Stubbing a class method with Sinon.js

Question

I am trying to stub a method using sinon.js but I get the following error:

Uncaught TypeError: Attempted to wrap undefined property sample_pressure as function

Answer 1

I ran into the same error trying to mock a method of a CoffeeScript class using Sinon.

Given a class like this:

class MyClass
  myMethod: ->
    # do stuff ...

You can replace its method with a spy this way:

mySpy = sinon.spy(MyClass.prototype, "myMethod")

# ...

assert.ok(mySpy.called)

Just replace spy with stub or mock as needed.

Note that you'll need to replace assert.ok with whatever assertion your testing framework has.