Simplify testing records exclusion

When we already have tests checking which records are included, in the
tests testing records are not included we can just generate records
which will not be included and test against an empty array.

We were already using this approach in some tests. This way we also
avoid useless assignments.

spec/models/debate_spec.rb

@@ -748,7 +748,7 @@ describe Debate do
       expect(Debate.recommendations(user)).to be_empty
     end
 
-    it "returns debates ordered by cached_votes_total" do
+    it "returns debates related to the user's interests ordered by cached_votes_total" do
       debate1 =  create(:debate, cached_votes_total: 1, tag_list: "Sport")
       debate2 =  create(:debate, cached_votes_total: 5, tag_list: "Sport")
       debate3 =  create(:debate, cached_votes_total: 10, tag_list: "Sport")
@@ -760,26 +760,24 @@ describe Debate do
       expect(results).to eq [debate3, debate2, debate1]
     end
 
-    it "returns debates related with user interests" do
-      debate1 =  create(:debate, tag_list: "Sport")
-      debate2 =  create(:debate, tag_list: "Politics")
+    it "does not return debates unrelated to user interests" do
       proposal1 = create(:proposal, tag_list: "Sport")
       create(:follow, followable: proposal1, user: user)
+      debate2 =  create(:debate, tag_list: "Politics")
 
-      result = Debate.recommendations(user)
+      results = Debate.recommendations(user)
 
-      expect(result).to eq [debate1]
+      expect(results).to be_empty
     end
 
     it "does not return debates when user is the author" do
-      debate1 =  create(:debate, author: user, tag_list: "Sport")
-      debate2 =  create(:debate, tag_list: "Sport")
       proposal = create(:proposal, tag_list: "Sport")
       create(:follow, followable: proposal, user: user)
+      debate1 =  create(:debate, author: user, tag_list: "Sport")
 
-      result = Debate.recommendations(user)
+      results = Debate.recommendations(user)
 
-      expect(result).to eq [debate2]
+      expect(results).to be_empty
     end
 
   end

spec/models/proposal_spec.rb

@@ -962,7 +962,7 @@ describe Proposal do
       expect(Proposal.recommendations(user)).to be_empty
     end
 
-    it "returns proposals ordered by cached_votes_up" do
+    it "returns proposals related to the user's interests ordered by cached_votes_up" do
       proposal1 = create(:proposal, cached_votes_up: 1,  tag_list: "Sport")
       proposal2 = create(:proposal, cached_votes_up: 5,  tag_list: "Sport")
       proposal3 = create(:proposal, cached_votes_up: 10, tag_list: "Sport")
@@ -974,58 +974,54 @@ describe Proposal do
       expect(results).to eq [proposal3, proposal2, proposal1]
     end
 
-    it "returns proposals related with user interests" do
+    it "does not return proposals unrelated to user interests" do
       proposal1 =  create(:proposal, tag_list: "Sport")
-      proposal2 =  create(:proposal, tag_list: "Sport")
-      proposal3 =  create(:proposal, tag_list: "Politics")
+      proposal2 = create(:proposal, tag_list: "Politics")
       create(:follow, followable: proposal1, user: user)
 
-      result = Proposal.recommendations(user)
+      results = Proposal.recommendations(user)
 
-      expect(result).to eq [proposal2]
+      expect(results).to be_empty
     end
 
     it "does not return proposals when user is follower" do
       proposal1 = create(:proposal, tag_list: "Sport")
       create(:follow, followable: proposal1, user: user)
 
-      result = Proposal.recommendations(user)
+      results = Proposal.recommendations(user)
 
-      expect(result).to be_empty
+      expect(results).to be_empty
     end
 
     it "does not return proposals when user is the author" do
-      proposal1 =  create(:proposal, author: user, tag_list: "Sport")
-      proposal2 =  create(:proposal, tag_list: "Sport")
-      proposal3 =  create(:proposal, tag_list: "Sport")
-      create(:follow, followable: proposal3, user: user)
+      proposal1 = create(:proposal, tag_list: "Sport")
+      proposal2 = create(:proposal, author: user, tag_list: "Sport")
+      create(:follow, followable: proposal1, user: user)
 
-      result = Proposal.recommendations(user)
+      results = Proposal.recommendations(user)
 
-      expect(result).to eq [proposal2]
+      expect(results).to be_empty
     end
 
     it "does not return archived proposals" do
       proposal1 = create(:proposal, tag_list: "Sport")
-      proposal2 = create(:proposal, tag_list: "Sport")
       archived_proposal = create(:proposal, :archived, tag_list: "Sport")
       create(:follow, followable: proposal1, user: user)
 
-      result = Proposal.recommendations(user)
+      results = Proposal.recommendations(user)
 
-      expect(result).to eq([proposal2])
+      expect(results).to be_empty
     end
 
     it "does not return already supported proposals" do
       proposal1 = create(:proposal, tag_list: "Health")
       proposal2 = create(:proposal, tag_list: "Health")
-      proposal3 = create(:proposal, tag_list: "Health")
       create(:vote, votable: proposal1, voter: user)
       create(:follow, followable: proposal2, user: user)
 
-      result = Proposal.recommendations(user)
+      results = Proposal.recommendations(user)
 
-      expect(result).to eq([proposal3])
+      expect(results).to be_empty
     end
 
   end