Problems with `hasAttr()`

Hi, I have been recently writing unit tests using avoriaz. There were a few problems with hasAttr(), for example:

var wrapper = mount(VueComponent)
// I'd like to check if `wrapper` has an attribute called `some-attr`,
// and don't care about what its value is.
expect(wrapper.hasAttr('some-attr')).toBe(true)
// But avoriaz requries a second argument:
// => Error: wrapper.hasAttribute() must be passed value as a string
// If the attribute value is variable then `hasAttr()` is likely to be unusable.

Further more, hasAttr() is not ideal for error report:

var wrapper = mount(VueComponent)
expect(wrapper.hasAttr('some-attr', 'some-value')).toBe(true)
// If the actual value is something other than expected,
// then the error message gives no idea about what actually happens:
// => Error: Expected false to be true.

I think it would make debugging much easier if the API looks like this:

var wrapper = mount(VueComponent)
// Checks for existence of the attribute:
expect(wrapper.hasAttr('some-attr')).toBe(true) 
// Checks for value identity:
expect(wrapper.getAttr('some-attr')).toBe('some-value')
// If the actual value is not as expected, then the error message maybe look like this:
// => Error: Expected 'not-some-value' to be 'some-value'. 

[eddyerburgh]

Yeah I agree ☺

I’ll add these methods this week and release in 4.0.0

[eddyerburgh]

I thought it should be the prop value of a vue instance