Use the GraphQL Timeout plugin

as the TimeoutMiddleware is being deprecated

app/graphql/gitlab_schema.rb

@@ -16,6 +16,7 @@ class GitlabSchema < GraphQL::Schema
   use Gitlab::Graphql::CallsGitaly
   use Gitlab::Graphql::Connections
   use Gitlab::Graphql::GenericTracing
+  use Gitlab::Graphql::Timeout, max_seconds: Gitlab.config.gitlab.graphql_timeout
 
   query_analyzer Gitlab::Graphql::QueryAnalyzers::LoggerAnalyzer.new
   query_analyzer Gitlab::Graphql::QueryAnalyzers::RecursionAnalyzer.new

config/initializers/graphql.rb

@@ -5,7 +5,3 @@ GraphQL::Field.accepts_definitions(authorize: GraphQL::Define.assign_metadata_ke
 
 GraphQL::Schema::Object.accepts_definition(:authorize)
 GraphQL::Schema::Field.accepts_definition(:authorize)
-
-GitlabSchema.middleware << GraphQL::Schema::TimeoutMiddleware.new(max_seconds: Gitlab.config.gitlab.graphql_timeout) do |timeout_error, query|
-  Gitlab::GraphqlLogger.error(message: timeout_error.to_s, query: query.query_string, query_variables: query.provided_variables)
-end

lib/gitlab/graphql/timeout.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Graphql
+    class Timeout < GraphQL::Schema::Timeout
+      def handle_timeout(error, query)
+        Gitlab::GraphqlLogger.error(message: error.message, query: query.query_string, query_variables: query.provided_variables)
+      end
+    end
+  end
+end

spec/lib/gitlab/graphql/timeout_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Graphql::Timeout do
+  it 'inherits from ' do
+    expect(described_class.superclass).to eq GraphQL::Schema::Timeout
+  end
+
+  it 'sends the error to our GraphQL logger' do
+    parent_type = double(graphql_name: 'parent_type')
+    field = double(graphql_name: 'field')
+    query = double(query_string: 'query_string', provided_variables: 'provided_variables')
+    error = GraphQL::Schema::Timeout::TimeoutError.new(parent_type, field)
+
+    expect(Gitlab::GraphqlLogger)
+      .to receive(:error)
+      .with(message: 'Timeout on parent_type.field', query: 'query_string', query_variables: 'provided_variables')
+
+    timeout = described_class.new(max_seconds: 30)
+    timeout.handle_timeout(error, query)
+  end
+end

spec/requests/api/graphql/gitlab_schema_spec.rb

@@ -11,11 +11,11 @@ describe 'GitlabSchema configurations' do
     describe 'timeouts' do
       context 'when timeout is reached' do
         it 'shows an error' do
-          Timecop.scale(50000000) do # ludicrously large number because the timeout has to happen before the query even begins
-            subject
+          allow_any_instance_of(Gitlab::Graphql::Timeout).to receive(:max_seconds).and_return(0)
 
-            expect_graphql_errors_to_include /Timeout/
-          end
+          subject
+
+          expect_graphql_errors_to_include /Timeout/
         end
       end
     end
@@ -140,7 +140,7 @@ describe 'GitlabSchema configurations' do
     end
 
     it_behaves_like 'imposing query limits' do
-      it "fails all queries when only one of the queries is too complex" do
+      it 'fails all queries when only one of the queries is too complex' do
         # The `project` query above has a complexity of 5
         allow(GitlabSchema).to receive(:max_query_complexity).and_return 4