Convert measurement api/v1/admin/* controller specs to request specs (#28005)

spec/requests/api/v1/admin/retention_spec.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe 'Admin Retention' do
+  let(:user)    { Fabricate(:user, role: UserRole.find_by(name: 'Admin')) }
+  let(:token)   { Fabricate(:accessible_access_token, resource_owner_id: user.id, scopes: scopes) }
+  let(:headers) { { 'Authorization' => "Bearer #{token.token}" } }
+  let(:account) { Fabricate(:account) }
+
+  describe 'GET /api/v1/admin/retention' do
+    context 'when not authorized' do
+      it 'returns http forbidden' do
+        post '/api/v1/admin/retention', params: { account_id: account.id, limit: 2 }
+
+        expect(response)
+          .to have_http_status(403)
+      end
+    end
+
+    context 'with correct scope' do
+      let(:scopes) { 'admin:read' }
+
+      it 'returns http success and status json' do
+        post '/api/v1/admin/retention', params: { account_id: account.id, limit: 2 }, headers: headers
+
+        expect(response)
+          .to have_http_status(200)
+
+        expect(body_as_json)
+          .to be_an(Array)
+      end
+    end
+  end
+end