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Discussion on: Advanced TypeScript: reinventing lodash.get

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Roger Padilla •

Thanks a lot for sharing this @tipsy_dev !

I'm building a library and this could be really useful there. Do you know if/how to add type-safety in the path of the properties via template literals? I mean, not to return undefined but to make the compiler ensure the path is a valid path.

E.g.

interface User {
  email?: string;
}

interface Group {
  name?: string;
  creator?: User;
}
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So if we do:

// compiles
GetFieldType<Group, 'creator.email'>;

// produces compilation error
GetFieldType<Group, 'creator.invalidPath'>;
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Is there a way to do this?