Controller/Adminhtml/FastlyCdn/BasicAuthentication/CheckAuthSetting.php
public function execute()
    {
        $result = $this->resultJsonFactory->create();
        try {
            $activeVersion = $this->getRequest()->getParam('active_version');
            $snippets = $this->config->getVclSnippets(Config::VCL_AUTH_SNIPPET_PATH);

            foreach ($snippets as $key => $value) {
                $name = Config::FASTLY_MAGENTO_MODULE . '_basic_auth_' . $key;
                $status = $this->api->hasSnippet($activeVersion, $name);

                if ($status == false) {
                    return $result->setData([
                        'status' => false
                    ]);
                }
            }

            return $result->setData([
                'status' => true
            ]);
        } catch (\Exception $e) {
            return $result->setData([
                'status'    => false,
                'msg'       => $e->getMessage()
            ]);
        }
    }
public function execute()
    {
        $result = $this->resultJsonFactory->create();
        try {
            $activeVersion = $this->getRequest()->getParam('active_version');
            $snippets = $this->config->getVclSnippets(Config::VCL_AUTH_SNIPPET_PATH);

            foreach ($snippets as $key => $value) {
                $name = Config::FASTLY_MAGENTO_MODULE . '_basic_auth_' . $key;
                $status = $this->api->hasSnippet($activeVersion, $name);

                if ($status == false) {
                    return $result->setData([
                        'status' => false
                    ]);
                }
            }

            return $result->setData([
                'status' => true
            ]);
        } catch (\Exception $e) {
            return $result->setData([
                'status'    => false,
                'msg'       => $e->getMessage()
            ]);
        }
    }
Verifies weather or not auth settings snippet exists on specified Fastly version

@return \Magento\Framework\Controller\Result\Json