1 files changed, 134 insertions, 0 deletions
diff --git a/spec/lib/gitlab/prometheus/queries/matched_metric_query_spec.rb b/spec/lib/gitlab/prometheus/queries/matched_metric_query_spec.rb
new file mode 100644
index 00000000000..420218a695a
--- /dev/null
+++ b/spec/lib/gitlab/prometheus/queries/matched_metric_query_spec.rb
@@ -0,0 +1,134 @@
+require 'spec_helper'
+
+describe Gitlab::Prometheus::Queries::MatchedMetricQuery do
+  include Prometheus::MetricBuilders
+
+  let(:metric_group_class) { Gitlab::Prometheus::MetricGroup }
+  let(:metric_class) { Gitlab::Prometheus::Metric }
+
+  def series_info_with_environment(*more_metrics)
+    %w{metric_a metric_b}.concat(more_metrics).map { |metric_name| { '__name__' => metric_name, 'environment' => '' } }
+  end
+
+  let(:metric_names) { %w{metric_a metric_b} }
+  let(:series_info_without_environment) do
+    [{ '__name__' => 'metric_a' },
+     { '__name__' => 'metric_b' }]
+  end
+  let(:partialy_empty_series_info) { [{ '__name__' => 'metric_a', 'environment' => '' }] }
+  let(:empty_series_info) { [] }
+
+  let(:client) { double('prometheus_client') }
+
+  subject { described_class.new(client) }
+
+  context 'with one group where two metrics is found' do
+    before do
+      allow(metric_group_class).to receive(:common_metrics).and_return([simple_metric_group])
+      allow(client).to receive(:label_values).and_return(metric_names)
+    end
+
+    context 'both metrics in the group pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_with_environment)
+      end
+
+      it 'responds with both metrics as actve' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 2, metrics_missing_requirements: 0 }])
+      end
+    end
+
+    context 'none of the metrics pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_without_environment)
+      end
+
+      it 'responds with both metrics missing requirements' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 0, metrics_missing_requirements: 2 }])
+      end
+    end
+
+    context 'no series information found about the metrics' do
+      before do
+        allow(client).to receive(:series).and_return(empty_series_info)
+      end
+
+      it 'responds with both metrics missing requirements' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 0, metrics_missing_requirements: 2 }])
+      end
+    end
+
+    context 'one of the series info was not found' do
+      before do
+        allow(client).to receive(:series).and_return(partialy_empty_series_info)
+      end
+      it 'responds with one active and one missing metric' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 1, metrics_missing_requirements: 1 }])
+      end
+    end
+  end
+
+  context 'with one group where only one metric is found' do
+    before do
+      allow(metric_group_class).to receive(:common_metrics).and_return([simple_metric_group])
+      allow(client).to receive(:label_values).and_return('metric_a')
+    end
+
+    context 'both metrics in the group pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_with_environment)
+      end
+
+      it 'responds with one metrics as active and no missing requiremens' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 1, metrics_missing_requirements: 0 }])
+      end
+    end
+
+    context 'no metrics in group pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_without_environment)
+      end
+
+      it 'responds with one metrics as active and no missing requiremens' do
+        expect(subject.query).to eq([{ group: 'name', priority: 1, active_metrics: 0, metrics_missing_requirements: 1 }])
+      end
+    end
+  end
+
+  context 'with two groups where metrics are found in each group' do
+    let(:second_metric_group) { simple_metric_group(name: 'nameb', metrics: simple_metrics(added_metric_name: 'metric_c')) }
+
+    before do
+      allow(metric_group_class).to receive(:common_metrics).and_return([simple_metric_group, second_metric_group])
+      allow(client).to receive(:label_values).and_return('metric_c')
+    end
+
+    context 'all metrics in both groups pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_with_environment('metric_c'))
+      end
+
+      it 'responds with one metrics as active and no missing requiremens' do
+        expect(subject.query).to eq([
+                                      { group: 'name', priority: 1, active_metrics: 1, metrics_missing_requirements: 0 },
+                                      { group: 'nameb', priority: 1, active_metrics: 2, metrics_missing_requirements: 0 }
+                                    ]
+                                   )
+      end
+    end
+
+    context 'no metrics in groups pass requirements' do
+      before do
+        allow(client).to receive(:series).and_return(series_info_without_environment)
+      end
+
+      it 'responds with one metrics as active and no missing requiremens' do
+        expect(subject.query).to eq([
+                                      { group: 'name', priority: 1, active_metrics: 0, metrics_missing_requirements: 1 },
+                                      { group: 'nameb', priority: 1, active_metrics: 0, metrics_missing_requirements: 2 }
+                                    ]
+                                   )
+      end
+    end
+  end
+end