import { isHex } from '@polkadot/util' ; export function supportProperHex ( Assertion ) { Assertion . addProperty ( 'properHex' , function ( this ) { const subject = this . _obj ; this . assert ( isHex ( subject ) , `Expected "${ subject }" to be a proper hex` , `Expected "${ subject }" not to be a proper hex` , 'proper hex (eg.: 0x1234567890123456789012345678901234567890)' , subject ) ; } ) ; }