--strictPropertyInitialization
↔ flag to set TSC to throw error when properties in class
definitions are not initialized
References
tsc --strict
↔ to flag TSC auto-set max strictness settings, apply true to:--noImplicitAny
,--noImplicitThis
,--alwaysStrict
,--strictNullChecks
,--strictFunctionTypes
,--strictPropertyInitialization