Populate an Incident's severity when it's created from an Alert

app/services/alert_management/create_alert_issue_service.rb

@@ -41,7 +41,8 @@ module AlertManagement
         project,
         user,
         title: alert_presenter.title,
-        description: alert_presenter.issue_description
+        description: alert_presenter.issue_description,
+        severity: alert.severity
       ).execute
     end
 

app/services/incident_management/incidents/create_service.rb

@@ -5,11 +5,12 @@ module IncidentManagement
     class CreateService < BaseService
       ISSUE_TYPE = 'incident'
 
-      def initialize(project, current_user, title:, description:)
+      def initialize(project, current_user, title:, description:, severity: IssuableSeverity::DEFAULT)
         super(project, current_user)
 
         @title = title
         @description = description
+        @severity = severity
       end
 
       def execute
@@ -24,12 +25,14 @@ module IncidentManagement
 
         return error(issue.errors.full_messages.to_sentence, issue) unless issue.valid?
 
+        issue.update_severity(severity)
+
         success(issue)
       end
 
       private
 
-      attr_reader :title, :description
+      attr_reader :title, :description, :severity
 
       def find_or_create_incident_label
         IncidentManagement::CreateIncidentLabelService

changelogs/unreleased/238571-populate-severity-for-incident-created-from-alert.yml

+---
+title: Set incident severity when it is created from an alert.
+merge_request: 42072
+author:
+type: added

spec/services/alert_management/create_alert_issue_service_spec.rb

@@ -82,6 +82,30 @@ RSpec.describe AlertManagement::CreateAlertIssueService do
         expect(user).to have_received(:can?).with(:create_issue, project)
       end
 
+      context 'with alert severity' do
+        using RSpec::Parameterized::TableSyntax
+
+        where(:alert_severity, :incident_severity) do
+          'critical' | 'critical'
+          'high'     | 'high'
+          'medium'   | 'medium'
+          'low'      | 'low'
+          'info'     | 'unknown'
+          'unknown'  | 'unknown'
+        end
+
+        with_them do
+          before do
+            alert.update!(severity: alert_severity)
+            execute
+          end
+
+          it 'sets the correct severity level' do
+            expect(created_issue.severity).to eq(incident_severity)
+          end
+        end
+      end
+
       context 'when the alert is prometheus alert' do
         let(:alert) { prometheus_alert }
         let(:issue) { subject.payload[:issue] }

spec/services/incident_management/incidents/create_service_spec.rb

@@ -34,6 +34,34 @@ RSpec.describe IncidentManagement::Incidents::CreateService do
         end
       end
 
+      context 'with default severity' do
+        it 'sets the correct severity level to "unknown"' do
+          create_incident
+          expect(new_issue.severity).to eq(IssuableSeverity::DEFAULT)
+        end
+      end
+
+      context 'with severity' do
+        using RSpec::Parameterized::TableSyntax
+
+        subject(:create_incident) { described_class.new(project, user, title: title, description: description, severity: severity).execute }
+
+        where(:severity, :incident_severity) do
+          'critical' | 'critical'
+          'high'     | 'high'
+          'medium'   | 'medium'
+          'low'      | 'low'
+          'unknown'  | 'unknown'
+        end
+
+        with_them do
+          it 'sets the correct severity level' do
+            create_incident
+            expect(new_issue.severity).to eq(incident_severity)
+          end
+        end
+      end
+
       context 'when incident label does not exists' do
         it 'creates incident label' do
           expect { create_incident }.to change { project.labels.where(title: label_title).count }.by(1)