Next time you get a "Cannot read property <x> of undefined" error at runtime, take a moment to trace why it happened, then read https://shinesolutions.com/2017/

Next time you get a "Cannot read property <x> of undefined" error at runtime, take a moment to trace why it happened, then read https://shinesolutions.com/2017/01/06/writing-safer-code-with-typescript-strict-null-checks-type-guards/ https://shinesolutions.com/2017/01/06/writing-safer-code-wit...