Write test for RemoveExpiredMembersWorker.

spec/workers/remove_expired_members_worker_spec.rb

+require 'spec_helper'
+
+describe RemoveExpiredMembersWorker do
+  let!(:worker) { RemoveExpiredMembersWorker.new }
+  let!(:expired_member) { create(:project_member, expires_at: 1.hour.ago) }
+  let!(:member_expiring_in_future) { create(:project_member, expires_at: 10.days.from_now) }
+  let!(:non_expiring_member) { create(:project_member, expires_at: nil) }
+
+  describe "#perform" do
+    it "removes expired members" do
+      expect { worker.perform }.to change { Member.count }.by(-1)
+      expect(Member.find_by(id: expired_member.id)).to be_nil
+    end
+
+    it "leaves members who expire in the future" do
+      worker.perform
+      expect(member_expiring_in_future.reload).to be_present
+    end
+
+    it "leaves members who do not expire at all" do
+      worker.perform
+      expect(non_expiring_member.reload).to be_present
+    end
+  end
+end