Extract external service dependencies into method calls, get first real test

Author: edgenard

refactoring_external_service/youtube_video_list.rb

@@ -2,7 +2,25 @@ class VideoService
   def video_list
     @video_list = get_current_video_list
     ids = @video_list.map{|v| v['youtubeID']}
-    # NOTE: External Service
+    response = get_youtube_stats_on_videos(ids)
+    ids.each do |id|
+      video = @video_list.find{|v| id == v['youtubeID']}
+      youtube_record = response['items'].find{|v| id == v['id']}
+      video['views'] = youtube_record['statistics']['viewCount'].to_i
+      days_available = Date.today - Date.parse(youtube_record['snippet']['publishedAt'])
+      video['monthlyViews'] = video['views'] * 365.0 / days_available / 12
+    end
+    return JSON.dump(@video_list)
+  end
+
+  private
+  
+  def get_current_video_list
+    video_list_json = File.read('videos.json')
+    JSON.parse(video_list_json)
+  end
+
+  def get_youtube_stats_on_videos(youtube_ids)
     client = GoogleAuthorizer.new(
       token_key: 'api-youtube',
       application_name: 'Gateway Youtube Example',
@@ -13,25 +31,11 @@ def video_list
     request = {
       api_method: youtube.videos.list,# NOTE: External Service
       parameters: {
-        id: ids.join(","),
+        id: youtube_ids.join(","),
         part: 'snippet, contentDetails, statistics',
       }
     }
     # NOTE: External Service 
     response = JSON.parse(client.execute!(request).body)
-    ids.each do |id|
-      video = @video_list.find{|v| id == v['youtubeID']}
-      youtube_record = response['items'].find{|v| id == v['id']}
-      video['views'] = youtube_record['statistics']['viewCount'].to_i
-      days_available = Date.today - Date.parse(youtube_record['snippet']['publishedAt'])
-      video['monthlyViews'] = video['views'] * 365.0 / days_available / 12
-    end
-    return JSON.dump(@video_list)
-  end
-
-  private
-  def get_current_video_list
-    video_list_json = File.read('videos.json')
-    JSON.parse(video_list_json)
   end
 end

refactoring_external_service/youtube_video_list_spec.rb

@@ -1,15 +1,31 @@
 require 'minitest/autorun'
 require './youtube_video_list'
 require 'json'
+require 'date'
 
 class VideoServiceTest < MiniTest::Test
 
     def test_video_list_returns_video_list
         video_service = VideoService.new
-        video_array = [{'youtubeId': 'blahblahblah', 'views': 3, 'monthlyViews': 1}]
+        video_array = [{'youtubeID' => 'blahblahblah', 'views' => 3, 'monthlyViews' => 3}]
+        youtube_response = {'items' => 
+               [
+                    {
+                        'id' =>'blahblahblah', 
+                        'statistics' => {'viewCount' => '3'}, 
+                        'snippet' => {'publishedAt' => (Date.today - 30).to_s }
+                    }
+                ]
+            }
         video_json = JSON.generate(video_array)
         video_service.stub(:get_current_video_list, video_array) do
-            assert_equal(video_service.video_list, video_json)
+            video_service.stub(:get_youtube_stats_on_videos, youtube_response) do
+                result = JSON.parse(video_service.video_list)
+                actual = JSON.parse(video_json)
+                assert_equal(result[0]['youtubeID'], result[0]['youtubeID'])
+                assert_equal(result[0]['views'], result[0]['views'])
+                assert_in_delta(result[0]['monthlyViews'], result[0]['monthlyViews'], 0.1)
+            end      
         end
     end