Prevent raising validation errors for SyncDashboardsWorker

Changelog: changed

app/workers/metrics/dashboard/sync_dashboards_worker.rb

@@ -18,7 +18,7 @@ module Metrics
         dashboard_paths = ::Gitlab::Metrics::Dashboard::RepoDashboardFinder.list_dashboards(project)
 
         dashboard_paths.each do |dashboard_path|
-          ::Gitlab::Metrics::Dashboard::Importer.new(dashboard_path, project).execute!
+          ::Gitlab::Metrics::Dashboard::Importer.new(dashboard_path, project).execute
         end
       end
     end

spec/workers/metrics/dashboard/sync_dashboards_worker_spec.rb

@@ -10,16 +10,34 @@ RSpec.describe Metrics::Dashboard::SyncDashboardsWorker do
   let(:dashboard_path) { '.gitlab/dashboards/test.yml' }
 
   describe ".perform" do
-    it 'imports metrics' do
-      expect { worker.perform(project.id) }.to change(PrometheusMetric, :count).by(3)
+    context 'with valid dashboard hash' do
+      it 'imports metrics' do
+        expect { worker.perform(project.id) }.to change(PrometheusMetric, :count).by(3)
+      end
+
+      it 'is idempotent' do
+        2.times do
+          worker.perform(project.id)
+        end
+
+        expect(PrometheusMetric.count).to eq(3)
+      end
     end
 
-    it 'is idempotent' do
-      2.times do
-        worker.perform(project.id)
+    context 'with invalid dashboard hash' do
+      before do
+        allow_next_instance_of(Gitlab::Metrics::Dashboard::Importer) do |instance|
+          allow(instance).to receive(:dashboard_hash).and_return({})
+        end
       end
 
-      expect(PrometheusMetric.count).to eq(3)
+      it 'does not import metrics' do
+        expect { worker.perform(project.id) }.not_to change(PrometheusMetric, :count)
+      end
+
+      it 'does not raise an error' do
+        expect { worker.perform(project.id) }.not_to raise_error
+      end
     end
   end
 end