1 files changed, 127 insertions, 0 deletions
diff --git a/spec/lib/gitlab/metrics/dashboard/processor_spec.rb b/spec/lib/gitlab/metrics/dashboard/processor_spec.rb
new file mode 100644
index 00000000000..797d4daabe3
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+++ b/spec/lib/gitlab/metrics/dashboard/processor_spec.rb
@@ -0,0 +1,127 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Metrics::Dashboard::Processor do
+  let(:project) { build(:project) }
+  let(:environment) { create(:environment, project: project) }
+  let(:dashboard_yml) { YAML.load_file('spec/fixtures/lib/gitlab/metrics/dashboard/sample_dashboard.yml') }
+
+  describe 'process' do
+    let(:process_params) { [project, environment, dashboard_yml] }
+    let(:dashboard) { described_class.new(*process_params).process(insert_project_metrics: true) }
+
+    it 'includes a path for the prometheus endpoint with each metric' do
+      expect(all_metrics).to satisfy_all do |metric|
+        metric[:prometheus_endpoint_path] == prometheus_path(metric[:query_range])
+      end
+    end
+
+    context 'when dashboard config corresponds to common metrics' do
+      let!(:common_metric) { create(:prometheus_metric, :common, identifier: 'metric_a1') }
+
+      it 'inserts metric ids into the config' do
+        target_metric = all_metrics.find { |metric| metric[:id] == 'metric_a1' }
+
+        expect(target_metric).to include(:metric_id)
+        expect(target_metric[:metric_id]).to eq(common_metric.id)
+      end
+    end
+
+    context 'when the project has associated metrics' do
+      let!(:project_response_metric) { create(:prometheus_metric, project: project, group: :response) }
+      let!(:project_system_metric) { create(:prometheus_metric, project: project, group: :system) }
+      let!(:project_business_metric) { create(:prometheus_metric, project: project, group: :business) }
+
+      it 'includes project-specific metrics' do
+        expect(all_metrics).to include get_metric_details(project_system_metric)
+        expect(all_metrics).to include get_metric_details(project_response_metric)
+        expect(all_metrics).to include get_metric_details(project_business_metric)
+      end
+
+      it 'orders groups by priority and panels by weight' do
+        expected_metrics_order = [
+          'metric_b', # group priority 10, panel weight 1
+          'metric_a2', # group priority 1, panel weight 2
+          'metric_a1', # group priority 1, panel weight 1
+          project_business_metric.id, # group priority 0, panel weight nil (0)
+          project_response_metric.id, # group priority -5, panel weight nil (0)
+          project_system_metric.id, # group priority -10, panel weight nil (0)
+        ]
+        actual_metrics_order = all_metrics.map { |m| m[:id] || m[:metric_id] }
+
+        expect(actual_metrics_order).to eq expected_metrics_order
+      end
+
+      context 'when the dashboard should not include project metrics' do
+        let(:dashboard) { described_class.new(*process_params).process(insert_project_metrics: false) }
+
+        it 'includes only dashboard metrics' do
+          metrics = all_metrics.map { |m| m[:id] }
+
+          expect(metrics.length).to be(3)
+          expect(metrics).to eq %w(metric_b metric_a2 metric_a1)
+        end
+      end
+    end
+
+    shared_examples_for 'errors with message' do |expected_message|
+      it 'raises a DashboardLayoutError' do
+        error_class = Gitlab::Metrics::Dashboard::Stages::BaseStage::DashboardProcessingError
+
+        expect { dashboard }.to raise_error(error_class, expected_message)
+      end
+    end
+
+    context 'when the dashboard is missing panel_groups' do
+      let(:dashboard_yml) { {} }
+
+      it_behaves_like 'errors with message', 'Top-level key :panel_groups must be an array'
+    end
+
+    context 'when the dashboard contains a panel_group which is missing panels' do
+      let(:dashboard_yml) { { panel_groups: [{}] } }
+
+      it_behaves_like 'errors with message', 'Each "panel_group" must define an array :panels'
+    end
+
+    context 'when the dashboard contains a panel which is missing metrics' do
+      let(:dashboard_yml) { { panel_groups: [{ panels: [{}] }] } }
+
+      it_behaves_like 'errors with message', 'Each "panel" must define an array :metrics'
+    end
+
+    context 'when the dashboard contains a metric which is missing a query' do
+      let(:dashboard_yml) { { panel_groups: [{ panels: [{ metrics: [{}] }] }] } }
+
+      it_behaves_like 'errors with message', 'Each "metric" must define one of :query or :query_range'
+    end
+  end
+
+  private
+
+  def all_metrics
+    dashboard[:panel_groups].map do |group|
+      group[:panels].map { |panel| panel[:metrics] }
+    end.flatten
+  end
+
+  def get_metric_details(metric)
+    {
+      query_range: metric.query,
+      unit: metric.unit,
+      label: metric.legend,
+      metric_id: metric.id,
+      prometheus_endpoint_path: prometheus_path(metric.query)
+    }
+  end
+
+  def prometheus_path(query)
+    Gitlab::Routing.url_helpers.prometheus_api_project_environment_path(
+      project,
+      environment,
+      proxy_path: :query_range,
+      query: query
+    )
+  end
+end