Add Namespace and ProjectStatistics to GraphQL API

We can query namespaces, and nested projects.

Projects now exposes statistics

20 files changed, 362 insertions, 5 deletions

diff --git a/app/graphql/resolvers/namespace_projects_resolver.rb b/app/graphql/resolvers/namespace_projects_resolver.rb
new file mode 100644
index 00000000000..677ea808aeb
--- /dev/null
+++ b/app/graphql/resolvers/namespace_projects_resolver.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Resolvers
+  class NamespaceProjectsResolver < BaseResolver
+    argument :include_subgroups, GraphQL::BOOLEAN_TYPE,
+             required: false,
+             default_value: false,
+             description: 'Include also subgroup projects'
+
+    type Types::ProjectType, null: true
+
+    alias_method :namespace, :object
+
+    def resolve(include_subgroups:)
+      # The namespace could have been loaded in batch by `BatchLoader`.
+      # At this point we need the `id` or the `full_path` of the namespace
+      # to query for projects, so make sure it's loaded and not `nil` before continuing.
+      namespace.sync if namespace.respond_to?(:sync)
+      return Project.none if namespace.nil?
+
+      if include_subgroups
+        namespace.all_projects.with_route
+      else
+        namespace.projects.with_route
+      end
+    end
+
+    def self.resolver_complexity(args, child_complexity:)
+      complexity = super
+      complexity + 10
+    end
+  end
+end
diff --git a/app/graphql/resolvers/namespace_resolver.rb b/app/graphql/resolvers/namespace_resolver.rb
new file mode 100644
index 00000000000..17b3800d151
--- /dev/null
+++ b/app/graphql/resolvers/namespace_resolver.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Resolvers
+  class NamespaceResolver < BaseResolver
+    prepend FullPathResolver
+
+    type Types::NamespaceType, null: true
+
+    def resolve(full_path:)
+      model_by_full_path(Namespace, full_path)
+    end
+  end
+end
diff --git a/app/graphql/types/namespace_type.rb b/app/graphql/types/namespace_type.rb
index 36d8ee8c878..f6d91320e50 100644
--- a/app/graphql/types/namespace_type.rb
+++ b/app/graphql/types/namespace_type.rb
@@ -15,5 +15,10 @@ module Types
     field :visibility, GraphQL::STRING_TYPE, null: true
     field :lfs_enabled, GraphQL::BOOLEAN_TYPE, null: true, method: :lfs_enabled?
     field :request_access_enabled, GraphQL::BOOLEAN_TYPE, null: true
+
+    field :projects,
+          Types::ProjectType.connection_type,
+          null: false,
+          resolver: ::Resolvers::NamespaceProjectsResolver
   end
 end
diff --git a/app/graphql/types/project_statistics_type.rb b/app/graphql/types/project_statistics_type.rb
new file mode 100644
index 00000000000..35ae23c21fc
--- /dev/null
+++ b/app/graphql/types/project_statistics_type.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module Types
+  class ProjectStatisticsType < BaseObject
+    graphql_name 'ProjectStatistics'
+
+    field :commit_count, GraphQL::INT_TYPE, null: false
+
+    field :storage_size, GraphQL::INT_TYPE, null: false
+    field :repository_size, GraphQL::INT_TYPE, null: false
+    field :lfs_objects_size, GraphQL::INT_TYPE, null: false
+    field :build_artifacts_size, GraphQL::INT_TYPE, null: false
+    field :packages_size, GraphQL::INT_TYPE, null: false
+  end
+end
diff --git a/app/graphql/types/project_type.rb b/app/graphql/types/project_type.rb
index 06a1aab09f6..2236ffa394d 100644
--- a/app/graphql/types/project_type.rb
+++ b/app/graphql/types/project_type.rb
@@ -69,6 +69,10 @@ module Types
     field :namespace, Types::NamespaceType, null: false
     field :group, Types::GroupType, null: true
 
+    field :statistics, Types::ProjectStatisticsType,
+          null: false,
+          resolve: -> (obj, _args, _ctx) { Gitlab::Graphql::Loaders::BatchProjectStatisticsLoader.new(obj.id).find }
+
     field :repository, Types::RepositoryType, null: false
 
     field :merge_requests,
diff --git a/app/graphql/types/query_type.rb b/app/graphql/types/query_type.rb
index 40d7de1a49a..536bdb077ad 100644
--- a/app/graphql/types/query_type.rb
+++ b/app/graphql/types/query_type.rb
@@ -14,6 +14,11 @@ module Types
           resolver: Resolvers::GroupResolver,
           description: "Find a group"
 
+    field :namespace, Types::NamespaceType,
+          null: true,
+          resolver: Resolvers::NamespaceResolver,
+          description: "Find a namespace"
+
     field :metadata, Types::MetadataType,
           null: true,
           resolver: Resolvers::MetadataResolver,
diff --git a/app/models/project_statistics.rb b/app/models/project_statistics.rb
index dd0654aec0b..11e3737298c 100644
--- a/app/models/project_statistics.rb
+++ b/app/models/project_statistics.rb
@@ -16,6 +16,8 @@ class ProjectStatistics < ApplicationRecord
   COLUMNS_TO_REFRESH = [:repository_size, :wiki_size, :lfs_objects_size, :commit_count].freeze
   INCREMENTABLE_COLUMNS = { build_artifacts_size: %i[storage_size], packages_size: %i[storage_size] }.freeze
 
+  scope :for_project_ids, ->(project_ids) { where(project_id: project_ids) }
+
   def total_repository_size
     repository_size + lfs_objects_size
   end
diff --git a/changelogs/unreleased/ac-graphql-stats.yml b/changelogs/unreleased/ac-graphql-stats.yml
new file mode 100644
index 00000000000..8837dce4d89
--- /dev/null
+++ b/changelogs/unreleased/ac-graphql-stats.yml
@@ -0,0 +1,5 @@
+---
+title: Add Namespace and ProjectStatistics to GraphQL API
+merge_request: 28277
+author:
+type: added
diff --git a/doc/api/graphql/index.md b/doc/api/graphql/index.md
index 9195ba4cdf1..88e657a5d2f 100644
--- a/doc/api/graphql/index.md
+++ b/doc/api/graphql/index.md
@@ -47,6 +47,7 @@ A first iteration of a GraphQL API includes the following queries
 
 1. `project` : Within a project it is also possible to fetch a `mergeRequest` by IID.
 1. `group` : Only basic group information is currently supported.
+1. `namespace` : Within a namespace it is also possible to fetch `projects`.
 
 ### Multiplex queries
 
diff --git a/lib/gitlab/graphql/loaders/batch_project_statistics_loader.rb b/lib/gitlab/graphql/loaders/batch_project_statistics_loader.rb
new file mode 100644
index 00000000000..5e151f4dbd7
--- /dev/null
+++ b/lib/gitlab/graphql/loaders/batch_project_statistics_loader.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Graphql
+    module Loaders
+      class BatchProjectStatisticsLoader
+        attr_reader :project_id
+
+        def initialize(project_id)
+          @project_id = project_id
+        end
+
+        def find
+          BatchLoader.for(project_id).batch do |project_ids, loader|
+            ProjectStatistics.for_project_ids(project_ids).each do |statistics|
+              loader.call(statistics.project_id, statistics)
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/graphql/resolvers/namespace_projects_resolver_spec.rb b/spec/graphql/resolvers/namespace_projects_resolver_spec.rb
new file mode 100644
index 00000000000..395e08081d3
--- /dev/null
+++ b/spec/graphql/resolvers/namespace_projects_resolver_spec.rb
@@ -0,0 +1,69 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Resolvers::NamespaceProjectsResolver, :nested_groups do
+  include GraphqlHelpers
+
+  let(:current_user) { create(:user) }
+
+  context "with a group" do
+    let(:group) { create(:group) }
+    let(:namespace) { group }
+    let(:project1) { create(:project, namespace: namespace) }
+    let(:project2) { create(:project, namespace: namespace) }
+    let(:nested_group) { create(:group, parent: group) }
+    let(:nested_project) { create(:project, group: nested_group) }
+
+    before do
+      project1.add_developer(current_user)
+      project2.add_developer(current_user)
+      nested_project.add_developer(current_user)
+    end
+
+    describe '#resolve' do
+      it 'finds all projects' do
+        expect(resolve_projects).to contain_exactly(project1, project2)
+      end
+
+      it 'finds all projects including the subgroups' do
+        expect(resolve_projects(include_subgroups: true)).to contain_exactly(project1, project2, nested_project)
+      end
+
+      context 'with an user namespace' do
+        let(:namespace) { current_user.namespace }
+
+        it 'finds all projects' do
+          expect(resolve_projects).to contain_exactly(project1, project2)
+        end
+
+        it 'finds all projects including the subgroups' do
+          expect(resolve_projects(include_subgroups: true)).to contain_exactly(project1, project2)
+        end
+      end
+    end
+  end
+
+  context "when passing a non existent, batch loaded namespace" do
+    let(:namespace) do
+      BatchLoader.for("non-existent-path").batch do |_fake_paths, loader, _|
+        loader.call("non-existent-path", nil)
+      end
+    end
+
+    it "returns nil without breaking" do
+      expect(resolve_projects).to be_empty
+    end
+  end
+
+  it 'has an high complexity regardless of arguments' do
+    field = Types::BaseField.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: described_class, null: false, max_page_size: 100)
+
+    expect(field.to_graphql.complexity.call({}, {}, 1)).to eq 24
+    expect(field.to_graphql.complexity.call({}, { include_subgroups: true }, 1)).to eq 24
+  end
+
+  def resolve_projects(args = { include_subgroups: false }, context = { current_user: current_user })
+    resolve(described_class, obj: namespace, args: args, ctx: context)
+  end
+end
diff --git a/spec/graphql/types/namespace_type.rb b/spec/graphql/types/namespace_type_spec.rb
index 7cd6a79ae5d..b4144cc4121 100644
--- a/spec/graphql/types/namespace_type.rb
+++ b/spec/graphql/types/namespace_type_spec.rb
@@ -4,4 +4,6 @@ require 'spec_helper'
 
 describe GitlabSchema.types['Namespace'] do
   it { expect(described_class.graphql_name).to eq('Namespace') }
+
+  it { expect(described_class).to have_graphql_field(:projects) }
 end
diff --git a/spec/graphql/types/project_statistics_type_spec.rb b/spec/graphql/types/project_statistics_type_spec.rb
new file mode 100644
index 00000000000..485e194edb1
--- /dev/null
+++ b/spec/graphql/types/project_statistics_type_spec.rb
@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe GitlabSchema.types['ProjectStatistics'] do
+  it "has all the required fields" do
+    is_expected.to have_graphql_fields(:storage_size, :repository_size, :lfs_objects_size,
+                                       :build_artifacts_size, :packages_size, :commit_count)
+  end
+end
diff --git a/spec/graphql/types/project_type_spec.rb b/spec/graphql/types/project_type_spec.rb
index 075fa7c7e43..cb5ac2e3cb1 100644
--- a/spec/graphql/types/project_type_spec.rb
+++ b/spec/graphql/types/project_type_spec.rb
@@ -19,4 +19,6 @@ describe GitlabSchema.types['Project'] do
   it { is_expected.to have_graphql_field(:pipelines) }
 
   it { is_expected.to have_graphql_field(:repository) }
+
+  it { is_expected.to have_graphql_field(:statistics) }
 end
diff --git a/spec/graphql/types/query_type_spec.rb b/spec/graphql/types/query_type_spec.rb
index b4626955816..af1972a2513 100644
--- a/spec/graphql/types/query_type_spec.rb
+++ b/spec/graphql/types/query_type_spec.rb
@@ -5,7 +5,17 @@ describe GitlabSchema.types['Query'] do
     expect(described_class.graphql_name).to eq('Query')
   end
 
-  it { is_expected.to have_graphql_fields(:project, :group, :echo, :metadata) }
+  it { is_expected.to have_graphql_fields(:project, :namespace, :group, :echo, :metadata) }
+
+  describe 'namespace field' do
+    subject { described_class.fields['namespace'] }
+
+    it 'finds namespaces by full path' do
+      is_expected.to have_graphql_arguments(:full_path)
+      is_expected.to have_graphql_type(Types::NamespaceType)
+      is_expected.to have_graphql_resolver(Resolvers::NamespaceResolver)
+    end
+  end
 
   describe 'project field' do
     subject { described_class.fields['project'] }
diff --git a/spec/lib/gitlab/graphql/loaders/batch_project_statistics_loader_spec.rb b/spec/lib/gitlab/graphql/loaders/batch_project_statistics_loader_spec.rb
new file mode 100644
index 00000000000..ec2fcad31e5
--- /dev/null
+++ b/spec/lib/gitlab/graphql/loaders/batch_project_statistics_loader_spec.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Graphql::Loaders::BatchProjectStatisticsLoader do
+  describe '#find' do
+    it 'only queries once for project statistics' do
+      stats = create_list(:project_statistics, 2)
+      project1 = stats.first.project
+      project2 = stats.last.project
+
+      expect do
+        described_class.new(project1.id).find
+        described_class.new(project2.id).find
+      end.not_to exceed_query_limit(1)
+    end
+  end
+end
diff --git a/spec/models/project_statistics_spec.rb b/spec/models/project_statistics_spec.rb
index f985c114d4b..358873f9a2f 100644
--- a/spec/models/project_statistics_spec.rb
+++ b/spec/models/project_statistics_spec.rb
@@ -11,6 +11,20 @@ describe ProjectStatistics do
     it { is_expected.to belong_to(:namespace) }
   end
 
+  describe 'scopes' do
+    describe '.for_project_ids' do
+      it 'returns only requested projects' do
+        stats = create_list(:project_statistics, 3)
+        project_ids = stats[0..1].map { |s| s.project_id }
+        expected_ids = stats[0..1].map { |s| s.id }
+
+        requested_stats = described_class.for_project_ids(project_ids).pluck(:id)
+
+        expect(requested_stats).to eq(expected_ids)
+      end
+    end
+  end
+
   describe 'statistics columns' do
     it "support values up to 8 exabytes" do
       statistics.update!(
diff --git a/spec/requests/api/graphql/group_query_spec.rb b/spec/requests/api/graphql/group_query_spec.rb
index 8ff95cc9af2..db9f2ac9dd0 100644
--- a/spec/requests/api/graphql/group_query_spec.rb
+++ b/spec/requests/api/graphql/group_query_spec.rb
@@ -86,17 +86,18 @@ describe 'getting group information' do
       end
 
       it 'avoids N+1 queries' do
-        post_graphql(group_query(group1), current_user: admin)
-
         control_count = ActiveRecord::QueryRecorder.new do
           post_graphql(group_query(group1), current_user: admin)
         end.count
 
-        create(:project, namespace: group1)
+        queries = [{ query: group_query(group1) },
+                   { query: group_query(group2) }]
 
         expect do
-          post_graphql(group_query(group1), current_user: admin)
+          post_multiplex(queries, current_user: admin)
         end.not_to exceed_query_limit(control_count)
+
+        expect(graphql_errors).to contain_exactly(nil, nil)
       end
     end
 
diff --git a/spec/requests/api/graphql/namespace/projects_spec.rb b/spec/requests/api/graphql/namespace/projects_spec.rb
new file mode 100644
index 00000000000..e05273da4bd
--- /dev/null
+++ b/spec/requests/api/graphql/namespace/projects_spec.rb
@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'getting projects', :nested_groups do
+  include GraphqlHelpers
+
+  let(:group)             { create(:group) }
+  let!(:project)          { create(:project, namespace: subject) }
+  let(:nested_group)      { create(:group, parent: group) }
+  let!(:nested_project)   { create(:project, group: nested_group) }
+  let!(:public_project)   { create(:project, :public, namespace: subject) }
+  let(:user)              { create(:user) }
+  let(:include_subgroups) { true }
+
+  subject { group }
+
+  let(:query) do
+    graphql_query_for(
+      'namespace',
+      { 'fullPath' => subject.full_path },
+      <<~QUERY
+      projects(includeSubgroups: #{include_subgroups}) {
+        edges {
+          node {
+            #{all_graphql_fields_for('Project')}
+          }
+        }
+      }
+      QUERY
+    )
+  end
+
+  before do
+    group.add_owner(user)
+  end
+
+  shared_examples 'a graphql namespace' do
+    it_behaves_like 'a working graphql query' do
+      before do
+        post_graphql(query, current_user: user)
+      end
+    end
+
+    it "includes the packages size if the user can read the statistics" do
+      post_graphql(query, current_user: user)
+
+      count = if include_subgroups
+                subject.all_projects.count
+              else
+                subject.projects.count
+              end
+
+      expect(graphql_data['namespace']['projects']['edges'].size).to eq(count)
+    end
+
+    context 'with no user' do
+      it 'finds only public projects' do
+        post_graphql(query, current_user: nil)
+
+        expect(graphql_data['namespace']['projects']['edges'].size).to eq(1)
+        project = graphql_data['namespace']['projects']['edges'][0]['node']
+        expect(project['id']).to eq(public_project.id.to_s)
+      end
+    end
+  end
+
+  it_behaves_like 'a graphql namespace'
+
+  context 'when the namespace is a user' do
+    subject { user.namespace }
+    let(:include_subgroups) { false }
+
+    it_behaves_like 'a graphql namespace'
+  end
+
+  context 'when not including subgroups' do
+    let(:include_subgroups) { false }
+
+    it_behaves_like 'a graphql namespace'
+  end
+end
diff --git a/spec/requests/api/graphql/project/project_statistics_spec.rb b/spec/requests/api/graphql/project/project_statistics_spec.rb
new file mode 100644
index 00000000000..8683fa1f390
--- /dev/null
+++ b/spec/requests/api/graphql/project/project_statistics_spec.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'rendering namespace statistics' do
+  include GraphqlHelpers
+
+  let(:project) { create(:project) }
+  let!(:project_statistics) { create(:project_statistics, project: project, packages_size: 5.megabytes) }
+  let(:user) { create(:user) }
+
+  let(:query) do
+    graphql_query_for('project',
+                      { 'fullPath' => project.full_path },
+                      "statistics { #{all_graphql_fields_for('ProjectStatistics')} }")
+  end
+
+  before do
+    project.add_reporter(user)
+  end
+
+  it_behaves_like 'a working graphql query' do
+    before do
+      post_graphql(query, current_user: user)
+    end
+  end
+
+  it "includes the packages size if the user can read the statistics" do
+    post_graphql(query, current_user: user)
+
+    expect(graphql_data['project']['statistics']['packagesSize']).to eq(5.megabytes)
+  end
+
+  context 'when the project is public' do
+    let(:project) { create(:project, :public) }
+
+    it 'includes the statistics regardless of the user' do
+      post_graphql(query, current_user: nil)
+
+      expect(graphql_data['project']['statistics']).to be_present
+    end
+  end
+end