[Matcher]: toMatchSnapshot for enzyme comp

[blainekasten]

jest-enzyme ONLY

It would be real cool if we could support enzyme with snapshot testing in jest. Since we rejected it from living in the enzyme repo (enzymejs/enzyme#541), this seems like the natural place.

Of course we would have to fall back to the original toMatchSnapshot if a non-enzyme wrapper was given.

Basic thoughts:

var originalToMatchSnapshot;
toMatchSnapshot(enzymeWrapper) {
  if (notEnzyme(enzymeWrapper)) {
    return originalToMatchSnapshot(enzymeWrapper);
  }

  var snapshotable = convertToCompatibleJSON(enzymeWrapper);
  return originalToMatchSnapshot(snapshotable);
}

[blainekasten]

Looks like we could just use this: https://github.com/adriantoine/enzyme-to-json

[blainekasten]

Tried to implement this, seems like we probably need #44 first as I'm not getting the right class values set for my matcher that I need to get appropriate access to the original toMatchSnapshot matcher.

[blainekasten]

Next try #67