[Gemspec] - Allow lower faraday versions (#173)

# Description

In reference to issue: #172 -
this CR exists to allow for applications requiring different, lower
Faraday versions to integrate with this Gem.

# Changes Made

1. Updated the gemspec for Faraday and its dependencies to allow use of
lower versions in case of a conflict.
2. Updated CICD.yml workflow to validate that lower Faraday versions
work.
3. Specs failed on lower Faraday versions so I updated
`lib/ruby_llm/streaming.rb` to allow for legacy Faraday versions to
stream responses as well. Could use feedback definitely in case this
breaks logic in a way you all are uncomfy with.

# Testing

I ran manually rspec with Faraday Version 2.13.1 and 1.10.3, here are
the results prior to CI/CD integration in this repo:

| Faraday Version   |    Validate Gem Install        |  Test Results |
|----------|:-------------:|------:|
| 1.10.3 | ![Screenshot 2025-05-14 at 12 52
57 PM](https://github.com/user-attachments/assets/5233a968-c37f-4de3-9ef0-bdaad17a3a2e)
| ![Screenshot 2025-05-14 at 12 53
03 PM](https://github.com/user-attachments/assets/b21f830f-732a-4aef-94fa-5db07a2be8f8)
|
| 2.13.1 | ![Screenshot 2025-05-14 at 12 52
39 PM](https://github.com/user-attachments/assets/78c81a09-0bed-4f10-bc72-c8e76d16df08)
| ![Screenshot 2025-05-14 at 12 52
46 PM](https://github.com/user-attachments/assets/ded40e55-7296-49a8-b4c8-b11a49ad6726)
|

Author: itstheraj

.github/workflows/cicd.yml

@@ -61,6 +61,11 @@ jobs:
         files: ./coverage/coverage.xml
         fail_ci_if_error: false
 
+    - name: Run the test suite with lower Faraday versions
+      run: FARADAY_VERSION=1.10.3 bundle install && bundle exec rspec
+      env:
+        OLLAMA_API_BASE: http://localhost:11434/v1 # dummy
+
   publish:
     name: Build + Publish
     needs: test

lib/ruby_llm/streaming.rb

@@ -12,9 +12,18 @@ def stream_response(connection, payload, &block)
       accumulator = StreamAccumulator.new
 
       connection.post stream_url, payload do |req|
-        req.options.on_data = handle_stream do |chunk|
-          accumulator.add chunk
-          block.call chunk
+        if req.options.respond_to?(:on_data)
+          # Handle Faraday 2.x streaming with on_data method
+          req.options.on_data = handle_stream do |chunk|
+            accumulator.add chunk
+            block.call chunk
+          end
+        else
+          # Handle Faraday 1.x streaming with :on_data key
+          req.options[:on_data] = handle_stream do |chunk|
+            accumulator.add chunk
+            block.call chunk
+          end
         end
       end
 
@@ -29,19 +38,45 @@ def handle_stream(&block)
 
     private
 
-    def to_json_stream(&block)
+    def to_json_stream(&)
       buffer = String.new
       parser = EventStreamParser::Parser.new
 
-      proc do |chunk, _bytes, env|
-        RubyLLM.logger.debug "Received chunk: #{chunk}"
+      create_stream_processor(parser, buffer, &)
+    end
 
-        if error_chunk?(chunk)
-          handle_error_chunk(chunk, env)
-        elsif env&.status != 200
-          handle_failed_response(chunk, buffer, env)
+    def create_stream_processor(parser, buffer, &)
+      if Faraday::VERSION.start_with?('1')
+        # Faraday 1.x: on_data receives (chunk, size)
+        legacy_stream_processor(parser, &)
+      else
+        # Faraday 2.x: on_data receives (chunk, bytes, env)
+        stream_processor(parser, buffer, &)
+      end
+    end
+
+    def process_stream_chunk(chunk, parser, _env, &)
+      RubyLLM.logger.debug "Received chunk: #{chunk}"
+
+      if error_chunk?(chunk)
+        handle_error_chunk(chunk, nil)
+      else
+        yield handle_sse(chunk, parser, nil, &)
+      end
+    end
+
+    def legacy_stream_processor(parser, &block)
+      proc do |chunk, _size|
+        process_stream_chunk(chunk, parser, nil, &block)
+      end
+    end
+
+    def stream_processor(parser, buffer, &block)
+      proc do |chunk, _bytes, env|
+        if env&.status == 200
+          process_stream_chunk(chunk, parser, env, &block)
         else
-          yield handle_sse(chunk, parser, env, &block)
+          handle_failed_response(chunk, buffer, env)
         end
       end
     end

ruby_llm.gemspec

@@ -36,10 +36,10 @@ Gem::Specification.new do |spec|
   # Runtime dependencies
   spec.add_dependency 'base64'
   spec.add_dependency 'event_stream_parser', '~> 1'
-  spec.add_dependency 'faraday', '~> 2'
-  spec.add_dependency 'faraday-multipart', '~> 1'
-  spec.add_dependency 'faraday-net_http', '~> 3'
-  spec.add_dependency 'faraday-retry', '~> 2'
+  spec.add_dependency 'faraday', ENV['FARADAY_VERSION'] || '>= 1.10.0'
+  spec.add_dependency 'faraday-multipart', '>= 1'
+  spec.add_dependency 'faraday-net_http', '>= 1'
+  spec.add_dependency 'faraday-retry', '>= 1'
   spec.add_dependency 'marcel', '~> 1.0'
   spec.add_dependency 'zeitwerk', '~> 2'
 end