Add health status data to the graphQL endpoint

- calculate epic health status based on issues

doc/api/graphql/reference/gitlab_schema.graphql

@@ -2023,6 +2023,11 @@ type Epic implements Noteable {
   """
   hasIssues: Boolean!
 
+  """
+  Current health status of the epic
+  """
+  healthStatus: EpicHealthStatus
+
   """
   ID of the epic
   """
@@ -2294,6 +2299,26 @@ type EpicEdge {
   node: Epic
 }
 
+"""
+Health status of child issues
+"""
+type EpicHealthStatus {
+  """
+  Number of issues at risk
+  """
+  issuesAtRisk: Int
+
+  """
+  Number of issues that need attention
+  """
+  issuesNeedingAttention: Int
+
+  """
+  Number of issues on track
+  """
+  issuesOnTrack: Int
+}
+
 """
 Relationship between an epic and an issue
 """

doc/api/graphql/reference/gitlab_schema.json

@@ -5186,6 +5186,20 @@
               "isDeprecated": false,
               "deprecationReason": null
             },
+            {
+              "name": "healthStatus",
+              "description": "Current health status of the epic",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "EpicHealthStatus",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "id",
               "description": "ID of the epic",
@@ -13084,6 +13098,61 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "OBJECT",
+          "name": "EpicHealthStatus",
+          "description": "Health status of child issues",
+          "fields": [
+            {
+              "name": "issuesAtRisk",
+              "description": "Number of issues at risk",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "Int",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "issuesNeedingAttention",
+              "description": "Number of issues that need attention",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "Int",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "issuesOnTrack",
+              "description": "Number of issues on track",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "Int",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "OBJECT",
           "name": "TimelogConnection",

doc/api/graphql/reference/index.md

@@ -327,6 +327,7 @@ Represents an epic.
 | `group` | Group! | Group to which the epic belongs |
 | `hasChildren` | Boolean! | Indicates if the epic has children |
 | `hasIssues` | Boolean! | Indicates if the epic has direct issues |
+| `healthStatus` | EpicHealthStatus | Current health status of the epic |
 | `id` | ID! | ID of the epic |
 | `iid` | ID! | Internal ID of the epic |
 | `parent` | Epic | Parent epic of the epic |
@@ -366,6 +367,16 @@ Total weight of open and closed descendant issues
 | `closedIssues` | Int | Total weight of completed (closed) issues in this epic, including epic descendants |
 | `openedIssues` | Int | Total weight of opened issues in this epic, including epic descendants |
 
+## EpicHealthStatus
+
+Health status of child issues
+
+| Name  | Type  | Description |
+| ---   |  ---- | ----------  |
+| `issuesAtRisk` | Int | Number of issues at risk |
+| `issuesNeedingAttention` | Int | Number of issues that need attention |
+| `issuesOnTrack` | Int | Number of issues on track |
+
 ## EpicIssue
 
 Relationship between an epic and an issue

ee/app/graphql/types/epic_health_status_type.rb

+# frozen_string_literal: true
+
+module Types
+  # rubocop: disable Graphql/AuthorizeTypes
+  class EpicHealthStatusType < BaseObject
+    graphql_name 'EpicHealthStatus'
+    description 'Health status of child issues'
+
+    field :issues_on_track, GraphQL::INT_TYPE, null: true, description: 'Number of issues on track'
+    field :issues_needing_attention, GraphQL::INT_TYPE, null: true, description: 'Number of issues that need attention'
+    field :issues_at_risk, GraphQL::INT_TYPE, null: true, description: 'Number of issues at risk'
+  end
+  # rubocop: enable Graphql/AuthorizeTypes
+end

ee/app/graphql/types/epic_type.rb

@@ -138,5 +138,11 @@ module Types
       resolve: -> (epic, args, ctx) do
         Gitlab::Graphql::Aggregations::Epics::LazyEpicAggregate.new(ctx, epic.id, WEIGHT_SUM)
       end
+
+    field :health_status, Types::EpicHealthStatusType, null: true, complexity: 10,
+      description: 'Current health status of the epic',
+      resolve: -> (epic, args, ctx) do
+        Epics::DescendantCountService.new(epic, ctx[:current_user])
+      end
   end
 end

ee/app/models/ee/issue.rb

@@ -26,6 +26,7 @@ module EE
         issue_ids = EpicIssue.where(epic_id: epics).select(:issue_id)
         id_in(issue_ids)
       end
+      scope :counts_by_health_status, -> { reorder(nil).group(:health_status).count }
 
       has_one :epic_issue
       has_one :epic, through: :epic_issue

ee/app/services/epics/descendant_count_service.rb

@@ -31,6 +31,18 @@ module Epics
       issues_count.fetch(closed_state_id, 0)
     end
 
+    def issues_on_track
+      issue_health_statuses.fetch('on_track', 0)
+    end
+
+    def issues_needing_attention
+      issue_health_statuses.fetch('needs_attention', 0)
+    end
+
+    def issues_at_risk
+      issue_health_statuses.fetch('at_risk', 0)
+    end
+
     private
 
     def epics_count
@@ -45,6 +57,12 @@ module Epics
       end
     end
 
+    def issue_health_statuses
+      strong_memoize(:issue_health_statuses) do
+        Issue.in_epics(accessible_epics).counts_by_health_status
+      end
+    end
+
     def accessible_epics
       strong_memoize(:epics) do
         epic.base_and_descendants

ee/changelogs/unreleased/199184-health-status-display.yml

+---
+title: Add health status data to the epic GraphQL endpoint
+merge_request: 25989
+author:
+type: added

ee/spec/graphql/types/epic_type_spec.rb

@@ -11,7 +11,7 @@ describe GitlabSchema.types['Epic'] do
       closed_at created_at updated_at children has_children has_issues
       web_path web_url relation_path reference issues user_permissions
       notes discussions relative_position subscribed participants
-      descendant_counts descendant_weight_sum upvotes downvotes
+      descendant_counts descendant_weight_sum upvotes downvotes health_status
     ]
   end
 

ee/spec/models/issue_spec.rb

@@ -67,6 +67,16 @@ describe Issue do
       end
     end
 
+    describe '.counts_by_health_status' do
+      it 'returns counts grouped by health_status' do
+        create(:issue, health_status: :on_track)
+        create(:issue, health_status: :on_track)
+        create(:issue, health_status: :at_risk)
+
+        expect(Issue.counts_by_health_status).to eq({ 'on_track' => 2, 'at_risk' => 1 } )
+      end
+    end
+
     context 'epics' do
       let_it_be(:epic1) { create(:epic) }
       let_it_be(:epic2) { create(:epic) }

ee/spec/services/epics/descendant_count_service_spec.rb

@@ -11,12 +11,13 @@ describe Epics::DescendantCountService do
   let_it_be(:epic2) { create(:epic, group: subgroup, parent: parent_epic, state: :closed) }
 
   let_it_be(:project) { create(:project, :private, group: group)}
-  let_it_be(:issue1) { create(:issue, project: project, state: :opened) }
-  let_it_be(:issue2) { create(:issue, project: project, state: :closed) }
+  let_it_be(:issue1) { create(:issue, project: project, state: :opened, health_status: :on_track) }
+  let_it_be(:issue2) { create(:issue, project: project, state: :closed, health_status: :on_track) }
   let_it_be(:issue3) { create(:issue, project: project, state: :opened) }
-  let_it_be(:issue4) { create(:issue, project: project, state: :closed) }
-  let_it_be(:issue5) { create(:issue, :confidential, project: project, state: :opened) }
-  let_it_be(:issue6) { create(:issue, :confidential, project: project, state: :closed) }
+  let_it_be(:issue4) { create(:issue, project: project, state: :closed, health_status: :needs_attention) }
+  let_it_be(:issue5) { create(:issue, :confidential, project: project, state: :opened, health_status: :at_risk) }
+  let_it_be(:issue6) { create(:issue, :confidential, project: project, state: :closed, health_status: :at_risk) }
+
   let_it_be(:epic_issue1) { create(:epic_issue, epic: parent_epic, issue: issue1) }
   let_it_be(:epic_issue2) { create(:epic_issue, epic: parent_epic, issue: issue2) }
   let_it_be(:epic_issue3) { create(:epic_issue, epic: epic1, issue: issue3) }
@@ -51,4 +52,16 @@ describe Epics::DescendantCountService do
   describe '#closed_issues' do
     it_behaves_like 'descendants state count', :closed_issues, 3
   end
+
+  describe '#issues_on_track' do
+    it_behaves_like 'descendants state count', :issues_on_track, 2
+  end
+
+  describe '#issues_needing_attention' do
+    it_behaves_like 'descendants state count', :issues_needing_attention, 1
+  end
+
+  describe '#issues_at_risk' do
+    it_behaves_like 'descendants state count', :issues_at_risk, 2
+  end
 end