Account domain blocks (#2381)

* Add <ostatus:conversation /> tag to Atom input/output

Only uses ref attribute (not href) because href would be
the alternate link that's always included also.

Creates new conversation for every non-reply status. Carries
over conversation for every reply. Keeps remote URIs verbatim,
generates local URIs on the fly like the rest of them.

* Conversation muting - prevents notifications that reference a conversation
(including replies, favourites, reblogs) from being created. API endpoints
/api/v1/statuses/:id/mute and /api/v1/statuses/:id/unmute

Currently no way to tell when a status/conversation is muted, so the web UI
only has a "disable notifications" button, doesn't work as a toggle

* Display "Dismiss notifications" on all statuses in notifications column, not just own

* Add "muted" as a boolean attribute on statuses JSON

For now always false on contained reblogs, since it's only relevant for
statuses returned from the notifications endpoint, which are not nested

Remove "Disable notifications" from detailed status view, since it's
only relevant in the notifications column

* Up max class length

* Remove pending test for conversation mute

* Add tests, clean up

* Rename to "mute conversation" and "unmute conversation"

* Raise validation error when trying to mute/unmute status without conversation

* Adding account domain blocks that filter notifications and public timelines

* Add tests for domain blocks in notifications, public timelines
Filter reblogs of blocked domains from home

* Add API for listing and creating account domain blocks

* API for creating/deleting domain blocks, tests for Status#ancestors
and Status#descendants, filter domain blocks from them

* Filter domains in streaming API

* Update account_domain_block_spec.rb

spec/models/account_domain_block_spec.rb

@@ -0,0 +1,5 @@
+require 'rails_helper'
+
+RSpec.describe AccountDomainBlock, type: :model do
+
+end

spec/models/status_spec.rb

@@ -180,8 +180,48 @@ RSpec.describe Status, type: :model do
   end
 
   describe '#ancestors' do
+    let!(:alice)  { Fabricate(:account, username: 'alice') }
+    let!(:bob)    { Fabricate(:account, username: 'bob', domain: 'example.com') }
+    let!(:jeff)   { Fabricate(:account, username: 'jeff') }
+    let!(:status) { Fabricate(:status, account: alice) }
+    let!(:reply1) { Fabricate(:status, thread: status, account: jeff) }
+    let!(:reply2) { Fabricate(:status, thread: reply1, account: bob) }
+    let!(:reply3) { Fabricate(:status, thread: reply2, account: alice) }
+    let!(:viewer) { Fabricate(:account, username: 'viewer') }
+
+    it 'returns conversation history' do
+      expect(reply3.ancestors).to include(status, reply1, reply2)
+    end
+
+    it 'does not return conversation history user is not allowed to see' do
+      reply1.update(visibility: :private)
+      status.update(visibility: :direct)
+
+      expect(reply3.ancestors(viewer)).to_not include(reply1, status)
+    end
+
+    it 'does not return conversation history from blocked users' do
+      viewer.block!(jeff)
+      expect(reply3.ancestors(viewer)).to_not include(reply1)
+    end
+
+    it 'does not return conversation history from muted users' do
+      viewer.mute!(jeff)
+      expect(reply3.ancestors(viewer)).to_not include(reply1)
+    end
+
+    it 'does not return conversation history from silenced and not followed users' do
+      jeff.update(silenced: true)
+      expect(reply3.ancestors(viewer)).to_not include(reply1)
+    end
+
+    it 'does not return conversation history from blocked domains' do
+      viewer.block_domain!('example.com')
+      expect(reply3.ancestors(viewer)).to_not include(reply2)
+    end
+
     it 'ignores deleted records' do
-      first_status = Fabricate(:status, account: bob)
+      first_status  = Fabricate(:status, account: bob)
       second_status = Fabricate(:status, thread: first_status, account: alice)
 
       # Create cache and delete cached record
@@ -192,8 +232,46 @@ RSpec.describe Status, type: :model do
     end
   end
 
-  describe '#filter_from_context?' do
-    pending
+  describe '#descendants' do
+    let!(:alice)  { Fabricate(:account, username: 'alice') }
+    let!(:bob)    { Fabricate(:account, username: 'bob', domain: 'example.com') }
+    let!(:jeff)   { Fabricate(:account, username: 'jeff') }
+    let!(:status) { Fabricate(:status, account: alice) }
+    let!(:reply1) { Fabricate(:status, thread: status, account: alice) }
+    let!(:reply2) { Fabricate(:status, thread: status, account: bob) }
+    let!(:reply3) { Fabricate(:status, thread: reply1, account: jeff) }
+    let!(:viewer) { Fabricate(:account, username: 'viewer') }
+
+    it 'returns replies' do
+      expect(status.descendants).to include(reply1, reply2, reply3)
+    end
+
+    it 'does not return replies user is not allowed to see' do
+      reply1.update(visibility: :private)
+      reply3.update(visibility: :direct)
+
+      expect(status.descendants(viewer)).to_not include(reply1, reply3)
+    end
+
+    it 'does not return replies from blocked users' do
+      viewer.block!(jeff)
+      expect(status.descendants(viewer)).to_not include(reply3)
+    end
+
+    it 'does not return replies from muted users' do
+      viewer.mute!(jeff)
+      expect(status.descendants(viewer)).to_not include(reply3)
+    end
+
+    it 'does not return replies from silenced and not followed users' do
+      jeff.update(silenced: true)
+      expect(status.descendants(viewer)).to_not include(reply3)
+    end
+
+    it 'does not return replies from blocked domains' do
+      viewer.block_domain!('example.com')
+      expect(status.descendants(viewer)).to_not include(reply2)
+    end
   end
 
   describe '.mutes_map' do
@@ -368,6 +446,15 @@ RSpec.describe Status, type: :model do
         expect(results).not_to include(muted_status)
       end
 
+      it 'excludes statuses from accounts from personally blocked domains' do
+        blocked = Fabricate(:account, domain: 'example.com')
+        @account.block_domain!(blocked.domain)
+        blocked_status = Fabricate(:status, account: blocked)
+
+        results = Status.as_public_timeline(@account)
+        expect(results).not_to include(blocked_status)
+      end
+
       context 'with language preferences' do
         it 'excludes statuses in languages not allowed by the account user' do
           user = Fabricate(:user, allowed_languages: [:en, :es])