import { expectType } from 'ts-expect' ; import { G , pipe } from '../..' ; describe ( 'isNull' , ( ) => { it ( 'provides correct types' , ( ) => { const x = null ; if ( G . isNull ( x ) ) { expectType < null > ( x ) ; } const y = null ; if ( G . isNull ( y ) ) { expectType < null > ( y ) ; } } ) ; it ( 'determines whether the provided value is null' , ( ) => { expect ( G . isNull ( undefined ) ) . toEqual ( false ) ; expect ( G . isNull ( null ) ) . toEqual ( true ) ; } ) ; it ( '*' , ( ) => { expect ( G . isNull ( null ) ) . toEqual ( true ) ; } ) ; } ) ; describe ( 'isNull (pipe)' , ( ) => { it ( '*' , ( ) => { expect ( pipe ( null , G . isNull ) ) . toEqual ( true ) ; } ) ; } ) ;