Add members to project graphQL endpoint

- add ProjectMembersResolver calling the respective finder
- add members to project type

app/graphql/resolvers/project_members_resolver.rb

+# frozen_string_literal: true
+
+module Resolvers
+  class ProjectMembersResolver < BaseResolver
+    argument :search, GraphQL::STRING_TYPE,
+              required: false,
+              description: 'Search query'
+
+    type Types::ProjectMemberType, null: true
+
+    alias_method :project, :object
+
+    def resolve(**args)
+      return Member.none unless project.present?
+
+      MembersFinder
+        .new(project, context[:current_user], params: args)
+        .execute
+    end
+  end
+end

app/graphql/types/project_member_type.rb

+# frozen_string_literal: true
+
+module Types
+  class ProjectMemberType < BaseObject
+    graphql_name 'ProjectMember'
+    description 'Member of a project'
+
+    authorize :read_project
+
+    field :id, GraphQL::ID_TYPE, null: false,
+          description: 'ID of the member'
+
+    field :access_level, GraphQL::INT_TYPE, null: false,
+          description: 'Access level of the member'
+
+    field :user, Types::UserType, null: false,
+          description: 'User that is associated with the member object',
+          resolve: -> (obj, _args, _ctx) { Gitlab::Graphql::Loaders::BatchModelLoader.new(User, obj.user_id).find }
+  end
+end

app/graphql/types/project_type.rb

@@ -139,6 +139,11 @@ module Types
           description: 'Issues of the project',
           resolver: Resolvers::IssuesResolver
 
+    field :project_members,
+          Types::ProjectMemberType.connection_type,
+          description: 'Members of the project',
+          resolver: Resolvers::ProjectMembersResolver
+
     field :environments,
           Types::EnvironmentType.connection_type,
           null: true,

changelogs/unreleased/216145-project-members-graphql.yml

+---
+title: Add  members to project graphQL endpoint
+merge_request: 33418
+author:
+type: added

doc/api/graphql/reference/gitlab_schema.graphql

@@ -8632,6 +8632,36 @@ type Project {
   """
   printingMergeRequestLinkEnabled: Boolean
 
+  """
+  Members of the project
+  """
+  projectMembers(
+    """
+    Returns the elements in the list that come after the specified cursor.
+    """
+    after: 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
+
+    """
+    Returns the last _n_ elements from the list.
+    """
+    last: Int
+
+    """
+    Search query
+    """
+    search: String
+  ): ProjectMemberConnection
+
   """
   Indicates if there is public access to pipelines and job details of the project, including output logs and artifacts
   """
@@ -9018,6 +9048,61 @@ type ProjectEdge {
   node: Project
 }
 
+"""
+Member of a project
+"""
+type ProjectMember {
+  """
+  Access level of the member
+  """
+  accessLevel: Int!
+
+  """
+  ID of the member
+  """
+  id: ID!
+
+  """
+  User that is associated with the member object
+  """
+  user: User!
+}
+
+"""
+The connection type for ProjectMember.
+"""
+type ProjectMemberConnection {
+  """
+  A list of edges.
+  """
+  edges: [ProjectMemberEdge]
+
+  """
+  A list of nodes.
+  """
+  nodes: [ProjectMember]
+
+  """
+  Information to aid in pagination.
+  """
+  pageInfo: PageInfo!
+}
+
+"""
+An edge in a connection.
+"""
+type ProjectMemberEdge {
+  """
+  A cursor for use in pagination.
+  """
+  cursor: String!
+
+  """
+  The item at the end of the edge.
+  """
+  node: ProjectMember
+}
+
 type ProjectPermissions {
   """
   Indicates the user can perform `admin_operations` on this resource

doc/api/graphql/reference/gitlab_schema.json

@@ -25317,6 +25317,69 @@
               "isDeprecated": false,
               "deprecationReason": null
             },
+            {
+              "name": "projectMembers",
+              "description": "Members of the project",
+              "args": [
+                {
+                  "name": "search",
+                  "description": "Search query",
+                  "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": "ProjectMemberConnection",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "publicJobs",
               "description": "Indicates if there is public access to pipelines and job details of the project, including output logs and artifacts",
@@ -26329,6 +26392,185 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "OBJECT",
+          "name": "ProjectMember",
+          "description": "Member of a project",
+          "fields": [
+            {
+              "name": "accessLevel",
+              "description": "Access level of the member",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "Int",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "id",
+              "description": "ID of the member",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "ID",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "user",
+              "description": "User that is associated with the member object",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "OBJECT",
+                  "name": "User",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "OBJECT",
+          "name": "ProjectMemberConnection",
+          "description": "The connection type for ProjectMember.",
+          "fields": [
+            {
+              "name": "edges",
+              "description": "A list of edges.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "LIST",
+                "name": null,
+                "ofType": {
+                  "kind": "OBJECT",
+                  "name": "ProjectMemberEdge",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "nodes",
+              "description": "A list of nodes.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "LIST",
+                "name": null,
+                "ofType": {
+                  "kind": "OBJECT",
+                  "name": "ProjectMember",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "pageInfo",
+              "description": "Information to aid in pagination.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "OBJECT",
+                  "name": "PageInfo",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "OBJECT",
+          "name": "ProjectMemberEdge",
+          "description": "An edge in a connection.",
+          "fields": [
+            {
+              "name": "cursor",
+              "description": "A cursor for use in pagination.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "String",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "node",
+              "description": "The item at the end of the edge.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "ProjectMember",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "OBJECT",
           "name": "ProjectPermissions",

doc/api/graphql/reference/index.md

@@ -1258,6 +1258,16 @@ Information about pagination in a connection.
 | `webUrl` | String | Web URL of the project |
 | `wikiEnabled` | Boolean | Indicates if Wikis are enabled for the current user |
 
+## ProjectMember
+
+Member of a project
+
+| Name  | Type  | Description |
+| ---   |  ---- | ----------  |
+| `accessLevel` | Int! | Access level of the member |
+| `id` | ID! | ID of the member |
+| `user` | User! | User that is associated with the member object |
+
 ## ProjectPermissions
 
 | Name  | Type  | Description |

spec/graphql/resolvers/project_members_resolver_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Resolvers::ProjectMembersResolver do
+  include GraphqlHelpers
+
+  context "with a group" do
+    let_it_be(:root_group)   { create(:group) }
+    let_it_be(:group_1)      { create(:group, parent: root_group) }
+    let_it_be(:group_2)      { create(:group, parent: root_group) }
+    let_it_be(:project)      { create(:project, :public, group: group_1) }
+
+    let_it_be(:user_1) { create(:user, name: 'test user') }
+    let_it_be(:user_2) { create(:user, name: 'test user 2') }
+    let_it_be(:user_3) { create(:user, name: 'another user 1') }
+    let_it_be(:user_4) { create(:user, name: 'another user 2') }
+
+    let_it_be(:project_member)    { create(:project_member, user: user_1, project: project) }
+    let_it_be(:group_1_member)    { create(:group_member, user: user_2, group: group_1) }
+    let_it_be(:group_2_member)    { create(:group_member, user: user_3, group: group_2) }
+    let_it_be(:root_group_member) { create(:group_member, user: user_4, group: root_group) }
+
+    let(:args) { {} }
+
+    subject do
+      resolve(described_class, obj: project, args: args, ctx: { context: user_4 })
+    end
+
+    describe '#resolve' do
+      it 'finds all project members' do
+        expect(subject).to contain_exactly(project_member, group_1_member, root_group_member)
+      end
+
+      context 'with search' do
+        context 'when the search term matches a user' do
+          let(:args) { { search: 'test' } }
+
+          it 'searches users by user name' do
+            expect(subject).to contain_exactly(project_member, group_1_member)
+          end
+        end
+
+        context 'when the search term does not match any user' do
+          let(:args) { { search: 'nothing' } }
+
+          it 'is empty' do
+            expect(subject).to be_empty
+          end
+        end
+      end
+
+      context 'when project is nil' do
+        let(:project) { nil }
+
+        it 'returns nil' do
+          expect(subject).to be_empty
+        end
+      end
+    end
+  end
+end

spec/graphql/types/project_member_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe GitlabSchema.types['ProjectMember'] do
+  specify { expect(described_class.graphql_name).to eq('ProjectMember') }
+
+  it 'has the expected fields' do
+    expected_fields = %w[id accessLevel user]
+
+    expect(described_class).to have_graphql_fields(*expected_fields)
+  end
+
+  specify { expect(described_class).to require_graphql_authorizations(:read_project) }
+end

spec/graphql/types/project_type_spec.rb

@@ -95,6 +95,13 @@ describe GitlabSchema.types['Project'] do
     it { is_expected.to have_graphql_resolver(Resolvers::EnvironmentsResolver) }
   end
 
+  describe 'members field' do
+    subject { described_class.fields['projectMembers'] }
+
+    it { is_expected.to have_graphql_type(Types::ProjectMemberType.connection_type) }
+    it { is_expected.to have_graphql_resolver(Resolvers::ProjectMembersResolver) }
+  end
+
   describe 'boards field' do
     subject { described_class.fields['boards'] }