Fix #add_attachment multipart upload with Faraday

lib/trello/card.rb

@@ -273,7 +273,7 @@ def add_attachment(attachment, name = '')
       # Is it a file object or a string (url)?
       if attachment.respond_to?(:path) && attachment.respond_to?(:read)
         client.post("/cards/#{id}/attachments", {
-            file: attachment,
+            file: Trello::TInternet.multipart_file(attachment),
             name: name
           })
       else

lib/trello/net.rb

@@ -7,6 +7,10 @@ class << self
       def execute(request)
         Trello.http_client.execute(request)
       end
+
+      def multipart_file(file)
+        Trello.http_client.multipart_file(file)
+      end
     end
   end
 end

lib/trello/net/faraday.rb

@@ -4,13 +4,23 @@ class TInternet
       class << self
         begin
           require 'faraday'
+          require 'faraday/multipart'
+          require 'mime/types'
         rescue LoadError
         end
 
         def execute(request)
           try_execute request
         end
 
+        def multipart_file(file)
+          Faraday::Multipart::FilePart.new(
+            file,
+            content_type(file),
+            filename(file)
+          )
+        end
+
         private
 
         def try_execute(request)
@@ -33,13 +43,34 @@ def execute_core(request)
             request: { timeout: 10 }
           ) do |faraday|
             faraday.response :raise_error
+            faraday.request :multipart
             faraday.request :json
           end
 
           conn.send(request.verb) do |req|
             req.body = request.body
           end
         end
+
+        def content_type(file)
+          return file.content_type if file.respond_to?(:content_type)
+
+          mime = MIME::Types.type_for file.path
+          if mime.empty?
+            'text/plain'
+          else
+            mime[0].content_type
+          end
+        end
+
+        def filename(file)
+          if file.respond_to?(:original_filename)
+            file.original_filename
+          else
+            File.basename(file.path)
+          end
+        end
+
       end
     end
   end

lib/trello/net/rest_client.rb

@@ -11,6 +11,10 @@ def execute(request)
           try_execute request
         end
 
+        def multipart_file(file)
+          file
+        end
+
         private
 
         def try_execute(request)

ruby-trello.gemspec

@@ -25,4 +25,6 @@ Gem::Specification.new do |s|
   s.add_dependency 'json', '>= 2.3.0'
   s.add_dependency 'oauth', '>= 0.4.5'
   s.add_dependency 'faraday', '~> 2.0'
+  s.add_dependency 'faraday-multipart', '~> 1.0'
+  s.add_dependency('mime-types', '>= 3.0', '< 4.0')
 end

spec/card_spec.rb

@@ -734,7 +734,7 @@ module Trello
 
         allow(client)
           .to receive(:post)
-          .with("/cards/abcdef123456789123456789/attachments", { file: f, name: ''  })
+          .with("/cards/abcdef123456789123456789/attachments", { file: instance_of(Multipart::Post::UploadIO), name: ''  })
           .and_return "not important"
 
         card.add_attachment(f)

spec/integration/card/add_and_remove_attachment_spec.rb

@@ -7,7 +7,8 @@
 
   describe '#add_attachment' do
     it 'can success add an attachment(file) on a card' do
-      VCR.use_cassette('can_add_a_file_on_a_card') do
+      cassette_name = Trello.http_client == "rest-client" ? "can_add_a_file_on_a_card" : "can_add_a_file_on_a_card_with_farady"
+      VCR.use_cassette(cassette_name) do
         card = Trello::Card.find('5e95d1b4f43f9a06497f17f7')
         file = File.new('spec/integration/card/add_and_remove_attachment_spec.rb', 'r')