import test from 'ava' ; import { assert } from '../helpers/assert' ; import { False , True , IsNever } from '../../src' ; test ( 'Can ask if a string is of type "never"' , t => { type str = 'hi' ; assert < IsNever < str > , False > ( t ) ; assert < IsNever < never > , True > ( t ) ; assert < IsNever < 'hi' & 'hello' > , True > ( t ) ; } ) ;