Rationale from the rule's page:
AMD-style require([]) and CommonJS-style require("") statements are
environment-specific and more difficult to statically analyze.
ES2015-style imports are part of the JavaScript language specfication
and recommended as the path going forward. TypeScript will compile them
to environment-specific forms as needed.
Add tslint as a plugin to tsc, so that they will show up in vscode or
whatever editor people use. I only enabled two basic rules that I think
are very useful, prefer-const and no-var-keyword. Violations of these
rules were fixed with "tslint -p . --fix". There was one unused
variable (in the isExpandable) function that I removed by hand.
A JavaScript string is a falsy value - but an empty string is valid in these positions - so need to explicitly check for undefined instead of just falsy.
