1 files changed, 103 insertions, 0 deletions
diff --git a/spec/lib/gitlab/daemon_spec.rb b/spec/lib/gitlab/daemon_spec.rb
new file mode 100644
index 00000000000..2bdb0dfc736
--- /dev/null
+++ b/spec/lib/gitlab/daemon_spec.rb
@@ -0,0 +1,103 @@
+require 'spec_helper'
+
+describe Gitlab::Daemon do
+  subject { described_class.new }
+
+  before do
+    allow(subject).to receive(:start_working)
+    allow(subject).to receive(:stop_working)
+  end
+
+  describe '.instance' do
+    before do
+      allow(Kernel).to receive(:at_exit)
+    end
+
+    after do
+      described_class.instance_variable_set(:@instance, nil)
+    end
+
+    it 'provides instance of Daemon' do
+      expect(described_class.instance).to be_instance_of(described_class)
+    end
+
+    it 'subsequent invocations provide the same instance' do
+      expect(described_class.instance).to eq(described_class.instance)
+    end
+
+    it 'creates at_exit hook when instance is created' do
+      expect(described_class.instance).not_to be_nil
+
+      expect(Kernel).to have_received(:at_exit)
+    end
+  end
+
+  describe 'when Daemon is enabled' do
+    before do
+      allow(subject).to receive(:enabled?).and_return(true)
+    end
+
+    describe 'when Daemon is stopped' do
+      describe '#start' do
+        it 'starts the Daemon' do
+          expect { subject.start.join }.to change { subject.thread? }.from(false).to(true)
+
+          expect(subject).to have_received(:start_working)
+        end
+      end
+
+      describe '#stop' do
+        it "doesn't shutdown stopped Daemon" do
+          expect { subject.stop }.not_to change { subject.thread? }
+
+          expect(subject).not_to have_received(:start_working)
+        end
+      end
+    end
+
+    describe 'when Daemon is running' do
+      before do
+        subject.start.join
+      end
+
+      describe '#start' do
+        it "doesn't start running Daemon" do
+          expect { subject.start.join }.not_to change { subject.thread? }
+
+          expect(subject).to have_received(:start_working).once
+        end
+      end
+
+      describe '#stop' do
+        it 'shutdowns Daemon' do
+          expect { subject.stop }.to change { subject.thread? }.from(true).to(false)
+
+          expect(subject).to have_received(:stop_working)
+        end
+      end
+    end
+  end
+
+  describe 'when Daemon is disabled' do
+    before do
+      allow(subject).to receive(:enabled?).and_return(false)
+    end
+
+    describe '#start' do
+      it "doesn't start working" do
+        expect(subject.start).to be_nil
+        expect { subject.start }.not_to change { subject.thread? }
+
+        expect(subject).not_to have_received(:start_working)
+      end
+    end
+
+    describe '#stop' do
+      it "doesn't stop working" do
+        expect { subject.stop }.not_to change { subject.thread? }
+
+        expect(subject).not_to have_received(:stop_working)
+      end
+    end
+  end
+end