Add create note subscription api endpoint

test/controllers/api/note_subscriptions_controller_test.rb

@@ -0,0 +1,77 @@
+require "test_helper"
+
+module Api
+  class NoteSubscriptionsControllerTest < ActionDispatch::IntegrationTest
+    def test_routes
+      assert_routing(
+        { :path => "/api/0.6/notes/1/subscription", :method => :post },
+        { :controller => "api/note_subscriptions", :action => "create", :note_id => "1" }
+      )
+    end
+
+    def test_create
+      user = create(:user)
+      auth_header = bearer_authorization_header user
+      note = create(:note_with_comments)
+      assert_empty note.subscribers
+
+      assert_difference "NoteSubscription.count", 1 do
+        assert_difference "note.subscribers.count", 1 do
+          post api_note_subscription_path(note), :headers => auth_header
+          assert_response :success
+        end
+      end
+      assert_equal user, note.subscribers.last
+    end
+
+    def test_create_fail_anonymous
+      note = create(:note_with_comments)
+
+      assert_no_difference "NoteSubscription.count" do
+        assert_no_difference "note.subscribers.count" do
+          post api_note_subscription_path(note)
+          assert_response :unauthorized
+        end
+      end
+    end
+
+    def test_create_fail_no_scope
+      user = create(:user)
+      auth_header = bearer_authorization_header user, :scopes => %w[read_prefs]
+      note = create(:note_with_comments)
+
+      assert_no_difference "NoteSubscription.count" do
+        assert_no_difference "note.subscribers.count" do
+          post api_note_subscription_path(note), :headers => auth_header
+          assert_response :forbidden
+        end
+      end
+    end
+
+    def test_create_fail_note_not_found
+      user = create(:user)
+      auth_header = bearer_authorization_header user
+
+      assert_no_difference "NoteSubscription.count" do
+        post api_note_subscription_path(999111), :headers => auth_header
+        assert_response :not_found
+      end
+      assert_match "not found", @response.body
+    end
+
+    def test_create_fail_already_subscribed
+      user = create(:user)
+      auth_header = bearer_authorization_header user
+      note = create(:note_with_comments)
+      create(:note_subscription, :user => user, :note => note)
+
+      assert_no_difference "NoteSubscription.count" do
+        assert_no_difference "note.subscribers.count" do
+          post api_note_subscription_path(note), :headers => auth_header
+          assert_response :conflict
+        end
+      end
+      assert_match "already subscribed", @response.body
+    end
+  end
+end