mocha: Cannot read property 'be' of undefined

Question

I'm writing unit test for my project. But I always meet this problem

Cannot read property 'be' of undefined.

I have a test suite called model-xxx, and I wanna try each method in this model. So each method I write a sub test suite in model-xxx. like this:

enter image description here

And each method is related with mongoose, so I hope these sub suite will be async. so each method I write done() in before and after and it

but none of these suite passed. error like this:

enter image description here

and like this:

Cannot read property 'not' of undefined.

why this occurs? does this mean something wrong with my should.js? but it doesn't make sense

hope for solutions.

Answer 1

Chai's should is a function that needs to be called before you can use should-style assertions:

var should = require('chai').should();

See the documentation.