Move non-controller code into dedicated service

This should help with code re-use when we create applications for group
level cluster next.

Change `find_or_initialize_by` to explicitly find or build the right
association based on the application name. The benefit here is that we
use the associations on @cluster rather than querying from the other
side of the association.

1 files changed, 63 insertions, 0 deletions

diff --git a/spec/services/clusters/applications/create_service_spec.rb b/spec/services/clusters/applications/create_service_spec.rb
new file mode 100644
index 00000000000..58d9682602a
--- /dev/null
+++ b/spec/services/clusters/applications/create_service_spec.rb
@@ -0,0 +1,63 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Clusters::Applications::CreateService do
+  let(:cluster) { create(:cluster) }
+  let(:user) { create(:user) }
+  let(:params) { { application: 'helm' } }
+  let(:service) { described_class.new(cluster, user, params) }
+
+  let(:request) do
+    if Gitlab.rails5?
+      ActionController::TestRequest.new({ remote_ip: "127.0.0.1" }, ActionController::TestSession.new)
+    else
+      ActionController::TestRequest.new(remote_ip: "127.0.0.1")
+    end
+  end
+
+  describe '#execute' do
+    subject { service.execute(request) }
+
+    it 'creates an application' do
+      expect do
+        subject
+
+        cluster.reload
+      end.to change(cluster, :application_helm)
+    end
+
+    context 'jupyter application' do
+      let(:params) do
+        {
+          application: 'jupyter',
+          hostname: 'example.com'
+        }
+      end
+
+      it 'creates the application' do
+        expect do
+          subject
+
+          cluster.reload
+        end.to change(cluster, :application_jupyter)
+      end
+
+      it 'sets the hostname' do
+        expect(subject.hostname).to eq('example.com')
+      end
+
+      it 'sets the oauth_application' do
+        expect(subject.oauth_application).to be_present
+      end
+    end
+
+    context 'invalid application' do
+      let(:params) { { application: 'non-existent' } }
+
+      it 'raises an error' do
+        expect { subject }.to raise_error(Clusters::Applications::CreateService::InvalidApplicationError)
+      end
+    end
+  end
+end