Allow application/x-www-form-url_encoded POST requests to use file ob…

…jects as the request body (#1415)

lib/faraday/request/url_encoded.rb

@@ -31,7 +31,9 @@ def match_content_type(env)
         return unless process_request?(env)
 
         env.request_headers[CONTENT_TYPE] ||= self.class.mime_type
-        yield(env.body) unless env.body.respond_to?(:to_str)
+        return if env.body.respond_to?(:to_str) || env.body.respond_to?(:read)
+
+        yield(env.body)
       end
 
       # @param env [Faraday::Env]

spec/faraday/request/url_encoded_spec.rb

@@ -1,13 +1,19 @@
 # frozen_string_literal: true
 
+require 'stringio'
+
 RSpec.describe Faraday::Request::UrlEncoded do
   let(:conn) do
     Faraday.new do |b|
       b.request :url_encoded
       b.adapter :test do |stub|
         stub.post('/echo') do |env|
           posted_as = env[:request_headers]['Content-Type']
-          [200, { 'Content-Type' => posted_as }, env[:body]]
+          body = env[:body]
+          if body.respond_to?(:read)
+            body = body.read
+          end
+          [200, { 'Content-Type' => posted_as }, body]
         end
       end
     end
@@ -67,6 +73,11 @@
     expect(response.body).to eq('a%5Bb%5D%5Bc%5D%5B%5D=d')
   end
 
+  it 'works with files' do
+    response = conn.post('/echo', StringIO.new('str=apple'))
+    expect(response.body).to eq('str=apple')
+  end
+
   context 'customising default_space_encoding' do
     around do |example|
       Faraday::Utils.default_space_encoding = '%20'