Add Group.mergeRequests field

This allows one to request the merge requests for a particular group,
including all of its projects and subgroups.

This functionality is not available in any other way at present.

To achieve this, a new resolver is added: GroupMergeRequestResolver,
which is tested with request tests.

The following minor additions are made:

- The merge requests factory now is able to build merge requests with
  unique authors (this is helpful to distinguish querying by project and
  by author, since otherwise they are the same).

- Abstract out include_subgroups, author and assignee filters
  this moves some filter definitions to specialised DSL
  methods, so they can be used where it makes sense without repeating the
  field definitions.

app/graphql/resolvers/assigned_merge_requests_resolver.rb

@@ -2,6 +2,8 @@
 
 module Resolvers
   class AssignedMergeRequestsResolver < UserMergeRequestsResolver
+    accept_author
+
     def user_role
       :assignee
     end

app/graphql/resolvers/authored_merge_requests_resolver.rb

@@ -2,6 +2,8 @@
 
 module Resolvers
   class AuthoredMergeRequestsResolver < UserMergeRequestsResolver
+    accept_assignee
+
     def user_role
       :author
     end

app/graphql/resolvers/concerns/group_issuable_resolver.rb

+# frozen_string_literal: true
+
+module GroupIssuableResolver
+  extend ActiveSupport::Concern
+
+  class_methods do
+    def include_subgroups(name_of_things)
+      argument :include_subgroups, GraphQL::BOOLEAN_TYPE,
+               required: false,
+               default_value: false,
+               description: "Include #{name_of_things} belonging to subgroups"
+    end
+  end
+end

app/graphql/resolvers/concerns/resolves_merge_requests.rb

@@ -12,7 +12,7 @@ module ResolvesMergeRequests
 
   def resolve_with_lookahead(**args)
     mr_finder = MergeRequestsFinder.new(current_user, args.compact)
-    finder = Gitlab::Graphql::Loaders::IssuableLoader.new(project, mr_finder)
+    finder = Gitlab::Graphql::Loaders::IssuableLoader.new(mr_parent, mr_finder)
 
     select_result(finder.batching_find_all { |query| apply_lookahead(query) })
   end
@@ -29,6 +29,10 @@ module ResolvesMergeRequests
 
   private
 
+  def mr_parent
+    project
+  end
+
   def unconditional_includes
     [:target_project]
   end

app/graphql/resolvers/group_issues_resolver.rb

@@ -2,9 +2,8 @@
 
 module Resolvers
   class GroupIssuesResolver < IssuesResolver
-    argument :include_subgroups, GraphQL::BOOLEAN_TYPE,
-             required: false,
-             default_value: false,
-             description: 'Include issues belonging to subgroups.'
+    include GroupIssuableResolver
+
+    include_subgroups 'issues'
   end
 end

app/graphql/resolvers/group_merge_requests_resolver.rb

+# frozen_string_literal: true
+
+module Resolvers
+  class GroupMergeRequestsResolver < MergeRequestsResolver
+    include GroupIssuableResolver
+
+    alias_method :group, :synchronized_object
+
+    include_subgroups 'merge requests'
+    accept_assignee
+    accept_author
+
+    def project
+      nil
+    end
+
+    def mr_parent
+      group
+    end
+
+    def no_results_possible?(args)
+      group.nil? || some_argument_is_empty?(args)
+    end
+  end
+end

app/graphql/resolvers/merge_requests_resolver.rb

@@ -6,6 +6,18 @@ module Resolvers
 
     alias_method :project, :synchronized_object
 
+    def self.accept_assignee
+      argument :assignee_username, GraphQL::STRING_TYPE,
+             required: false,
+             description: 'Username of the assignee'
+    end
+
+    def self.accept_author
+      argument :author_username, GraphQL::STRING_TYPE,
+             required: false,
+             description: 'Username of the author'
+    end
+
     argument :iids, [GraphQL::STRING_TYPE],
               required: false,
               description: 'Array of IIDs of merge requests, for example `[1, 2]`'

app/graphql/resolvers/project_merge_requests_resolver.rb

@@ -2,11 +2,7 @@
 
 module Resolvers
   class ProjectMergeRequestsResolver < MergeRequestsResolver
-    argument :assignee_username, GraphQL::STRING_TYPE,
-             required: false,
-             description: 'Username of the assignee'
-    argument :author_username, GraphQL::STRING_TYPE,
-             required: false,
-             description: 'Username of the author'
+    accept_assignee
+    accept_author
   end
 end

app/graphql/types/group_type.rb

@@ -46,9 +46,15 @@ module Types
     field :issues,
           Types::IssueType.connection_type,
           null: true,
-          description: 'Issues of the group',
+          description: 'Issues for projects in this group',
           resolver: Resolvers::GroupIssuesResolver
 
+    field :merge_requests,
+          Types::MergeRequestType.connection_type,
+          null: true,
+          description: 'Merge requests for projects in this group',
+          resolver: Resolvers::GroupMergeRequestsResolver
+
     field :milestones, Types::MilestoneType.connection_type, null: true,
           description: 'Milestones of the group',
           resolver: Resolvers::GroupMilestonesResolver

changelogs/unreleased/ajk-graphql-group-mrs.yml

+---
+title: Enable querying for merge requests within a group
+merge_request: 43863
+author:
+type: added

doc/api/graphql/reference/gitlab_schema.graphql

@@ -7349,7 +7349,7 @@ type Group {
   isTemporaryStorageIncreaseEnabled: Boolean!
 
   """
-  Issues of the group
+  Issues for projects in this group
   """
   issues(
     """
@@ -7418,7 +7418,7 @@ type Group {
     iids: [String!]
 
     """
-    Include issues belonging to subgroups.
+    Include issues belonging to subgroups
     """
     includeSubgroups: Boolean = false
 
@@ -7585,6 +7585,91 @@ type Group {
   """
   mentionsDisabled: Boolean
 
+  """
+  Merge requests for projects in this group
+  """
+  mergeRequests(
+    """
+    Returns the elements in the list that come after the specified cursor.
+    """
+    after: String
+
+    """
+    Username of the assignee
+    """
+    assigneeUsername: String
+
+    """
+    Username of the author
+    """
+    authorUsername: String
+
+    """
+    Returns the elements in the list that come before the specified cursor.
+    """
+    before: String
+
+    """
+    Returns the first _n_ elements from the list.
+    """
+    first: Int
+
+    """
+    Array of IIDs of merge requests, for example `[1, 2]`
+    """
+    iids: [String!]
+
+    """
+    Include merge requests belonging to subgroups
+    """
+    includeSubgroups: Boolean = false
+
+    """
+    Array of label names. All resolved merge requests will have all of these labels.
+    """
+    labels: [String!]
+
+    """
+    Returns the last _n_ elements from the list.
+    """
+    last: Int
+
+    """
+    Merge requests merged after this date
+    """
+    mergedAfter: Time
+
+    """
+    Merge requests merged before this date
+    """
+    mergedBefore: Time
+
+    """
+    Title of the milestone
+    """
+    milestoneTitle: String
+
+    """
+    Sort merge requests by this criteria
+    """
+    sort: MergeRequestSort = created_desc
+
+    """
+    Array of source branch names. All resolved merge requests will have one of these branches as their source.
+    """
+    sourceBranches: [String!]
+
+    """
+    A merge request state. If provided, all resolved merge requests will have this state.
+    """
+    state: MergeRequestState
+
+    """
+    Array of target branch names. All resolved merge requests will have one of these branches as their target.
+    """
+    targetBranches: [String!]
+  ): MergeRequestConnection
+
   """
   Milestones of the group
   """
@@ -19124,6 +19209,11 @@ type User {
     """
     after: String
 
+    """
+    Username of the author
+    """
+    authorUsername: String
+
     """
     Returns the elements in the list that come before the specified cursor.
     """
@@ -19204,6 +19294,11 @@ type User {
     """
     after: String
 
+    """
+    Username of the assignee
+    """
+    assigneeUsername: String
+
     """
     Returns the elements in the list that come before the specified cursor.
     """

doc/api/graphql/reference/gitlab_schema.json

@@ -20302,7 +20302,7 @@
             },
             {
               "name": "issues",
-              "description": "Issues of the group",
+              "description": "Issues for projects in this group",
               "args": [
                 {
                   "name": "iid",
@@ -20532,7 +20532,7 @@
                 },
                 {
                   "name": "includeSubgroups",
-                  "description": "Include issues belonging to subgroups.",
+                  "description": "Include issues belonging to subgroups",
                   "type": {
                     "kind": "SCALAR",
                     "name": "Boolean",
@@ -20830,6 +20830,211 @@
               "isDeprecated": false,
               "deprecationReason": null
             },
+            {
+              "name": "mergeRequests",
+              "description": "Merge requests for projects in this group",
+              "args": [
+                {
+                  "name": "iids",
+                  "description": "Array of IIDs of merge requests, for example `[1, 2]`",
+                  "type": {
+                    "kind": "LIST",
+                    "name": null,
+                    "ofType": {
+                      "kind": "NON_NULL",
+                      "name": null,
+                      "ofType": {
+                        "kind": "SCALAR",
+                        "name": "String",
+                        "ofType": null
+                      }
+                    }
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "sourceBranches",
+                  "description": "Array of source branch names. All resolved merge requests will have one of these branches as their source.",
+                  "type": {
+                    "kind": "LIST",
+                    "name": null,
+                    "ofType": {
+                      "kind": "NON_NULL",
+                      "name": null,
+                      "ofType": {
+                        "kind": "SCALAR",
+                        "name": "String",
+                        "ofType": null
+                      }
+                    }
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "targetBranches",
+                  "description": "Array of target branch names. All resolved merge requests will have one of these branches as their target.",
+                  "type": {
+                    "kind": "LIST",
+                    "name": null,
+                    "ofType": {
+                      "kind": "NON_NULL",
+                      "name": null,
+                      "ofType": {
+                        "kind": "SCALAR",
+                        "name": "String",
+                        "ofType": null
+                      }
+                    }
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "state",
+                  "description": "A merge request state. If provided, all resolved merge requests will have this state.",
+                  "type": {
+                    "kind": "ENUM",
+                    "name": "MergeRequestState",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "labels",
+                  "description": "Array of label names. All resolved merge requests will have all of these labels.",
+                  "type": {
+                    "kind": "LIST",
+                    "name": null,
+                    "ofType": {
+                      "kind": "NON_NULL",
+                      "name": null,
+                      "ofType": {
+                        "kind": "SCALAR",
+                        "name": "String",
+                        "ofType": null
+                      }
+                    }
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "mergedAfter",
+                  "description": "Merge requests merged after this date",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Time",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "mergedBefore",
+                  "description": "Merge requests merged before this date",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Time",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "milestoneTitle",
+                  "description": "Title of the milestone",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "sort",
+                  "description": "Sort merge requests by this criteria",
+                  "type": {
+                    "kind": "ENUM",
+                    "name": "MergeRequestSort",
+                    "ofType": null
+                  },
+                  "defaultValue": "created_desc"
+                },
+                {
+                  "name": "includeSubgroups",
+                  "description": "Include merge requests belonging to subgroups",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Boolean",
+                    "ofType": null
+                  },
+                  "defaultValue": "false"
+                },
+                {
+                  "name": "assigneeUsername",
+                  "description": "Username of the assignee",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "authorUsername",
+                  "description": "Username of the author",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "after",
+                  "description": "Returns the elements in the list that come after the specified cursor.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "before",
+                  "description": "Returns the elements in the list that come before the specified cursor.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "first",
+                  "description": "Returns the first _n_ elements from the list.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Int",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "last",
+                  "description": "Returns the last _n_ elements from the list.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Int",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                }
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "MergeRequestConnection",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "milestones",
               "description": "Milestones of the group",
@@ -55847,6 +56052,16 @@
                   },
                   "defaultValue": null
                 },
+                {
+                  "name": "authorUsername",
+                  "description": "Username of the author",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
                 {
                   "name": "after",
                   "description": "Returns the elements in the list that come after the specified cursor.",
@@ -56042,6 +56257,16 @@
                   },
                   "defaultValue": null
                 },
+                {
+                  "name": "assigneeUsername",
+                  "description": "Username of the assignee",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
                 {
                   "name": "after",
                   "description": "Returns the elements in the list that come after the specified cursor.",

spec/factories/merge_requests.rb

@@ -164,6 +164,10 @@ FactoryBot.define do
       target_branch { generate(:branch) }
     end
 
+    trait :unique_author do
+      author { association(:user) }
+    end
+
     trait :with_coverage_reports do
       after(:build) do |merge_request|
         merge_request.head_pipeline = build(

spec/graphql/types/group_type_spec.rb

@@ -17,6 +17,7 @@ RSpec.describe GitlabSchema.types['Group'] do
       subgroup_creation_level require_two_factor_authentication
       two_factor_grace_period auto_devops_enabled emails_disabled
       mentions_disabled parent boards milestones group_members
+      merge_requests
     ]
 
     expect(described_class).to include_graphql_fields(*expected_fields)

spec/requests/api/graphql/group/merge_requests_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+# Based on ee/spec/requests/api/epics_spec.rb
+# Should follow closely in order to ensure all situations are covered
+RSpec.describe 'Query.group.mergeRequests' do
+  include GraphqlHelpers
+
+  let_it_be(:group)     { create(:group) }
+  let_it_be(:sub_group) { create(:group, parent: group) }
+
+  let_it_be(:project_a) { create(:project, :repository, group: group) }
+  let_it_be(:project_b) { create(:project, :repository, group: group) }
+  let_it_be(:project_c) { create(:project, :repository, group: sub_group) }
+  let_it_be(:project_x) { create(:project, :repository) }
+  let_it_be(:user)      { create(:user, developer_projects: [project_x]) }
+
+  let_it_be(:mr_attrs) do
+    { target_branch: 'master' }
+  end
+
+  let_it_be(:mr_traits) do
+    [:unique_branches, :unique_author]
+  end
+
+  let_it_be(:mrs_a, reload: true) { create_list(:merge_request, 2, *mr_traits, **mr_attrs, source_project: project_a) }
+  let_it_be(:mrs_b, reload: true) { create_list(:merge_request, 2, *mr_traits, **mr_attrs, source_project: project_b) }
+  let_it_be(:mrs_c, reload: true) { create_list(:merge_request, 2, *mr_traits, **mr_attrs, source_project: project_c) }
+  let_it_be(:other_mr) { create(:merge_request, source_project: project_x) }
+
+  let(:mrs_data) { graphql_data_at(:group, :merge_requests, :nodes) }
+
+  before do
+    group.add_developer(user)
+  end
+
+  def expected_mrs(mrs)
+    mrs.map { |mr| a_hash_including('id' => global_id_of(mr)) }
+  end
+
+  describe 'not passing any arguments' do
+    let(:query) do
+      <<~GQL
+      query($path: ID!) {
+        group(fullPath: $path) {
+          mergeRequests { nodes { id } }
+        }
+      }
+      GQL
+    end
+
+    it 'can find all merge requests in the group, excluding sub-groups' do
+      post_graphql(query, current_user: user, variables: { path: group.full_path })
+
+      expect(mrs_data).to match_array(expected_mrs(mrs_a + mrs_b))
+    end
+  end
+
+  describe 'restricting by author' do
+    let(:query) do
+      <<~GQL
+      query($path: ID!, $user: String) {
+        group(fullPath: $path) {
+          mergeRequests(authorUsername: $user) { nodes { id author { username } } }
+        }
+      }
+      GQL
+    end
+
+    let(:author) { mrs_b.first.author }
+
+    it 'can find all merge requests with user as author' do
+      post_graphql(query, current_user: user, variables: { user: author.username, path: group.full_path })
+
+      expect(mrs_data).to match_array(expected_mrs([mrs_b.first]))
+    end
+  end
+
+  describe 'restricting by assignee' do
+    let(:query) do
+      <<~GQL
+      query($path: ID!, $user: String) {
+        group(fullPath: $path) {
+          mergeRequests(assigneeUsername: $user) { nodes { id } }
+        }
+      }
+      GQL
+    end
+
+    let_it_be(:assignee) { create(:user) }
+
+    before_all do
+      mrs_b.second.assignees << assignee
+      mrs_a.first.assignees << assignee
+    end
+
+    it 'can find all merge requests assigned to user' do
+      post_graphql(query, current_user: user, variables: { user: assignee.username, path: group.full_path })
+
+      expect(mrs_data).to match_array(expected_mrs([mrs_a.first, mrs_b.second]))
+    end
+  end
+
+  describe 'passing include_subgroups: true' do
+    let(:query) do
+      <<~GQL
+      query($path: ID!) {
+        group(fullPath: $path) {
+          mergeRequests(includeSubgroups: true) { nodes { id } }
+        }
+      }
+      GQL
+    end
+
+    it 'can find all merge requests in the group, including sub-groups' do
+      post_graphql(query, current_user: user, variables: { path: group.full_path })
+
+      expect(mrs_data).to match_array(expected_mrs(mrs_a + mrs_b + mrs_c))
+    end
+  end
+end

spec/requests/api/graphql/user_query_spec.rb

@@ -29,15 +29,15 @@ RSpec.describe 'getting user information' do
     let_it_be(:unauthorized_user) { create(:user) }
 
     let_it_be(:assigned_mr) do
-      create(:merge_request, :unique_branches,
+      create(:merge_request, :unique_branches, :unique_author,
              source_project: project_a, assignees: [user])
     end
     let_it_be(:assigned_mr_b) do
-      create(:merge_request, :unique_branches,
+      create(:merge_request, :unique_branches, :unique_author,
              source_project: project_b, assignees: [user])
     end
     let_it_be(:assigned_mr_c) do
-      create(:merge_request, :unique_branches,
+      create(:merge_request, :unique_branches, :unique_author,
              source_project: project_b, assignees: [user])
     end
     let_it_be(:authored_mr) do
@@ -133,6 +133,17 @@ RSpec.describe 'getting user information' do
               )
             end
           end
+
+          context 'filtering by author' do
+            let(:author) { assigned_mr_b.author }
+            let(:mr_args) { { author_username: author.username } }
+
+            it 'finds the authored mrs' do
+              expect(assigned_mrs).to contain_exactly(
+                a_hash_including('id' => global_id_of(assigned_mr_b))
+              )
+            end
+          end
         end
 
         context 'the current user does not have access' do
@@ -172,6 +183,23 @@ RSpec.describe 'getting user information' do
             end
           end
 
+          context 'filtering by assignee' do
+            let(:assignee) { create(:user) }
+            let(:mr_args) { { assignee_username: assignee.username } }
+
+            it 'finds the assigned mrs' do
+              authored_mr.assignees << assignee
+              authored_mr_c.assignees << assignee
+
+              post_graphql(query, current_user: current_user)
+
+              expect(authored_mrs).to contain_exactly(
+                a_hash_including('id' => global_id_of(authored_mr)),
+                a_hash_including('id' => global_id_of(authored_mr_c))
+              )
+            end
+          end
+
           context 'filtering by project path and IID' do
             let(:mr_args) do
               { project_path: project_b.full_path, iids: [authored_mr_b.iid.to_s] }
@@ -253,8 +281,10 @@ RSpec.describe 'getting user information' do
           let(:current_user) { user }
 
           it 'can be found' do
-            expect(assigned_mrs).to include(
-              a_hash_including('id' => global_id_of(assigned_mr))
+            expect(assigned_mrs).to contain_exactly(
+              a_hash_including('id' => global_id_of(assigned_mr)),
+              a_hash_including('id' => global_id_of(assigned_mr_b)),
+              a_hash_including('id' => global_id_of(assigned_mr_c))
             )
           end
         end