toHaveClass should wrap existing matcher

[jcarlson]

My test suite already has a custom matcher called toHaveClass (and also toNotHaveClass). So expect-enzyme clashes with this existing matcher and breaks tests which are expecting the non-enzymified version of the matcher.

Looks like it should be trivial to addEnzymeSupport to resolve this...

[PsychoLlama]

Hey @jcarlson! Sorry things are breaking. You're right, it should check for an existing method before registering a new one. What type of value is .toHaveClass expecting on your side?

[jcarlson]

My matchers are expecting a node and a string to assert that the node has that class. Such as:

class MyComponent extends Component {
  render () {
    return <div className='my-component'>Hello!</div>
  }
}

let rendered = ReactDOM.render(<MyComponent />, document.createElement('div'))
let node = ReactDOM.findDOMNode(rendered)
expect(node).toHaveClass('my-component')

Here's my matchers:

expect.extend({
  toHaveClass (className) {
    expect.assert(
      this.actual.classList ?
        this.actual.classList.contains(className) :
        false,
      'Expected class list %s to contain  %s.',
      this.actual.classList ?
        Array.from(this.actual.classList) :
        '(not a DOM element)',
      className
    )
    return this
  },

  toNotHaveClass (className) {
    expect.assert(
      this.actual.classList ?
        !this.actual.classList.contains(className) :
        true,
      'Expected class list %s to not contain  %s.',
      this.actual.classList ?
        Array.from(this.actual.classList) :
        '(not a DOM element)',
      className
    )
    return this
  }
})

[PsychoLlama]

Sweet, thanks!
I'm hoping to add a few new features this weekend, I'll be sure to prioritize this.

[PsychoLlama]

I've just pushed out v0.13.2 which should resolve your issue. Just be sure you import (and extend) your custom assertions before loading expect-enzyme. I'm closing this issue for now, but feel free to re-open if you need!