ES modules (ESM) and circular deps gotchas

Q: How is it possible for an imported method to be undefined?!? A: Circular deps

Good reading:

https://stackoverflow.com/questions/34025599/when-using-es6-how-can-an-imported-function-be-undefined-in-one-file-and-not-i https://stackoverflow.com/questions/38841469/how-to-fix-this-es6-module-circular-dependency https://esdiscuss.org/topic/how-to-solve-this-basic-es6-module-circular-dependency-problem#content-21 https://spin.atomicobject.com/2018/06/25/circular-dependencies-javascript/

https://andrejsabrickis.medium.com/locate-circular-dependencies-in-typescript-modules-2b1eb03dbf2e https://javascript.info/import-export#re-export