As @mcyph points out in PR #42 , it is highly desirable that the code base is converted from JavaSscript to TypeScript :
"it would have been feasible to do the significant architectural changes (that we're already a substantial way through completing) without converting to TypeScript. Strictly enforcing and annotating types makes it clearer what input parameters are required and what types of return values are possible"

Raising this issue and assigning it to both @mcyph and @junsikshim as they are in the process of doing this