src/index.ts(12,5): error TS2322: Type 'string' is not assignable to type 'number'.
src/index.ts(15,20): error TS2345: Argument of type '42' is not assignable to parameter of type 'User'.
src/util.ts(3,10): error TS2304: Cannot find name 'foo'.

Found 3 errors in 2 files.
