app/views/stripe/_js.html.erb
<%- stripe_js_version = Stripe::JavascriptHelper::DEFAULT_STRIPE_JS_VERSION if (!defined?(stripe_js_version) || stripe_js_version.nil?) %>
<%- case stripe_js_version %>
<%- when 'v1', 'v2' %>
<%- if ::Rails.application.config.stripe.debug_js %>
<script type="text/javascript" src="https://js.stripe.com/<%=stripe_js_version%>/stripe-debug.js"></script>
<%- else %>
<script type="text/javascript" src="https://js.stripe.com/<%=stripe_js_version%>/"></script>
<%- end %>
<script type="text/javascript">
Stripe.setPublishableKey("<%= Rails.application.config.stripe.publishable_key or fail 'No stripe.com publishable key found. Please set config.stripe.publishable_key in config/application.rb to one of your publishable keys, which can be found here: https://manage.stripe.com/#account/apikeys' %>")
</script>
<%- when 'v3' # the debug js for v3 isn't available %>
<script type="text/javascript" src="https://js.stripe.com/<%=stripe_js_version%>/"></script>
<script type="text/javascript">
var stripe = Stripe("<%= Rails.application.config.stripe.publishable_key or fail 'No stripe.com publishable key found. Please set config.stripe.publishable_key in config/application.rb to one of your publishable keys, which can be found here: https://manage.stripe.com/#account/apikeys' %>");
</script>
<%- end %>