provider = Models.resolve(model_id, provider:, assume_exists:)
       self
     end
 

lib/ruby_llm/embedding.rb

@@ -12,12 +12,17 @@ def initialize(vectors:, model:, input_tokens: 0)
       @input_tokens = input_tokens
     end
 
-    def self.embed(text, model: nil, provider: nil, context: nil, dimensions: nil)
+    def self.embed(text, # rubocop:disable Metrics/ParameterLists,Metrics/CyclomaticComplexity
+                   model: nil,
+                   provider: nil,
+                   assume_model_exists: false,
+                   context: nil,
+                   dimensions: nil)
       config = context&.config || RubyLLM.config
-      model_id = model || config.default_embedding_model
-      Models.find(model_id, provider)
+      model, provider = Models.resolve(model, provider: provider, assume_exists: assume_model_exists) if model
+      model_id = model&.id || config.default_embedding_model
 
-      provider = Provider.for(model_id)
+      provider = Provider.for(model_id) if provider.nil?
       connection = context ? context.connection_for(provider) : provider.connection(config)
       provider.embed(text, model: model_id, connection:, dimensions:)
     end

lib/ruby_llm/image.rb

@@ -36,12 +36,17 @@ def save(path)
       path
     end
 
-    def self.paint(prompt, model: nil, provider: nil, size: '1024x1024', context: nil)
+    def self.paint(prompt, # rubocop:disable Metrics/ParameterLists,Metrics/CyclomaticComplexity
+                   model: nil,
+                   provider: nil,
+                   assume_model_exists: false,
+                   size: '1024x1024',
+                   context: nil)
       config = context&.config || RubyLLM.config
-      model_id = model || config.default_image_model
-      Models.find(model_id, provider) # Validate model exists
+      model, provider = Models.resolve(model, provider: provider, assume_exists: assume_model_exists) if model
+      model_id = model&.id || config.default_image_model
 
-      provider = Provider.for(model_id)
+      provider = Provider.for(model_id) if provider.nil?
       connection = context ? context.connection_for(provider) : provider.connection(config)
       provider.paint(prompt, model: model_id, size:, connection:)
     end

lib/ruby_llm/models.rb

@@ -9,7 +9,7 @@ module RubyLLM
   #   RubyLLM.models.chat_models                          # Models that support chat
   #   RubyLLM.models.by_provider('openai').chat_models    # OpenAI chat models
   #   RubyLLM.models.find('claude-3')                     # Get info about a specific model
-  class Models
+  class Models # rubocop:disable Metrics/ClassLength
     include Enumerable
 
     # Delegate class methods to the singleton instance
@@ -46,6 +46,23 @@ def refresh! # rubocop:disable Metrics/AbcSize,Metrics/CyclomaticComplexity,Metr
         @instance
       end
 
+      def resolve(model_id, provider: nil, assume_exists: false) # rubocop:disable Metrics/AbcSize,Metrics/MethodLength
+        assume_exists = true if provider && Provider.providers[provider.to_sym].local?
+
+        if assume_exists
+          raise ArgumentError, 'Provider must be specified if assume_exists is true' unless provider
+
+          provider = Provider.providers[provider.to_sym] || raise(Error, "Unknown provider: #{provider.to_sym}")
+          model = Struct.new(:id, :provider, :supports_functions, :supports_vision).new(model_id, provider, true, true)
+          RubyLLM.logger.warn "Assuming model '#{model_id}' exists for provider '#{provider}'. " \
+                              'Capabilities may not be accurately reflected.'
+        else
+          model = Models.find model_id, provider
+          provider = Provider.providers[model.provider.to_sym] || raise(Error, "Unknown provider: #{model.provider}")
+        end
+        [model, provider]
+      end
+
       def method_missing(method, ...)
         if instance.respond_to?(method)
           instance.send(method, ...)

spec/ruby_llm/chat_assume_model_exists_spec.rb

@@ -8,7 +8,7 @@
   describe '#assume_model_exists' do
     let(:real_model) { 'gpt-4.1-nano' }
     let(:custom_model) { 'my-custom-model' }
-    let(:provider) { :openai }
+    let(:provider) { 'openai' }
     # Keep a reference to the original models for cleanup
     let!(:original_models) { RubyLLM::Models.instance.all.dup }
 
@@ -33,7 +33,7 @@
       )
 
       expect(chat.model.id).to eq(custom_model)
-      expect(chat.model.provider).to eq(provider)
+      expect(chat.model.provider.slug).to eq(provider)
     end
 
     it 'works with RubyLLM.chat convenience method' do # rubocop:disable RSpec/ExampleLength
@@ -74,7 +74,7 @@
       chat.with_model(custom_model, provider: provider, assume_exists: true)
 
       expect(chat.model.id).to eq(custom_model)
-      expect(chat.model.provider).to eq(provider)
+      expect(chat.model.provider.slug).to eq(provider)
     end
   end
 end