1 files changed, 127 insertions, 0 deletions
diff --git a/spec/models/blob_viewer/metrics_dashboard_yml_spec.rb b/spec/models/blob_viewer/metrics_dashboard_yml_spec.rb
new file mode 100644
index 00000000000..f5b8586975d
--- /dev/null
+++ b/spec/models/blob_viewer/metrics_dashboard_yml_spec.rb
@@ -0,0 +1,127 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe BlobViewer::MetricsDashboardYml do
+  include FakeBlobHelpers
+  include RepoHelpers
+
+  let_it_be(:project) { create(:project, :repository) }
+  let(:blob) { fake_blob(path: '.gitlab/dashboards/custom-dashboard.yml', data: data) }
+  let(:sha) { sample_commit.id }
+
+  subject(:viewer) { described_class.new(blob) }
+
+  context 'when the definition is valid' do
+    let(:data) { File.read(Rails.root.join('config/prometheus/common_metrics.yml')) }
+
+    describe '#valid?' do
+      it 'calls prepare! on the viewer' do
+        allow(PerformanceMonitoring::PrometheusDashboard).to receive(:from_json)
+
+        expect(viewer).to receive(:prepare!)
+
+        viewer.valid?
+      end
+
+      it 'returns true', :aggregate_failures do
+        yml = ::Gitlab::Config::Loader::Yaml.new(data).load_raw!
+
+        expect_next_instance_of(::Gitlab::Config::Loader::Yaml, data) do |loader|
+          expect(loader).to receive(:load_raw!).and_call_original
+        end
+        expect(PerformanceMonitoring::PrometheusDashboard)
+          .to receive(:from_json)
+          .with(yml)
+          .and_call_original
+        expect(viewer.valid?).to be_truthy
+      end
+    end
+
+    describe '#errors' do
+      it 'returns nil' do
+        allow(PerformanceMonitoring::PrometheusDashboard).to receive(:from_json)
+
+        expect(viewer.errors).to be nil
+      end
+    end
+  end
+
+  context 'when definition is invalid' do
+    let(:error) { ActiveModel::ValidationError.new(PerformanceMonitoring::PrometheusDashboard.new.tap(&:validate)) }
+    let(:data) do
+      <<~YAML
+        dashboard:
+      YAML
+    end
+
+    describe '#valid?' do
+      it 'returns false' do
+        expect(PerformanceMonitoring::PrometheusDashboard)
+          .to receive(:from_json).and_raise(error)
+
+        expect(viewer.valid?).to be_falsey
+      end
+    end
+
+    describe '#errors' do
+      it 'returns validation errors' do
+        allow(PerformanceMonitoring::PrometheusDashboard)
+          .to receive(:from_json).and_raise(error)
+
+        expect(viewer.errors).to be error.model.errors
+      end
+    end
+  end
+
+  context 'when YAML syntax is invalid' do
+    let(:data) do
+      <<~YAML
+        dashboard: 'empty metrics'
+         panel_groups:
+        - group: 'Group Title'
+      YAML
+    end
+
+    describe '#valid?' do
+      it 'returns false' do
+        expect(PerformanceMonitoring::PrometheusDashboard).not_to receive(:from_json)
+        expect(viewer.valid?).to be_falsey
+      end
+    end
+
+    describe '#errors' do
+      it 'returns validation errors' do
+        yaml_wrapped_errors = { 'YAML syntax': ["(<unknown>): did not find expected key while parsing a block mapping at line 1 column 1"] }
+
+        expect(viewer.errors).to be_kind_of ActiveModel::Errors
+        expect(viewer.errors.messages).to eql(yaml_wrapped_errors)
+      end
+    end
+  end
+
+  context 'when YAML loader raises error' do
+    let(:data) do
+      <<~YAML
+        large yaml file
+      YAML
+    end
+
+    before do
+      allow(::Gitlab::Config::Loader::Yaml).to receive(:new)
+        .and_raise(::Gitlab::Config::Loader::Yaml::DataTooLargeError, 'The parsed YAML is too big')
+    end
+
+    it 'is invalid' do
+      expect(PerformanceMonitoring::PrometheusDashboard).not_to receive(:from_json)
+      expect(viewer.valid?).to be(false)
+    end
+
+    it 'returns validation errors' do
+      yaml_wrapped_errors = { 'YAML syntax': ["The parsed YAML is too big"] }
+
+      expect(viewer.errors).to be_kind_of(ActiveModel::Errors)
+      expect(viewer.errors.messages).to eq(yaml_wrapped_errors)
+    end
+  end
+end