Expose Path Locks in the GraphQL API

Path Locks are an EE-only feature that allow a user to prevent anyone
else from pushing changes to a certain path. We need to expose the
locks through GraphQL to convert the file view to GraphQL.

Changelog: added

doc/api/graphql/reference/index.md

@@ -5800,6 +5800,29 @@ The edge type for [`PackageTag`](#packagetag).
 | <a id="packagetagedgecursor"></a>`cursor` | [`String!`](#string) | A cursor for use in pagination. |
 | <a id="packagetagedgenode"></a>`node` | [`PackageTag`](#packagetag) | The item at the end of the edge. |
 
+#### `PathLockConnection`
+
+The connection type for [`PathLock`](#pathlock).
+
+##### Fields
+
+| Name | Type | Description |
+| ---- | ---- | ----------- |
+| <a id="pathlockconnectionedges"></a>`edges` | [`[PathLockEdge]`](#pathlockedge) | A list of edges. |
+| <a id="pathlockconnectionnodes"></a>`nodes` | [`[PathLock]`](#pathlock) | A list of nodes. |
+| <a id="pathlockconnectionpageinfo"></a>`pageInfo` | [`PageInfo!`](#pageinfo) | Information to aid in pagination. |
+
+#### `PathLockEdge`
+
+The edge type for [`PathLock`](#pathlock).
+
+##### Fields
+
+| Name | Type | Description |
+| ---- | ---- | ----------- |
+| <a id="pathlockedgecursor"></a>`cursor` | [`String!`](#string) | A cursor for use in pagination. |
+| <a id="pathlockedgenode"></a>`node` | [`PathLock`](#pathlock) | The item at the end of the edge. |
+
 #### `PipelineArtifactRegistryConnection`
 
 The connection type for [`PipelineArtifactRegistry`](#pipelineartifactregistry).
@@ -10613,6 +10636,18 @@ Information about pagination in a connection.
 | <a id="pageinfohaspreviouspage"></a>`hasPreviousPage` | [`Boolean!`](#boolean) | When paginating backwards, are there more items?. |
 | <a id="pageinfostartcursor"></a>`startCursor` | [`String`](#string) | When paginating backwards, the cursor to continue. |
 
+### `PathLock`
+
+Represents a file or directory in the project repository that has been locked.
+
+#### Fields
+
+| Name | Type | Description |
+| ---- | ---- | ----------- |
+| <a id="pathlockid"></a>`id` | [`PathLockID!`](#pathlockid) | ID of the path lock. |
+| <a id="pathlockpath"></a>`path` | [`String`](#string) | The locked path. |
+| <a id="pathlockuser"></a>`user` | [`UserCore`](#usercore) | The user that has locked this path. |
+
 ### `Pipeline`
 
 #### Fields
@@ -10827,6 +10862,7 @@ Represents vulnerability finding of a security report on the pipeline.
 | <a id="projectonlyallowmergeifpipelinesucceeds"></a>`onlyAllowMergeIfPipelineSucceeds` | [`Boolean`](#boolean) | Indicates if merge requests of the project can only be merged with successful jobs. |
 | <a id="projectopenissuescount"></a>`openIssuesCount` | [`Int`](#int) | Number of open issues for the project. |
 | <a id="projectpath"></a>`path` | [`String!`](#string) | Path of the project. |
+| <a id="projectpathlocks"></a>`pathLocks` | [`PathLockConnection`](#pathlockconnection) | The project's path locks. (see [Connections](#connections)) |
 | <a id="projectpipelineanalytics"></a>`pipelineAnalytics` | [`PipelineAnalytics`](#pipelineanalytics) | Pipeline analytics. |
 | <a id="projectprintingmergerequestlinkenabled"></a>`printingMergeRequestLinkEnabled` | [`Boolean`](#boolean) | Indicates if a link to create or view a merge request should display after a push to Git repositories of the project from the command line. |
 | <a id="projectpublicjobs"></a>`publicJobs` | [`Boolean`](#boolean) | Indicates if there is public access to pipelines and job details of the project, including output logs and artifacts. |
@@ -11641,6 +11677,7 @@ Represents a Project Membership.
 | Name | Type | Description |
 | ---- | ---- | ----------- |
 | <a id="projectpermissionsadminoperations"></a>`adminOperations` | [`Boolean!`](#boolean) | Indicates the user can perform `admin_operations` on this resource. |
+| <a id="projectpermissionsadminpathlocks"></a>`adminPathLocks` | [`Boolean!`](#boolean) | Indicates the user can perform `admin_path_locks` on this resource. |
 | <a id="projectpermissionsadminproject"></a>`adminProject` | [`Boolean!`](#boolean) | Indicates the user can perform `admin_project` on this resource. |
 | <a id="projectpermissionsadminremotemirror"></a>`adminRemoteMirror` | [`Boolean!`](#boolean) | Indicates the user can perform `admin_remote_mirror` on this resource. |
 | <a id="projectpermissionsadminwiki"></a>`adminWiki` | [`Boolean!`](#boolean) | Indicates the user can perform `admin_wiki` on this resource. |
@@ -15036,6 +15073,12 @@ A `PackagesPackageID` is a global ID. It is encoded as a string.
 
 An example `PackagesPackageID` is: `"gid://gitlab/Packages::Package/1"`.
 
+### `PathLockID`
+
+A `PathLockID` is a global ID. It is encoded as a string.
+
+An example `PathLockID` is: `"gid://gitlab/PathLock/1"`.
+
 ### `PayloadAlertFieldPathSegment`
 
 String or integer.

ee/app/graphql/ee/types/project_type.rb

@@ -142,6 +142,13 @@ module EE
               null: true,
               description: "The project's push rules settings.",
               method: :push_rule
+
+        field :path_locks,
+              ::Types::PathLockType.connection_type,
+              null: true,
+              description: "The project's path locks.",
+              extras: [:lookahead],
+              resolver: ::Resolvers::PathLocksResolver
       end
 
       def api_fuzzing_ci_configuration

ee/app/graphql/resolvers/path_locks_resolver.rb

+# frozen_string_literal: true
+
+module Resolvers
+  class PathLocksResolver < BaseResolver
+    include Gitlab::Graphql::Authorize::AuthorizeResource
+    include LooksAhead
+
+    authorize :download_code
+
+    type Types::PathLockType, null: true
+
+    alias_method :project, :object
+
+    def resolve_with_lookahead(**args)
+      authorize!(project)
+
+      return [] unless path_lock_feature_enabled?
+
+      find_path_locks(args)
+    end
+
+    private
+
+    def preloads
+      { user: [:user] }
+    end
+
+    def find_path_locks(args)
+      apply_lookahead(project.path_locks)
+    end
+
+    def path_lock_feature_enabled?
+      project.licensed_feature_available?(:file_locks)
+    end
+  end
+end

ee/app/graphql/types/path_lock_type.rb

+# frozen_string_literal: true
+module Types
+  class PathLockType < BaseObject # rubocop:disable Graphql/AuthorizeTypes
+    graphql_name 'PathLock'
+    description 'Represents a file or directory in the project repository that has been locked.'
+
+    field :id, ::Types::GlobalIDType[PathLock], null: false,
+          description: 'ID of the path lock.'
+
+    field :path, GraphQL::STRING_TYPE, null: true,
+          description: 'The locked path.'
+
+    field :user, ::Types::UserType, null: true,
+          description: 'The user that has locked this path.'
+  end
+end

ee/changelogs/unreleased/323195-path-locks-graphql.yml

+---
+title: Expose Path Locks in the GraphQL API
+merge_request: 61380
+author:
+type: added

ee/spec/graphql/resolvers/path_locks_resolver_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Resolvers::PathLocksResolver do
+  include GraphqlHelpers
+
+  let_it_be(:project) { create(:project) }
+  let_it_be(:path_lock) { create(:path_lock, path: 'README.md', project: project) }
+
+  let(:user) { project.owner }
+
+  describe '#resolve' do
+    subject(:resolve_path_locks) { resolve(described_class, obj: project, lookahead: positive_lookahead, ctx: { current_user: user }) }
+
+    context 'feature is not licensed' do
+      before do
+        stub_licensed_features(file_locks: false)
+      end
+
+      it { is_expected.to be_empty }
+    end
+
+    context 'feature is licensed' do
+      before do
+        stub_licensed_features(file_locks: true)
+      end
+
+      it { is_expected.to contain_exactly(path_lock) }
+
+      it 'preloads users' do
+        path_lock = resolve_path_locks.first
+
+        expect(path_lock.association_cached?(:user)).to be_truthy
+      end
+
+      context 'user is unauthorized' do
+        let(:user) { create(:user) }
+
+        it { expect { resolve_path_locks }.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable) }
+      end
+    end
+  end
+end

ee/spec/graphql/types/path_lock_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe GitlabSchema.types['PathLock'] do
+  it { expect(described_class.graphql_name).to eq('PathLock') }
+
+  it 'has the expected fields' do
+    expect(described_class).to have_graphql_fields(:id, :path, :user)
+  end
+end

ee/spec/graphql/types/project_type_spec.rb

@@ -20,7 +20,7 @@ RSpec.describe GitlabSchema.types['Project'] do
       vulnerabilities vulnerability_scanners requirement_states_count
       vulnerability_severities_count packages compliance_frameworks vulnerabilities_count_by_day
       security_dashboard_path iterations iteration_cadences cluster_agents repository_size_excess actual_repository_size_limit
-      code_coverage_summary api_fuzzing_ci_configuration
+      code_coverage_summary api_fuzzing_ci_configuration path_locks
     ]
 
     expect(described_class).to include_graphql_fields(*expected_fields)

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

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'Query.project(fullPath).pathLocks' do
+  using RSpec::Parameterized::TableSyntax
+  include GraphqlHelpers
+
+  let_it_be(:user) { create(:user) }
+  let_it_be(:project) { create(:project, namespace: user.namespace) }
+  let_it_be(:path_lock) { create(:path_lock, project: project, path: 'README.md') }
+
+  subject(:path_locks_response) do
+    post_graphql(
+      graphql_query_for(
+        :project, { full_path: project.full_path }, "pathLocks { nodes { #{all_graphql_fields_for('PathLock')} } }"
+      ),
+      current_user: user
+    )
+
+    graphql_data_at(:project, :pathLocks, :nodes)
+  end
+
+  context 'unlicensed feature' do
+    before do
+      stub_licensed_features(file_locks: false)
+    end
+
+    it { is_expected.to be_empty }
+  end
+
+  context 'licensed feature' do
+    before do
+      stub_licensed_features(file_locks: true)
+    end
+
+    it 'returns path locks' do
+      is_expected.to match_array(
+        a_hash_including('id' => path_lock.to_global_id.to_s, 'path' => 'README.md')
+      )
+    end
+  end
+end