Add missing calls_gitaly to fields

Our CallsGitaly::Instrumentation notifies us if a field is calling
Gitaly without being marked as such:
https://gitlab.com/gitlab-org/gitlab/-/blob/035e73598f8910b95b902b30dd3bcae7b3cd5d8d/lib/gitlab/graphql/calls_gitaly/instrumentation.rb#L34-35

We can see notifications in Sentry for these fields, so adding the
missing `calls_gitaly: true` properties to the fields.

app/graphql/types/repository_type.rb

@@ -10,7 +10,7 @@ module Types
           description: 'Default branch of the repository'
     field :empty, GraphQL::BOOLEAN_TYPE, null: false, method: :empty?, calls_gitaly: true,
           description: 'Indicates repository has no visible content'
-    field :exists, GraphQL::BOOLEAN_TYPE, null: false, method: :exists?,
+    field :exists, GraphQL::BOOLEAN_TYPE, null: false, method: :exists?, calls_gitaly: true,
           description: 'Indicates a corresponding Git repository exists on disk'
     field :tree, Types::Tree::TreeType, null: true, resolver: Resolvers::TreeResolver, calls_gitaly: true,
           description: 'Tree of the repository'

changelogs/unreleased/ld-add-calls-gitaly-to-fields.yml

+---
+title: Increase the complexity score of GraphQL MergeRequest#approved, MergeRequest#approvalsLeft
+  and Repository#exists fields as they can call Gitaly
+merge_request: 47039
+author:
+type: changed

ee/app/graphql/ee/types/merge_request_type.rb

@@ -6,9 +6,9 @@ module EE
       extend ActiveSupport::Concern
 
       prepended do
-        field :approved, GraphQL::BOOLEAN_TYPE, method: :approved?, null: false,
+        field :approved, GraphQL::BOOLEAN_TYPE, method: :approved?, null: false, calls_gitaly: true,
               description: 'Indicates if the merge request has all the required approvals. Returns true if no required approvals are configured.'
-        field :approvals_left, GraphQL::INT_TYPE, null: true,
+        field :approvals_left, GraphQL::INT_TYPE, null: true, calls_gitaly: true,
               description: 'Number of approvals left'
         field :approvals_required, GraphQL::INT_TYPE, null: true,
               description: 'Number of approvals required'

ee/spec/graphql/ee/types/merge_request_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe GitlabSchema.types['MergeRequest'] do
+  it { expect(described_class).to have_graphql_fields(:approvals_required, :merge_trains_count).at_least }
+  it { expect(described_class).to have_graphql_field(:approved, complexity: 2, calls_gitaly?: true) }
+  it { expect(described_class).to have_graphql_field(:approvals_left, complexity: 2, calls_gitaly?: true) }
+end

spec/graphql/types/merge_request_type_spec.rb

@@ -32,14 +32,7 @@ RSpec.describe GitlabSchema.types['MergeRequest'] do
       has_ci mergeable commits_without_merge_commits squash security_auto_fix default_squash_commit_message
     ]
 
-    if Gitlab.ee?
-      expected_fields << 'approved'
-      expected_fields << 'approvals_left'
-      expected_fields << 'approvals_required'
-      expected_fields << 'merge_trains_count'
-    end
-
-    expect(described_class).to have_graphql_fields(*expected_fields)
+    expect(described_class).to have_graphql_fields(*expected_fields).at_least
   end
 
   describe '#pipelines' do

spec/graphql/types/repository_type_spec.rb

@@ -10,4 +10,6 @@ RSpec.describe GitlabSchema.types['Repository'] do
   specify { expect(described_class).to have_graphql_field(:root_ref) }
 
   specify { expect(described_class).to have_graphql_field(:tree) }
+
+  specify { expect(described_class).to have_graphql_field(:exists, calls_gitaly?: true, complexity: 2) }
 end