Jest 21 Master Task

[cpojer]

• inline-requires for perf. cc @SimenB
• Rename jest-matchers to expect.
• Handle async errors: Handle async errors #4016
• Fix AppVeyor build
• Add displayName to MPR. Add displayName to MPR #4327
• Pretty format PRs

[SimenB]

I think the inline require one is best handled by people more familiar with Jest internals at the state it is. It works (the PR that is) by excluding a given module, but that's a slippery slope (and easy to break by messing with e.g. Array.prototype, although that's not new with a lazy Jest). Something should be done WRT ensuring the env in a test is unable to touch the runner's env.

Happy to help out though, of course!

(link: #3786)

And personally I'd like to see a solution for jest-matchers to work in IE10, not sure how high if a priority that is, though?

EDIT: I'm senile, Aaron already said what I said, only better.

i messed around with this issue this week. My opinion that we should make everything that is not a test execute in the outer VM scope.

EDIT2: #4340

[pedrottimark]

To finish the batch of work on pretty-format:

• merge Call same printChildren as for React in HTMLElement plugin #4275 and then 3 more small PR for HTMLElement plugin
• merge Add Usage in Jest to pretty-format/README.md #4253 and then 1 more large PR for pretty-format/README.md

While we are fixing edge cases with breaking changes:

• decide about trim method, and then merge Join lines with newline in jest-diff #4314 and its little brother Replace match with test and omit redundant String conversion in jest-diff #4311

But let #3429 marinate until following version of Jest:

• get feedback about the concept
• make sure it works with multi-line strings in backticks
• formats diff when snapshot test fails as similarly as possible

[rogeliog]

Do we need #4278 for Jest 21?

[cpojer]

@rogeliog I'm not sure, I think there is a ton of stuff we could do here to make the API better and unclear right now if we should touch it and make it a thing for 21 at all. Let's discuss in the jest-core channel.

[wtgtybhertgeghgtwtg]

Just making sure, but #4091 will land with jest@21 and friends, right?

[thymikee]

@wtgtybhertgeghgtwtg yup, it's already on master (from which the releases are cut)

[thymikee]

it's actually already on jest@test if you need it

[skovhus]

I think #4074 and browser support documentation.... : )

What about the failing CI? Does anybody have an update on that?

[cpojer]

CI is only failing on AppVeyor with a minor issue that nobody has spent time on fixing yet.

[excitement-engineer]

In the PR comments you mentioned that #3660 will land in Jest 21 as well. I finished up the PR as per your comments so hopefully it can be merged in time for Jest 21:)

[cpojer]

Yep, it's part of 21!

[rogeliog]

@cpojer #4379

[rogeliog]

Also, should we use a milestone for Jest 21?

[SimenB]

Usage in the browser also needs docs, and probably a full example