Fix loading Home TL from database not respecting min_id and not including DMs (#1744)

* Rework tests

* Add tests

* Fix HomeFeed#get with min_id fetching from database

* Minor code cleanup and optimizations

* Add tests

* Take DMs into account when fetching home TL from database

* Fix not listing own DMs in Home timeline

* Add tests

* Please CodeClimate

spec/models/home_feed_spec.rb

@@ -1,33 +1,83 @@
 require 'rails_helper'
 
 RSpec.describe HomeFeed, type: :model do
-  let(:account) { Fabricate(:account) }
+  let(:account)  { Fabricate(:account) }
+  let(:followed) { Fabricate(:account) }
+  let(:other)    { Fabricate(:account) }
 
   subject { described_class.new(account) }
 
   describe '#get' do
     before do
-      Fabricate(:status, account: account, id: 1)
-      Fabricate(:status, account: account, id: 2)
-      Fabricate(:status, account: account, id: 3)
-      Fabricate(:status, account: account, id: 10)
+      account.follow!(followed)
+
+      Fabricate(:status, account: account,  id: 1)
+      Fabricate(:status, account: account,  id: 2)
+      status = Fabricate(:status, account: followed, id: 3)
+      Fabricate(:mention, account: account, status: status)
+      Fabricate(:status, account: account,  id: 10)
+      Fabricate(:status, account: other,    id: 11)
+      Fabricate(:status, account: followed, id: 12, visibility: :private)
+      Fabricate(:status, account: followed, id: 13, visibility: :direct)
+      Fabricate(:status, account: account,  id: 14, visibility: :direct)
+      dm = Fabricate(:status, account: followed, id: 15, visibility: :direct)
+      Fabricate(:mention, account: account, status: dm)
     end
 
     context 'when feed is generated' do
       before do
+        FeedManager.instance.populate_home(account)
+
+        # Add direct messages because populate_home does not do that
         Redis.current.zadd(
           FeedManager.instance.key(:home, account.id),
-          [[4, 4], [3, 3], [2, 2], [1, 1]]
+          [[14, 14], [15, 15]]
         )
       end
 
       it 'gets statuses with ids in the range from redis with database' do
-        results = subject.get(3)
+        results = subject.get(5)
 
-        expect(results.map(&:id)).to eq [3, 2, 1]
+        expect(results.map(&:id)).to eq [15, 14, 12, 10, 3]
         expect(results.first.attributes.keys).to eq %w(id updated_at)
       end
 
+      it 'with since_id present' do
+        results = subject.get(5, nil, 3, nil)
+        expect(results.map(&:id)).to eq [15, 14, 12, 10]
+      end
+
+      it 'with min_id present' do
+        results = subject.get(3, nil, nil, 0)
+        expect(results.map(&:id)).to eq [3, 2, 1]
+      end
+    end
+
+    context 'when feed is only partial' do
+      before do
+        FeedManager.instance.populate_home(account)
+
+        # Add direct messages because populate_home does not do that
+        Redis.current.zadd(
+          FeedManager.instance.key(:home, account.id),
+          [[14, 14], [15, 15]]
+        )
+
+        Redis.current.zremrangebyrank(FeedManager.instance.key(:home, account.id), 0, -2)
+      end
+
+      it 'gets statuses with ids in the range from redis with database' do
+        results = subject.get(5)
+
+        expect(results.map(&:id)).to eq [15, 14, 12, 10, 3]
+        expect(results.first.attributes.keys).to eq %w(id updated_at)
+      end
+
+      it 'with since_id present' do
+        results = subject.get(5, nil, 3, nil)
+        expect(results.map(&:id)).to eq [15, 14, 12, 10]
+      end
+
       it 'with min_id present' do
         results = subject.get(3, nil, nil, 0)
         expect(results.map(&:id)).to eq [3, 2, 1]
@@ -40,9 +90,14 @@ RSpec.describe HomeFeed, type: :model do
       end
 
       it 'returns from database' do
-        results = subject.get(3)
+        results = subject.get(5)
 
-        expect(results.map(&:id)).to eq [10, 3, 2]
+        expect(results.map(&:id)).to eq [15, 14, 12, 10, 3]
+      end
+
+      it 'with since_id present' do
+        results = subject.get(5, nil, 3, nil)
+        expect(results.map(&:id)).to eq [15, 14, 12, 10]
       end
 
       it 'with min_id present' do