Adds request_body_multipart method which enables schema properties to be written for multipart upload body

Will inspect the provided hash and add the property file_name to the parameters collection so upload and 3.0 output will work properly

rswag-specs/lib/rswag/specs/example_group_helpers.rb

@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+require 'hashie'
 
 module Rswag
   module Specs
@@ -75,6 +76,30 @@ module Rswag
         end
       end
 
+      def request_body_multipart(schema:, description: nil)
+        content_hash = { 'multipart/form-data' => { schema: schema }}
+        request_body(description: description, content: content_hash)
+
+        schema.extend(Hashie::Extensions::DeepLocate)
+        file_properties = schema.deep_locate -> (_k, v, _obj) { v == :binary } 
+
+        hash_locator = []
+
+        file_properties.each do |match|
+          hash_match = schema.deep_locate -> (_k, v, _obj) { v == match }
+          hash_locator.concat(hash_match) unless hash_match.empty?
+        end
+
+        property_hashes = hash_locator.flat_map do |locator|
+          locator.select { |_k,v| file_properties.include?(v) }
+        end
+
+        property_hashes.each do |property_hash|
+          file_name = property_hash.keys.first
+          parameter name: file_name, in: :formData, type: :file, required: true
+        end
+      end
+
       def parameter(attributes)
         if attributes[:in] && attributes[:in].to_sym == :path
           attributes[:required] = true

rswag-specs/lib/rswag/specs/swagger_formatter.rb

@@ -44,7 +44,7 @@ module Rswag
                   value[:requestBody][:content]['application/json'].merge!(schema: schema_param[:schema])
                 end
 
-                value[:parameters].reject! { |p| p[:in] == :body }
+                value[:parameters].reject! { |p| p[:in] == :body || p[:in] == :formData }
                 value[:parameters].each { |p| p.delete(:type) }
                 value[:headers].each { |p| p.delete(:type)}  if value[:headers]
               end