Add KubernetesService#default_namespace tests

app/models/project_services/kubernetes_service.rb

@@ -155,15 +155,8 @@ class KubernetesService < DeploymentService
   def default_namespace
     return unless project
 
-    # 1. lowercase
-    # 2. replace non kubernetes characters with dash
-    # 3. trim dash from the beginning and end
-
-    slugified = "#{project.path}-#{project.id}"
-    slugified.downcase!
-    slugified.gsub!(/[^a-z0-9]/, '-')
-    slugified.gsub!(/^-+|-+$/, '')
-    slugified
+    slug = "#{project.path}-#{project.id}".downcase
+    slug.gsub(/[^-a-z0-9]/, '-').gsub(/^-+/, '')
   end
 
   def build_kubeclient!(api_path: 'api', api_version: 'v1')

spec/models/project_services/kubernetes_service_spec.rb

@@ -99,8 +99,25 @@ describe KubernetesService, :use_clean_rails_memory_store_caching do
   describe '#actual_namespace' do
     subject { service.actual_namespace }
 
-    it "returns the default namespace" do
-      is_expected.to eq(service.send(:default_namespace))
+    shared_examples 'a correctly formatted namespace' do
+      it 'returns a valid Kubernetes namespace name' do
+        expect(subject).to match(Gitlab::Regex.kubernetes_namespace_regex)
+        expect(subject).to eq(expected_namespace)
+      end
+    end
+
+    it_behaves_like 'a correctly formatted namespace' do
+      let(:expected_namespace) { service.send(:default_namespace) }
+    end
+
+    context 'when the project path contains forbidden characters' do
+      before do
+        project.path = '-a_Strange.Path--forSure'
+      end
+
+      it_behaves_like 'a correctly formatted namespace' do
+        let(:expected_namespace) { "a-strange-path--forsure-#{project.id}" }
+      end
     end
 
     context 'when namespace is specified' do
@@ -108,8 +125,8 @@ describe KubernetesService, :use_clean_rails_memory_store_caching do
         service.namespace = 'my-namespace'
       end
 
-      it "returns the user-namespace" do
-        is_expected.to eq('my-namespace')
+      it_behaves_like 'a correctly formatted namespace' do
+        let(:expected_namespace) { 'my-namespace' }
       end
     end
 
@@ -118,7 +135,7 @@ describe KubernetesService, :use_clean_rails_memory_store_caching do
         service.project = nil
       end
 
-      it "does not return namespace" do
+      it 'does not return namespace' do
         is_expected.to be_nil
       end
     end