[good first issue] Error handling for wrong JS glue.

[munrocket]

Leaving this issue just for log purposes.

Uncaught (in promise) TypeError: r is not a function
    at as-bind.esm.js:1:8309
    at b.wasm:0xfb1
    at b.wasm:0xffa
    at test.a.<computed> (as-bind.esm.js:1:5649)
    at Object.test (as-bind.esm.js:1:8623)
    at init (main.js:23:8)

You can get this error really frequently if you wrote wrong JS glue for externref. All files in dist folder are minified so you can't understand what is going on.