Well Typescript is really a static code analyser for Javascript and not a language, since it does nothing at runtime, and that's fine, its type system can catch a broad range of issues and improve code quality drastically. It's a huge godsend for big codebases. But afaik it doesn't guard against null by default.

A simpler example:

    declare type Foo = {name:String};
    declare function getFoo():Foo|null;

    const f = getFoo();
    if(f!==null) // mandatory or yields an error
        console.log(f.name);

But afaik it doesn't guard against null by default.