Duns.assert should be able to take a message

[br0r]

Duns.assert('ninja', Duns.number(), 'Not a valid number');
// Error{name: 'Duns Error', message: 'Not a valid number'}

Otherwise you would have to do this in tests:

try {
  Duns.assert('ninja', Duns.number());
} catch (err) {
  throw new Error('Invalid number');
}

Kind of defeats the purpose with .assert

[silfverstrom]

+1