Move relationable expectations to controller tests

Having expectations related to database operations in system tests after
the process running the browser has started might result in exceptions
while running our test suite.

spec/controllers/related_contents_controller_spec.rb

@@ -10,4 +10,48 @@ describe RelatedContentsController do
       end.to raise_error ActiveRecord::RecordNotFound
     end
   end
+
+  describe "#score_positive" do
+    it "increases the score of both the related content and its opposite" do
+      user = create(:user, :level_two)
+      related_content = create(:related_content, author: create(:user))
+      opposite_content = related_content.opposite_related_content
+
+      sign_in user
+
+      put :score_positive, params: { id: related_content, format: :js }
+
+      score = related_content.related_content_scores
+                             .find_by(user: user, related_content: related_content)
+                             .value
+      opposite_score = opposite_content.related_content_scores
+                                       .find_by(user: user, related_content: opposite_content)
+                                       .value
+
+      expect(score).to eq(1)
+      expect(opposite_score).to eq(1)
+    end
+  end
+
+  describe "#score_negative" do
+    it "decreases the score of both the related content and its opposite" do
+      user = create(:user, :level_two)
+      related_content = create(:related_content, author: create(:user))
+      opposite_content = related_content.opposite_related_content
+
+      sign_in user
+
+      put :score_negative, params: { id: related_content, format: :js }
+
+      score = related_content.related_content_scores
+                             .find_by(user: user, related_content: related_content)
+                             .value
+      opposite_score = opposite_content.related_content_scores
+                                       .find_by(user: user, related_content: opposite_content)
+                                       .value
+
+      expect(score).to eq(-1)
+      expect(opposite_score).to eq(-1)
+    end
+  end
 end