[Ruby][faraday] fix download_file

modules/openapi-generator/src/main/resources/ruby-client/api_client.mustache

@@ -71,7 +71,8 @@ module {{moduleName}}
       {{/isFaraday}}
       {{#isFaraday}}
       if return_type == 'File'
-        @tempfile.write(@stream)
+        @tempfile = Tempfile.open('download-', @config.temp_folder_path, encoding: body.encoding)
+        @tempfile.write(@stream.join.force_encoding(body.encoding))
         @tempfile.close
         @config.logger.info "Temp file written to #{@tempfile.path}, please copy the file to a proper folder "\
                             "with e.g. `FileUtils.cp(tempfile.path, '/new/file/path')` otherwise the temp file "\

modules/openapi-generator/src/main/resources/ruby-client/api_client_faraday_partial.mustache

@@ -128,40 +128,11 @@
       data
     end
 
-    # Save response body into a file in (the defined) temporary folder, using the filename
-    # from the "Content-Disposition" header if provided, otherwise a random filename.
-    # The response body is written to the file in chunks in order to handle files which
-    # size is larger than maximum Ruby String or even larger than the maximum memory a Ruby
-    # process can use.
-    #
-    # @see Configuration#temp_folder_path
     def download_file(request)
-      tempfile = nil
-      encoding = nil
-      request.headers do |response|
-        content_disposition = response.headers['Content-Disposition']
-        if content_disposition && content_disposition =~ /filename=/i
-          filename = content_disposition[/filename=['"]?([^'"\s]+)['"]?/, 1]
-          prefix = sanitize_filename(filename)
-        else
-          prefix = 'download-'
-        end
-        prefix = prefix + '-' unless prefix.end_with?('-')
-        encoding = response.body.encoding
-        tempfile = Tempfile.open(prefix, @config.temp_folder_path, encoding: encoding)
-        @tempfile = tempfile
-      end
-
-      if tempfile.nil?
-        tempfile = Tempfile.open('download-', @config.temp_folder_path)
-        @tempfile = tempfile
-      end
-
       @stream = []
 
       # handle streaming Responses
       request.options.on_data = Proc.new do |chunk, overall_received_bytes|
         @stream << chunk
       end
-
     end

samples/client/petstore/ruby-faraday/lib/petstore/api_client.rb

@@ -172,42 +172,13 @@ def build_request_body(header_params, form_params, body)
       data
     end
 
-    # Save response body into a file in (the defined) temporary folder, using the filename
-    # from the "Content-Disposition" header if provided, otherwise a random filename.
-    # The response body is written to the file in chunks in order to handle files which
-    # size is larger than maximum Ruby String or even larger than the maximum memory a Ruby
-    # process can use.
-    #
-    # @see Configuration#temp_folder_path
     def download_file(request)
-      tempfile = nil
-      encoding = nil
-      request.headers do |response|
-        content_disposition = response.headers['Content-Disposition']
-        if content_disposition && content_disposition =~ /filename=/i
-          filename = content_disposition[/filename=['"]?([^'"\s]+)['"]?/, 1]
-          prefix = sanitize_filename(filename)
-        else
-          prefix = 'download-'
-        end
-        prefix = prefix + '-' unless prefix.end_with?('-')
-        encoding = response.body.encoding
-        tempfile = Tempfile.open(prefix, @config.temp_folder_path, encoding: encoding)
-        @tempfile = tempfile
-      end
-
-      if tempfile.nil?
-        tempfile = Tempfile.open('download-', @config.temp_folder_path)
-        @tempfile = tempfile
-      end
-
       @stream = []
 
       # handle streaming Responses
       request.options.on_data = Proc.new do |chunk, overall_received_bytes|
         @stream << chunk
       end
-
     end
 
     # Check if the given MIME is a JSON MIME.
@@ -232,7 +203,8 @@ def deserialize(response, return_type)
       # handle file downloading - return the File instance processed in request callbacks
       # note that response body is empty when the file is written in chunks in request on_body callback
       if return_type == 'File'
-        @tempfile.write(@stream)
+        @tempfile = Tempfile.open('download-', @config.temp_folder_path, encoding: body.encoding)
+        @tempfile.write(@stream.join.force_encoding(body.encoding))
         @tempfile.close
         @config.logger.info "Temp file written to #{@tempfile.path}, please copy the file to a proper folder "\
                             "with e.g. `FileUtils.cp(tempfile.path, '/new/file/path')` otherwise the temp file "\