Merge branch 'graphql-issue-related-merge-requests' into 'master'

Add Issue.relatedMergeRequests to GraphQL API

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/107804



Merged-by: Heinrich Lee Yu <heinrich@gitlab.com>
Approved-by: Brian Williams <bwilliams@gitlab.com>
Approved-by: Phillip Wells <pwells@gitlab.com>
Approved-by: Heinrich Lee Yu <heinrich@gitlab.com>
Reviewed-by: Niklas <mc.taucher2003@gmail.com>
Reviewed-by: Brian Williams <bwilliams@gitlab.com>
Co-authored-by: Niklas <mc.taucher2003@gmail.com>

app/graphql/types/issue_type.rb

@@ -65,6 +65,13 @@ class IssueType < BaseObject
     field :merge_requests_count, GraphQL::Types::Int, null: false,
                                                       description: 'Number of merge requests that close the issue on merge.',
                                                       resolver: Resolvers::MergeRequestsCountResolver
+
+    field :related_merge_requests, Types::MergeRequestType.connection_type,
+                                   null: true,
+                                   description: 'Merge requests related to the issue. This field can only be resolved for one issue in any single request.' do
+      extension ::Gitlab::Graphql::Limit::FieldCallCount, limit: 1
+    end
+
     field :relative_position, GraphQL::Types::Int, null: true,
                                                    description: 'Relative position of the issue (used for positioning in epic tree and issue boards).'
     field :upvotes, GraphQL::Types::Int,
@@ -180,6 +187,17 @@ def closed_as_duplicate_of
       Gitlab::Graphql::Loaders::BatchModelLoader.new(Issue, object.duplicated_to_id).find
     end
+    def related_merge_requests
+      # rubocop: disable CodeReuse/ActiveRecord
+      MergeRequest.where(
+        id: ::Issues::ReferencedMergeRequestsService.new(project: object.project, current_user: current_user)
+        .execute(object)
+        .first
+        .map(&:id)
+      )
+      # rubocop: enable CodeReuse/ActiveRecord
+    end
+
     def discussion_locked
       !!object.discussion_locked
     end

doc/api/graphql/reference/index.md

@@ -13263,6 +13263,7 @@ Relationship between an epic and an issue.
 | <a id="epicissuenotes"></a>`notes` | [`NoteConnection!`](#noteconnection) | All notes on this noteable. (see [Connections](#connections)) |
 | <a id="epicissueparticipants"></a>`participants` | [`UserCoreConnection`](#usercoreconnection) | List of participants in the issue. (see [Connections](#connections)) |
 | <a id="epicissueprojectid"></a>`projectId` | [`Int!`](#int) | ID of the issue project. |
+| <a id="epicissuerelatedmergerequests"></a>`relatedMergeRequests` | [`MergeRequestConnection`](#mergerequestconnection) | Merge requests related to the issue. This field can only be resolved for one issue in any single request. (see [Connections](#connections)) |
 | <a id="epicissuerelatedvulnerabilities"></a>`relatedVulnerabilities` | [`VulnerabilityConnection`](#vulnerabilityconnection) | Related vulnerabilities of the issue. (see [Connections](#connections)) |
 | <a id="epicissuerelationpath"></a>`relationPath` | [`String`](#string) | URI path of the epic-issue relation. |
 | <a id="epicissuerelativeposition"></a>`relativePosition` | [`Int`](#int) | Relative position of the issue (used for positioning in epic tree and issue boards). |
@@ -15009,6 +15010,7 @@ Describes an issuable resource link for incident issues.
 | <a id="issuenotes"></a>`notes` | [`NoteConnection!`](#noteconnection) | All notes on this noteable. (see [Connections](#connections)) |
 | <a id="issueparticipants"></a>`participants` | [`UserCoreConnection`](#usercoreconnection) | List of participants in the issue. (see [Connections](#connections)) |
 | <a id="issueprojectid"></a>`projectId` | [`Int!`](#int) | ID of the issue project. |
+| <a id="issuerelatedmergerequests"></a>`relatedMergeRequests` | [`MergeRequestConnection`](#mergerequestconnection) | Merge requests related to the issue. This field can only be resolved for one issue in any single request. (see [Connections](#connections)) |
 | <a id="issuerelatedvulnerabilities"></a>`relatedVulnerabilities` | [`VulnerabilityConnection`](#vulnerabilityconnection) | Related vulnerabilities of the issue. (see [Connections](#connections)) |
 | <a id="issuerelativeposition"></a>`relativePosition` | [`Int`](#int) | Relative position of the issue (used for positioning in epic tree and issue boards). |
 | <a id="issueseverity"></a>`severity` | [`IssuableSeverity`](#issuableseverity) | Severity level of the incident. |

spec/requests/api/graphql/issue/issue_spec.rb

@@ -154,6 +154,47 @@ def query(fields)
     end
   end
+  context 'when selecting `related_merge_requests`' do
+    let(:issue_fields) { ['relatedMergeRequests { nodes { id } }'] }
+    let_it_be(:user) { create(:user) }
+    let_it_be(:mr_project) { project }
+    let!(:merge_request) do
+      attributes = {
+        author: user,
+        source_project: mr_project,
+        target_project: mr_project,
+        source_branch: 'master',
+        target_branch: 'test',
+        description: "See #{issue.to_reference}"
+      }
+
+      create(:merge_request, attributes).tap do |merge_request|
+        create(:note, :system, project: issue.project, noteable: issue,
+          author: user, note: merge_request.to_reference(full: true))
+      end
+    end
+
+    before do
+      project.add_developer(current_user)
+
+      post_graphql(query, current_user: current_user)
+    end
+
+    it 'returns the related merge request' do
+      expect(issue_data['relatedMergeRequests']['nodes']).to include a_hash_including({
+        'id' => merge_request.to_global_id.to_s
+      })
+    end
+
+    context 'no permission to related merge request' do
+      let_it_be(:mr_project) { create(:project, :private) }
+
+      it 'does not return the related merge request' do
+        expect(issue_data['relatedMergeRequests']['nodes']).to be_empty
+      end
+    end
+  end
+
   context 'when there is a confidential issue' do
     let!(:confidential_issue) do
       create(:issue, :confidential, project: project)

spec/requests/api/graphql/project/alert_management/alerts_spec.rb

@@ -16,7 +16,7 @@
   let(:fields) do
     <<~QUERY
       nodes {
-        #{all_graphql_fields_for('AlertManagementAlert', excluded: ['assignees'])}
+        #{all_graphql_fields_for('AlertManagementAlert', excluded: %w[assignees relatedMergeRequests])}
       }
     QUERY
   end

spec/support/shared_examples/requests/api/graphql/issue_list_shared_examples.rb

@@ -5,7 +5,7 @@
   let(:fields) do
     <<~QUERY
     nodes {
-      #{all_graphql_fields_for('issues'.classify)}
+      #{all_graphql_fields_for('issues'.classify, excluded: ['relatedMergeRequests'])}
     }
     QUERY
   end
@@ -683,6 +683,28 @@ def assignees_as_global_ids(issues)
     end
   end
+  context 'when selecting `related_merge_requests`' do
+    let(:fields) do
+      <<~QUERY
+      nodes {
+        relatedMergeRequests {
+          nodes {
+            id
+          }
+        }
+      }
+      QUERY
+    end
+
+    it 'limits the field to 1 execution' do
+      post_query
+
+      expect_graphql_errors_to_include(
+        '"relatedMergeRequests" field can be requested only for 1 Issue(s) at a time.'
+      )
+    end
+  end
+
   it 'includes a web_url' do
     post_query