if ( JSON . parse ( 'false' ) as boolean ) { alert ( 'never happens' ) ; } if ( JSON . parse ( 'null' ) as null ) { alert ( 'never happens' ) ; } declare interface MyInterface { attr : string ; } const a = JSON . parse ( '{}' ) as any ; const b = JSON . parse ( '{}' ) as unknown ; const c = JSON . parse ( '{}' ) as MyInterface ; let d = JSON . parse ( '{}' ) as any ; let e = JSON . parse ( '{}' ) as unknown ; let f = JSON . parse ( '{}' ) as MyInterface ; { const JSON = { parse : ( a ) => a } ; let g = JSON . parse ( '{}' ) ; } export { } ;