[BUG] events_app.py is broken

[bryevdv]

With 2.1.1 release, this line fails:

        const {to_string} = Bokeh.require("core/util/pretty")

wiht the error:

Error: Cannot find module 'core/util/pretty'

cc @mattpap is this some old, bad usage, that should have already previously been udpated in the example? Or was is this a regression that should work and was broken #10188 ?

My guess is the former, and that this should be using import but I wanted to check for sure before labeling.

Edit: perhaps not, since the code in a CustomJS is not a module, import does not seem to work.

[mattpap]

I'm pretty sure there's a mismatch between the version of events_app example you are running and bokehjs' version. core/util/pretty is available on master and the example was updated accordingly. In release-2.1 branch there should be no such module and the example should use JSON.stringify().

[mattpap]

import can only be used at the top-level of modules, so unfortunately we can't use it in CustomJS. However, one can use dynamic imports, i.e. await import(),

[bryevdv]

You're right, I was looking at master. New habits take time