Add validations to DevOpsReport::Metric

This commit:

- Adds presence and numericality validations to DevOpsReport::Metric
model to not rely on database constraints alone when handling record
creation.

- Moves the `METRICS` constant to the model to have a single source of
truth for these metric attributes.

app/models/dev_ops_report/metric.rb

@@ -6,6 +6,20 @@ module DevOpsReport
 
     self.table_name = 'conversational_development_index_metrics'
 
+    METRICS = %w[leader_issues instance_issues percentage_issues leader_notes instance_notes
+                 percentage_notes leader_milestones instance_milestones percentage_milestones
+                 leader_boards instance_boards percentage_boards leader_merge_requests
+                 instance_merge_requests percentage_merge_requests leader_ci_pipelines
+                 instance_ci_pipelines percentage_ci_pipelines leader_environments instance_environments
+                 percentage_environments leader_deployments instance_deployments percentage_deployments
+                 leader_projects_prometheus_active instance_projects_prometheus_active
+                 percentage_projects_prometheus_active leader_service_desk_issues instance_service_desk_issues
+                 percentage_service_desk_issues].freeze
+
+    METRICS.each do |metric_name|
+      validates metric_name, presence: true, numericality: { greater_than_or_equal_to: 0 }
+    end
+
     def instance_score(feature)
       self["instance_#{feature}"]
     end

app/services/service_ping/devops_report_service.rb

@@ -2,16 +2,6 @@
 
 module ServicePing
   class DevopsReportService
-    METRICS = %w[leader_issues instance_issues percentage_issues leader_notes instance_notes
-                 percentage_notes leader_milestones instance_milestones percentage_milestones
-                 leader_boards instance_boards percentage_boards leader_merge_requests
-                 instance_merge_requests percentage_merge_requests leader_ci_pipelines
-                 instance_ci_pipelines percentage_ci_pipelines leader_environments instance_environments
-                 percentage_environments leader_deployments instance_deployments percentage_deployments
-                 leader_projects_prometheus_active instance_projects_prometheus_active
-                 percentage_projects_prometheus_active leader_service_desk_issues instance_service_desk_issues
-                 percentage_service_desk_issues].freeze
-
     def initialize(data)
       @data = data
     end
@@ -22,7 +12,7 @@ module ServicePing
       return unless metrics.except('usage_data_id').present?
 
       DevOpsReport::Metric.create!(
-        metrics.slice(*METRICS)
+        metrics.slice(*DevOpsReport::Metric::METRICS)
       )
     end
   end

spec/models/dev_ops_report/metric_spec.rb

@@ -5,6 +5,13 @@ require 'spec_helper'
 RSpec.describe DevOpsReport::Metric do
   let(:conv_dev_index) { create(:dev_ops_report_metric) }
 
+  describe 'validations' do
+    DevOpsReport::Metric::METRICS.each do |metric_name|
+      it { is_expected.to validate_presence_of(metric_name) }
+      it { is_expected.to validate_numericality_of(metric_name).is_greater_than_or_equal_to(0) }
+    end
+  end
+
   describe '#percentage_score' do
     it 'returns stored percentage score' do
       expect(conv_dev_index.percentage_score('issues')).to eq(13.331)