Add total count to GraphQL release data

This commit allows the GraphQL endpoint to return the total number of
releases in a project.

app/graphql/types/release_type.rb

@@ -5,6 +5,8 @@ module Types
     graphql_name 'Release'
     description 'Represents a release'
 
+    connection_type_class(Types::CountableConnectionType)
+
     authorize :read_release
 
     alias_method :release, :object

changelogs/unreleased/214241-update-releases-page-to-use-graphql-endpoint.yml

+---
+title: Add total count to GraphQL release data
+merge_request: 40147
+author:
+type: added

doc/api/graphql/reference/gitlab_schema.graphql

@@ -13109,6 +13109,11 @@ type ReleaseAssets {
 The connection type for Release.
 """
 type ReleaseConnection {
+  """
+  Total count of collection
+  """
+  count: Int!
+
   """
   A list of edges.
   """

doc/api/graphql/reference/gitlab_schema.json

@@ -38297,6 +38297,24 @@
           "name": "ReleaseConnection",
           "description": "The connection type for Release.",
           "fields": [
+            {
+              "name": "count",
+              "description": "Total count of collection",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "Int",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "edges",
               "description": "A list of edges.",

spec/requests/api/graphql/project/releases_spec.rb

@@ -14,6 +14,7 @@ RSpec.describe 'Query.project(fullPath).releases()' do
     graphql_query_for(:project, { fullPath: project.full_path },
     %{
       releases {
+        count
         nodes {
           tagName
           tagPath
@@ -53,6 +54,20 @@ RSpec.describe 'Query.project(fullPath).releases()' do
     stub_default_url_options(host: 'www.example.com')
   end
 
+  shared_examples 'correct total count' do
+    let(:data) { graphql_data.dig('project', 'releases') }
+
+    before do
+      create_list(:release, 2, project: project)
+
+      post_query
+    end
+
+    it 'returns the total count' do
+      expect(data['count']).to eq(project.releases.count)
+    end
+  end
+
   shared_examples 'full access to all repository-related fields' do
     describe 'repository-related fields' do
       before do
@@ -92,6 +107,8 @@ RSpec.describe 'Query.project(fullPath).releases()' do
         )
       end
     end
+
+    it_behaves_like 'correct total count'
   end
 
   shared_examples 'no access to any repository-related fields' do
@@ -119,6 +136,8 @@ RSpec.describe 'Query.project(fullPath).releases()' do
         )
       end
     end
+
+    it_behaves_like 'correct total count'
   end
 
   # editUrl is tested separately becuase its permissions