Extending should.js with a custom function

Question

I've got a simple lodash mixin:

var _ = require('lodash')
_.mixin(require('lodash-uuid'))

Which I can use in code like so:

if (_.isUuid(someValue)) {
   // it's a uuid!
}

I'd like to be able to extend should.js-based tests to leverage this module, for example:

response.should.have.property('uuid').which.is.a.uuid()

The docs for extending Should are a little light; I tried:

var uuid = should.extend('uuid', _.isUuid)

But that throws:

TypeError: response.should.have.property(...).which.is.a.uuid is not a function

score 2 · Accepted Answer · answered Jan 08 '16 at 19:14

2

You used not right method. Method you used is to add should getter to any object. You need to use should.Assertion.add, like:

var should = require('should');

should.Assertion.add('uuid', function() {
  this.params = { operator: 'to be UUID' };

  this.assert(_.isUuid(this.obj));
});

answered Jan 08 '16 at 19:14

den bardadym

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Nice! Thanks. Should.js docs didn't leave any indication that this would be the way to do it... – brandonscript Jan 08 '16 at 19:19
Yep, probably. I will try to fix this later. – den bardadym Jan 08 '16 at 19:19

Extending should.js with a custom function

1 Answers1