Expose details of issues blocking issue

- GraphQL field causes N+1 so complexity set at 5

doc/api/graphql/reference/index.md

@@ -1767,6 +1767,7 @@ Relationship between an epic and an issue.
 | `author` | User! | User that created the issue. |
 | `blocked` | Boolean! | Indicates the issue is blocked. |
 | `blockedByCount` | Int | Count of issues blocking this issue. |
+| `blockedByIssues` | IssueConnection | Issues blocking this issue. |
 | `closedAt` | Time | Timestamp of when the issue was closed. |
 | `confidential` | Boolean! | Indicates the issue is confidential. |
 | `createNoteEmail` | String | User specific email address for the issue. |
@@ -2144,6 +2145,7 @@ A block of time for which a participant is on-call.
 | `author` | User! | User that created the issue. |
 | `blocked` | Boolean! | Indicates the issue is blocked. |
 | `blockedByCount` | Int | Count of issues blocking this issue. |
+| `blockedByIssues` | IssueConnection | Issues blocking this issue. |
 | `closedAt` | Time | Timestamp of when the issue was closed. |
 | `confidential` | Boolean! | Indicates the issue is confidential. |
 | `createNoteEmail` | String | User specific email address for the issue. |

ee/app/graphql/ee/types/issue_type.rb

@@ -21,6 +21,10 @@ module EE
         field :blocked_by_count, GraphQL::INT_TYPE, null: true,
               description: 'Count of issues blocking this issue.'
 
+        field :blocked_by_issues, ::Types::IssueType.connection_type, null: true,
+              description: 'Issues blocking this issue.',
+              complexity: 5
+
         field :health_status, ::Types::HealthStatusEnum, null: true,
               description: 'Current health status.'
 
@@ -53,6 +57,10 @@ module EE
           end
         end
 
+        def blocked_by_issues
+          object.blocked_by_issues_for(current_user)
+        end
+
         def health_status
           object.supports_health_status? ? object.health_status : nil
         end

ee/changelogs/unreleased/210452-cablett-blocking-issues-details.yml

+---
+title: Expose details of blocking issues via GraphQL
+merge_request: 54152
+author:
+type: added

ee/spec/graphql/types/issue_type_spec.rb

@@ -9,6 +9,7 @@ RSpec.describe GitlabSchema.types['Issue'] do
   it { expect(described_class).to have_graphql_field(:health_status) }
   it { expect(described_class).to have_graphql_field(:blocked) }
   it { expect(described_class).to have_graphql_field(:blocked_by_count) }
+  it { expect(described_class).to have_graphql_field(:blocked_by_issues) }
   it { expect(described_class).to have_graphql_field(:sla_due_at) }
   it { expect(described_class).to have_graphql_field(:metric_images) }
 

ee/spec/requests/api/graphql/project/issues_spec.rb

@@ -72,6 +72,9 @@ RSpec.describe 'getting an issue list for a project' do
           id
           blocked
           blockedByCount
+          blockedByIssues {
+            nodes { id }
+          }
         }
       QUERY
     end
@@ -94,16 +97,37 @@ RSpec.describe 'getting an issue list for a project' do
       post_graphql(single_issue_query, current_user: current_user)
     end
 
-    it 'returns the correct result', :aggregate_failures do
-      check_result(blocked_issue1, true, 1)
-      check_result(blocked_issue2, true, 2)
-      check_result(blocking_issue1, false, 0)
-      check_result(blocking_issue2, false, 0)
+    context 'correct result' do
+      before do
+        post_graphql(query, current_user: current_user)
       end
 
-    def check_result(issue, expected_blocked, expected_blocked_count)
-      post_graphql(query, current_user: current_user)
+      it 'returns the correct blocked count result', :aggregate_failures do
+        expect_blocked_count(blocked_issue1, true, 1)
+        expect_blocked_count(blocked_issue2, true, 2)
+        expect_blocked_count(blocking_issue1, false, 0)
+        expect_blocked_count(blocking_issue2, false, 0)
+        expect_blocked_count(blocking_issue3, false, 0)
+      end
+
+      it 'returns the correct blocked issue detail result', :aggregate_failures do
+        expect_blocking_issues(blocked_issue1, [blocking_issue1])
+        expect_blocking_issues(blocked_issue2, [blocking_issue2, blocking_issue3])
+        expect_blocking_issues(blocking_issue1, [])
+        expect_blocking_issues(blocking_issue2, [])
+        expect_blocking_issues(blocking_issue3, [])
+        expect_blocking_issues(unrelated_issue, [])
+      end
+    end
+
+    def expect_blocking_issues(issue, expected_blocking_issues)
+      nodes = graphql_data.dig('project', 'issues', 'nodes')
+      node = nodes.find { |r| r['id'] == issue.to_global_id.to_s }
+
+      expect(node['blockedByIssues']['nodes']).to match_array expected_blocking_issues.map { |i| { "id" => i.to_global_id.to_s }}
+    end
 
+    def expect_blocked_count(issue, expected_blocked, expected_blocked_count)
       nodes = graphql_data.dig('project', 'issues', 'nodes')
       node = nodes.find { |r| r['id'] == issue.to_global_id.to_s }