Occasional "'$' is undefined" error in Django template-rendered pages (production)

[gsidebo]

Steps to Reproduce

Not sure. Maybe slow down network connection in console

Expected Behavior

Javascript loads in Django-template-rendered pages

Actual Behavior

Certain scripts are occasionally executed before jQuery loads and $ is defined

Related Issues

Sentry: https://sentry.io/organizations/mit-office-of-digital-learning/issues/1085982154/events/4f28451f15ed4511864212b98b082a6e/?project=1413655

[sentry-io]

Sentry issue: XPRO-BT

[asadiqbal08]

Tried to re produce it but still not getting such error locally.

[asadiqbal08]

Is it still a valid bug ? as I tried it many times to generate it.

[gsidebo]

@asadiqbal08 It's still a valid bug. It was last seen today in production. I don't think we need to worry about reproducing it locally, though you can probably do that by clearing your browser cache and changing your network speed in the developer console. We should just apply some best-practice method for waiting for jQuery to load before executing any code that depends on it. Here's one blog post about that: https://idiallo.com/javascript/async-jquery. There might be a better solution out there but that's a start

[gsidebo]

This may have been solved as a result of our performance improvements (#2065). Closing.