Cleaned up clusters_helper and cluster index haml

As we now use the same Vue app for the cluster page on all levels,
we can clean up the clusters helper and cluster index template.
It also fixes the duplicate connect cluster button.

Changelog: fixed

app/helpers/clusters_helper.rb

@@ -5,6 +5,14 @@ module ClustersHelper
     clusterable.is_a?(Project)
   end
 
+  def default_branch_name(clusterable)
+    return clusterable.default_branch if clusterable.is_a?(Project)
+  end
+
+  def clusterable_project_path(clusterable)
+    return clusterable.full_path if clusterable.is_a?(Project)
+  end
+
   def js_clusters_list_data(clusterable)
     {
       ancestor_help_path: help_page_path('user/group/clusters/index', anchor: 'cluster-precedence'),
@@ -15,24 +23,19 @@ module ClustersHelper
         gcp: { path: image_path('illustrations/logos/google_gke.svg'), text: s_('ClusterIntegration|Google GKE') }
       },
       clusters_empty_state_image: image_path('illustrations/empty-state/empty-state-clusters.svg'),
+      empty_state_image: image_path('illustrations/empty-state/empty-state-agents.svg'),
       empty_state_help_text: clusterable.empty_state_help_text,
       new_cluster_path: clusterable.new_path,
       add_cluster_path: clusterable.connect_path,
       can_add_cluster: clusterable.can_add_cluster?.to_s,
       can_admin_cluster: clusterable.can_admin_cluster?.to_s,
       display_cluster_agents: display_cluster_agents?(clusterable).to_s,
-      certificate_based_clusters_enabled: Feature.enabled?(:certificate_based_clusters, clusterable, default_enabled: :yaml, type: :ops).to_s
-    }
-  end
-
-  def js_clusters_data(clusterable)
-    {
-      default_branch_name: clusterable.default_branch,
-      empty_state_image: image_path('illustrations/empty-state/empty-state-agents.svg'),
-      project_path: clusterable.full_path,
+      certificate_based_clusters_enabled: Feature.enabled?(:certificate_based_clusters, clusterable, default_enabled: :yaml, type: :ops).to_s,
+      default_branch_name: default_branch_name(clusterable),
+      project_path: clusterable_project_path(clusterable),
       kas_address: Gitlab::Kas.external_url,
       gitlab_version: Gitlab.version_info
-    }.merge(js_clusters_list_data(clusterable))
+    }
   end
 
   def js_cluster_form_data(cluster, can_edit)

app/views/clusters/clusters/index.html.haml

@@ -4,9 +4,5 @@
 = render_gcp_signup_offer
 
 .clusters-container
-  - if display_cluster_agents?(clusterable)
-    .gl-my-6
-      .js-clusters-main-view{ data: js_clusters_data(clusterable) }
-
-  - else
+  .gl-my-6
     .js-clusters-main-view{ data: js_clusters_list_data(clusterable) }

spec/helpers/clusters_helper_spec.rb

@@ -58,6 +58,7 @@ RSpec.describe ClustersHelper do
 
     it 'displays empty image path' do
       expect(subject[:clusters_empty_state_image]).to match(%r(/illustrations/empty-state/empty-state-clusters|svg))
+      expect(subject[:empty_state_image]).to match(%r(/illustrations/empty-state/empty-state-agents|svg))
     end
 
     it 'displays create cluster using certificate path' do
@@ -68,6 +69,22 @@ RSpec.describe ClustersHelper do
       expect(subject[:add_cluster_path]).to eq("#{project_path(project)}/-/clusters/connect")
     end
 
+    it 'displays project default branch' do
+      expect(subject[:default_branch_name]).to eq(project.default_branch)
+    end
+
+    it 'displays project path' do
+      expect(subject[:project_path]).to eq(project.full_path)
+    end
+
+    it 'displays kas address' do
+      expect(subject[:kas_address]).to eq(Gitlab::Kas.external_url)
+    end
+
+    it 'displays GitLab version' do
+      expect(subject[:gitlab_version]).to eq(Gitlab.version_info)
+    end
+
     context 'user has no permissions to create a cluster' do
       it 'displays that user can\'t add cluster' do
         expect(subject[:can_add_cluster]).to eq("false")
@@ -132,34 +149,6 @@ RSpec.describe ClustersHelper do
     end
   end
 
-  describe '#js_clusters_data' do
-    let_it_be(:current_user) { create(:user) }
-    let_it_be(:project) { build(:project) }
-    let_it_be(:clusterable) { ClusterablePresenter.fabricate(project, current_user: current_user) }
-
-    subject { helper.js_clusters_data(clusterable) }
-
-    it 'displays project default branch' do
-      expect(subject[:default_branch_name]).to eq(project.default_branch)
-    end
-
-    it 'displays image path' do
-      expect(subject[:empty_state_image]).to match(%r(/illustrations/empty-state/empty-state-agents|svg))
-    end
-
-    it 'displays project path' do
-      expect(subject[:project_path]).to eq(project.full_path)
-    end
-
-    it 'displays kas address' do
-      expect(subject[:kas_address]).to eq(Gitlab::Kas.external_url)
-    end
-
-    it 'displays GitLab version' do
-      expect(subject[:gitlab_version]).to eq(Gitlab.version_info)
-    end
-  end
-
   describe '#js_cluster_new' do
     subject { helper.js_cluster_new }