As the application is static content, runtime variables are not applicable, however, variations in the application configuration at deploy time can, on occasions, be applicable, e.g. using a different Google Tag Manager (GTM) for production and non-production environments to ensure the analytics are not contaminated.
Within source control there are two tokens applied. The first is a build-time token, which captures the semantic version. This is constructed from a release prefix and build number. This ensure from a user/tester perspective, the running asset can be verified to build that created it.
function App() {
return (
<div className="App">
<header className="App-header">
<img src={logo} className="App-logo" alt="logo" />
<p>
Class B campervan comparison tool version @semver@
The second token is the GTM ID, this is deploy-time token.
<!DOCTYPE html>
<html lang="en">
<head>
<!-- Google Tag Manager -->
<script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
})(window,document,'script','dataLayer','@gtm-id@');</script>
<!-- End Google Tag Manager -->