Allow file upload to accept File instance

Author: simonx1

lib/openai/files.rb

@@ -1,5 +1,8 @@
 module OpenAI
   class Files
+
+    PURPOSES = %w[fine-tune assistants].freeze
+
     def initialize(client:)
       @client = client
     end
@@ -9,12 +12,17 @@ def list
     end
 
     def upload(parameters: {})
-      validate(file: parameters[:file]) if parameters[:file].include?(".jsonl")
+      file_input = parameters[:file]
+      file = prepare_file_input(file_input: file_input)
+
+      validate(file: file, purpose: parameters[:purpose], file_input: file_input)
 
       @client.multipart_post(
         path: "/files",
-        parameters: parameters.merge(file: File.open(parameters[:file]))
+        parameters: parameters.merge(file: file)
       )
+    ensure
+      file.close if file.is_a?(File)
     end
 
     def retrieve(id:)
@@ -31,12 +39,31 @@ def delete(id:)
 
     private
 
-    def validate(file:)
-      File.open(file).each_line.with_index do |line, index|
+    def prepare_file_input(file_input:)
+      if file_input.is_a?(String)
+        File.open(file_input)
+      elsif file_input.respond_to?(:read) && file_input.respond_to?(:rewind)
+        file_input
+      else
+        raise ArgumentError, "Invalid file input"
+      end
+    end
+
+    def validate(file:, purpose:, file_input:)
+      raise ArgumentError, "`file` is required" if file.nil?
+      raise ArgumentError, "`purpose` must one of `#{PURPOSES.join(',')}`" unless PURPOSES.include?(purpose)
+
+      validate_jsonl(file: file) if file_input.is_a?(String) && file_input.end_with?(".jsonl")
+    end
+
+    def validate_jsonl(file:)
+      file.each_line.with_index do |line, index|
         JSON.parse(line)
       rescue JSON::ParserError => e
         raise JSON::ParserError, "#{e.message} - found on line #{index + 1} of #{file}"
       end
+    ensure
+      file.rewind
     end
   end
 end

spec/openai/client/files_spec.rb

@@ -24,6 +24,20 @@
 
         it { expect { upload }.to raise_error(JSON::ParserError) }
       end
+
+      context "with an invalid purpose" do
+        let(:upload_purpose) { "invalid" }
+
+        it { expect { upload }.to raise_error(ArgumentError) }
+      end
+
+      context "with a file content" do
+        let(:file) { File.open(File.join(RSPEC_ROOT, "fixtures/files", filename)) }
+
+        it "succeeds" do
+          expect(upload["filename"]).to eq(filename)
+        end
+      end
     end
 
     describe "#list" do