Polyfilled test selector optimizations

[izelnakri]

• In the first commit we introduce a polyfill for ie11 to support Array.from and Array.prototype.find.
• In the second commit we optimize findAll() and waitFor to use Array.from
• In the third commit we optimize triggerKeyEvent to use array.find() instead of array.filter(predicate)[0];

[scalvert]

Thanks, @izelnakri. Would you mind rebasing/resolving conflicts?

[izelnakri]

@scalvert rebased 👍

[scalvert]

Thanks! One thing I like better about this approach than the first PRs is that once we eventually drop support for IE11, we can just delete the polyfills.

[rwjblue]

I worry a little bit about automatically polyfilling these array methods. If a consuming app that intends to support IE11 adds some usage in their app of [].find (for example) the tests will pass (even if they are testing against IE11) but when deployed the app will throw/fail.

🤔

[izelnakri]

This is a good point i think but bit rare case. We could make them exported find() and/or toArray() from the same module name, thats an option. Solves both issues, what do you think @rwjblue?

export function find(array, func) {
  return array?.find?.(func) || findFunction(array, func);
  // or:
  return Array.prototype.find ? array.find(func) : findFunction(array, func); // this is probably more performant / i like this more
}

export function toArray(array, func) {

}

[rwjblue]

Ya, that seems good to me @izelnakri. Thank you!

[izelnakri]

@rwjblue updated the changes.

In the CI tests are passing, however for other CI actions there is a weird broccoli specific error that I couldn't understand. It doesn't seem to be related to the changes, would appreciate if you take a look: https://github.com/emberjs/ember-test-helpers/pull/949/checks?check_run_id=1542886060#step:5:121

[scalvert]

@izelnakri this was a bug in ember-auto-import if I'm not mistaken. I think there's been a fix that's shipped already. It looks like it was released in 1.9.0 of that package.

[scalvert]

@izelnakri if you rebase this branch onto master I think you should be g2g.

[izelnakri]

@scalvert done, thanks!

[rwjblue]

Awesome, thanks for working through this @izelnakri!