1 files changed, 65 insertions, 0 deletions
diff --git a/spec/initializers/diagnostic_reports_spec.rb b/spec/initializers/diagnostic_reports_spec.rb
new file mode 100644
index 00000000000..70574194916
--- /dev/null
+++ b/spec/initializers/diagnostic_reports_spec.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'diagnostic reports' do
+  subject(:load_initializer) do
+    load Rails.root.join('config/initializers/diagnostic_reports.rb')
+  end
+
+  shared_examples 'does not modify worker startup hooks' do
+    it do
+      expect(Gitlab::Cluster::LifecycleEvents).not_to receive(:on_worker_start)
+      expect(Gitlab::Memory::ReportsDaemon).not_to receive(:instance)
+
+      load_initializer
+    end
+  end
+
+  context 'when GITLAB_DIAGNOSTIC_REPORTS_ENABLED is set to true' do
+    before do
+      stub_env('GITLAB_DIAGNOSTIC_REPORTS_ENABLED', true)
+    end
+
+    context 'when run in application context' do
+      before do
+        allow(::Gitlab::Runtime).to receive(:application?).and_return(true)
+      end
+
+      it 'modifies worker startup hooks' do
+        report_daemon = instance_double(Gitlab::Memory::ReportsDaemon)
+
+        expect(Gitlab::Cluster::LifecycleEvents).to receive(:on_worker_start).and_call_original
+        expect(Gitlab::Memory::ReportsDaemon).to receive(:instance).and_return(report_daemon)
+        expect(report_daemon).to receive(:start)
+
+        load_initializer
+      end
+    end
+
+    context 'when run in non-application context, such as rails console or tests' do
+      before do
+        allow(::Gitlab::Runtime).to receive(:application?).and_return(false)
+      end
+
+      include_examples 'does not modify worker startup hooks'
+    end
+  end
+
+  context 'when GITLAB_DIAGNOSTIC_REPORTS_ENABLED is not set' do
+    before do
+      allow(::Gitlab::Runtime).to receive(:application?).and_return(true)
+    end
+
+    include_examples 'does not modify worker startup hooks'
+  end
+
+  context 'when GITLAB_DIAGNOSTIC_REPORTS_ENABLED is set to false' do
+    before do
+      stub_env('GITLAB_DIAGNOSTIC_REPORTS_ENABLED', false)
+      allow(::Gitlab::Runtime).to receive(:application?).and_return(true)
+    end
+
+    include_examples 'does not modify worker startup hooks'
+  end
+end