add faraday adapter customization

lib/facebook_ads.rb

@@ -45,9 +45,9 @@ def configure
 
   require 'facebook_ads/ruby2patch'
 
+  require 'facebook_ads/session'
   require 'facebook_ads/config'
   require 'facebook_ads/errors'
-  require 'facebook_ads/session'
   require 'facebook_ads/fields'
   require 'facebook_ads/edge'
   require 'facebook_ads/param_set'

lib/facebook_ads/config.rb

@@ -35,6 +35,7 @@ def self.setting(name, default = nil)
     setting :app_secret, ENV['FB_APP_SECRET']
     setting :crash_logging_enabled, true
     setting :log_api_bodies, false
+    setting :faraday_adapter, Faraday.default_adapter
 
     def logger=(logger)
       Utils.logger = logger

lib/facebook_ads/session.rb

@@ -66,7 +66,7 @@ def api_conn
         faraday.request  :url_encoded
 
         faraday.response :logger, Utils.logger, bodies: FacebookAds.config.log_api_bodies
-        faraday.adapter  Faraday.default_adapter
+        faraday.adapter  FacebookAds.config.faraday_adapter
       end
     end
 

spec/config_spec.rb

@@ -0,0 +1,42 @@
+# Copyright (c) 2017-present, Facebook, Inc. All rights reserved.
+#
+# You are hereby granted a non-exclusive, worldwide, royalty-free license to use,
+# copy, modify, and distribute this software in source code or binary form for use
+# in connection with the web services and APIs provided by Facebook.
+#
+# As with any software that integrates with the Facebook platform, your use of
+# this software is subject to the Facebook Platform Policy
+# [http://developers.facebook.com/policy/]. This copyright notice shall be
+# included in all copies or substantial portions of the software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+# FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+# COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+# IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+
+RSpec.describe FacebookAds::Config do
+  it 'provides with default config' do
+    expect(subject).to have_attributes(
+     server_host: FacebookAds::DEFAULT_HOST,
+     api_version: FacebookAds::DEFAULT_API_VERSION,
+     access_token: ENV['FB_ACCESS_TOKEN'],
+     app_secret: ENV['FB_APP_SECRET'],
+     crash_logging_enabled: true,
+     log_api_bodies: false,
+     faraday_adapter: Faraday.default_adapter
+    )
+  end
+
+  context 'custom config' do
+    let(:fake_adapter) { double(:fake_adapter) }
+
+    it 'saves custom values' do
+      subject.faraday_adapter = fake_adapter
+
+      expect(subject.faraday_adapter).to eq fake_adapter
+    end
+  end
+end