Extract authorization policy for viewing statuses (#3150)

spec/policies/status_policy_spec.rb

@@ -0,0 +1,70 @@
+require 'rails_helper'
+require 'pundit/rspec'
+
+RSpec.describe StatusPolicy, type: :model do
+  subject { described_class }
+
+  let(:alice) { Fabricate(:account, username: 'alice') }
+  let(:status) { Fabricate(:status, account: alice) }
+
+  permissions :show? do
+    it 'grants access when direct and account is viewer' do
+      status.visibility = :direct
+      expect(subject).to permit(status.account, status)
+    end
+
+    it 'grants access when direct and viewer is mentioned' do
+      status.visibility = :direct
+      status.mentions = [Fabricate(:mention, account: alice)]
+
+      expect(subject).to permit(alice, status)
+    end
+
+    it 'denies access when direct and viewer is not mentioned' do
+      viewer = Fabricate(:account)
+      status.visibility = :direct
+
+      expect(subject).to_not permit(viewer, status)
+    end
+
+    it 'grants access when private and account is viewer' do
+      status.visibility = :direct
+
+      expect(subject).to permit(status.account, status)
+    end
+
+    it 'grants access when private and account is following viewer' do
+      follow = Fabricate(:follow)
+      status.visibility = :private
+      status.account = follow.target_account
+
+      expect(subject).to permit(follow.account, status)
+    end
+
+    it 'grants access when private and viewer is mentioned' do
+      status.visibility = :private
+      status.mentions = [Fabricate(:mention, account: alice)]
+
+      expect(subject).to permit(alice, status)
+    end
+
+    it 'denies access when private and viewer is not mentioned or followed' do
+      viewer = Fabricate(:account)
+      status.visibility = :private
+
+      expect(subject).to_not permit(viewer, status)
+    end
+
+    it 'grants access when no viewer' do
+      expect(subject).to permit(nil, status)
+    end
+
+    it 'denies access when viewer is blocked' do
+      block = Fabricate(:block)
+      status.visibility = :private
+      status.account = block.target_account
+
+      expect(subject).to_not permit(block.account, status)
+    end
+  end
+end