1 files changed, 59 insertions, 0 deletions
diff --git a/spec/models/performance_monitoring/prometheus_metric_spec.rb b/spec/models/performance_monitoring/prometheus_metric_spec.rb
new file mode 100644
index 00000000000..08288e5d993
--- /dev/null
+++ b/spec/models/performance_monitoring/prometheus_metric_spec.rb
@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe PerformanceMonitoring::PrometheusMetric do
+  let(:json_content) do
+    {
+      "id" => "metric_of_ages",
+      "unit" => "count",
+      "label" => "Metric of Ages",
+      "query_range" => "http_requests_total"
+    }
+  end
+
+  describe '.from_json' do
+    subject { described_class.from_json(json_content) }
+
+    it 'creates a PrometheusMetric object' do
+      expect(subject).to be_a PerformanceMonitoring::PrometheusMetric
+      expect(subject.id).to eq(json_content['id'])
+      expect(subject.unit).to eq(json_content['unit'])
+      expect(subject.label).to eq(json_content['label'])
+      expect(subject.query_range).to eq(json_content['query_range'])
+    end
+
+    describe 'validations' do
+      context 'when unit is missing' do
+        before do
+          json_content['unit'] = nil
+        end
+
+        subject { described_class.from_json(json_content) }
+
+        it { expect { subject }.to raise_error(ActiveModel::ValidationError) }
+      end
+
+      context 'when query and query_range is missing' do
+        before do
+          json_content['query_range'] = nil
+        end
+
+        subject { described_class.from_json(json_content) }
+
+        it { expect { subject }.to raise_error(ActiveModel::ValidationError) }
+      end
+
+      context 'when query_range is missing but query is available' do
+        before do
+          json_content['query_range'] = nil
+          json_content['query'] = 'http_requests_total'
+        end
+
+        subject { described_class.from_json(json_content) }
+
+        it { is_expected.to be_valid }
+      end
+    end
+  end
+end