Best way to keep constants file

This style guide looks simple and nice. It would be really great if someone adds style guide for constants

Just use TypeScript handbook as reference. AFAIK there is no rule in current Angular styleguide for constants/static variables conventions: https://www.typescriptlang.org/docs/handbook/enums.html There was a rule in older style guide though: https://v2.angular.io/docs/ts/latest/guide/style-guide.html#!#03-02 Cheers!