Yarn + Create React App Umbrella

[gaearon]

We shipped Yarn integration but there are a few small annoyances.
I'd like to consolidate them.

When they are fixed I'll feel comfortable recommending Yarn to CRA users more broadly.

• It looks like yarn@0.18 was released with latest tag for some time since it started failing our CI (Fix end-to-end test on Yarn #1167). I'm happy to help test Yarn by opting into using next builds on CI, but I want to make sure we have a process in place that Yarn RC releases don't become latest until they're well tested.
• In 0.18 (unstable), missing deps v0.18.0 postinstall missing dependencies yarnpkg/yarn#2142
• Not working with Heroku buildpack Building app does not work with yarn mars/create-react-app-buildpack#23
• Huge size on disk [feature] hint hoister algorithm yarnpkg/yarn#2306 https://twitter.com/nicdex/status/818606636919095296
• peerDependencies warning has a false positive Unmet peer dependency warning when the peer dependency is installed at the same time yarnpkg/yarn#2132
• Offline installation doesn't work Provide a way to fallback to cached version when installing latest offline yarnpkg/yarn#2225
• Yarn might not be installing binary dependencies (such as fsevents) Error in jest watch when using yarn for dependency installation #1474, Question: react-scripts start constantly @ 30% CPU #1670
• Global binaries reportedly don't get linked yarn global add doesn't install binaries properly yarnpkg/yarn#648, reported in Added option to disable yarn on initial build to fix jest failure #1370
• Local binaries get deleted react-scripts binary is disappeared #1439
• yarn global add doesn't work on Windows When installing global modules, Yarn tries to create .cmd file in wrong directory yarnpkg/yarn#2192
• yarn global add doesn't work with nvm "yarn global add" doesn't globally install packages if .yarn-cache was restored yarnpkg/yarn#1151 (comment)
• issues with flaky connections Doesn't work well on a flaky connection yarnpkg/yarn#746, Cannot install packages from github when offline yarnpkg/yarn#1925

[Daniel15]

I want to make sure we have a process in place that Yarn RC releases don't become latest until they're well tested.

This is tracked in yarnpkg/yarn#2161.

[ffxsam]

This issue I posted might be related:
yarnpkg/yarn#2229

I was excited to start using it with my Meteor projects, but went back to npm as I don't find yarn to be all that reliable.

[gaearon]

Also interesting: apparently installed size is larger with Yarn? https://twitter.com/petrhurtak/status/812356423795568640

[gaearon]

Apparently the disk size issue is very bad.
https://twitter.com/nicdex/status/818606636919095296

[Daniel15]

The disk size issue might be related to yarnpkg/yarn#2306. It'd be worth opening an issue on the Yarn GitHub project to track it.

[gaearon]

Another issue report related to binaries: #1370.
Not sure if diagnosis is correct.

[Timer]

-snip- yarnpkg/yarn#2649

[gaearon]

@Timer Mind filing a Yarn bug?

[Timer]

Filed. 😄

[fson]

Unmet peer dependency warning (yarnpkg/yarn#2132) has been fixed in Yarn 0.22.0.

[dannylewis-sheffield]

With regard to "issues with flaky connections" I've added the following comment on yarnpkg/yarn#746

OK I had the same issues when building create-react-app inside docker, never managed to install.

Backed out one step to the vagrant box, running on VirtualBox, installed node yarn etc and then again ran create-react-app. Same issue but it did get further, downloaded more packages, than under docker.

Changed the network settings on vagrant from NAT to Bridged:

Old:
config.vm.network :forwarded_port, guest: 80, host: 1026, auto_correct: true

New:
config.vm.network :public_network, :public_network => "wlan0"

You can switch back the configs once you have successfully done what you needed to.

Ran create-react-app again and it looked like it it would complete, despite the odd "warning There appears to be trouble with your network connection. Retrying..." Nope failed on ESOCKETTIMEDOUT, but just about there!

Ran it again, success!

Back to docker version, long story short it eventually successfully built. Good job I'm doing intermediate builds...

Networks can be flaky, some more than others.

I would like to see the following be able to be set in yarn config:

download_max_retry - does what it says on the tin and defaults to 20
download_clear_failed_count_on_success - true or false, default false, if true would reset the failed download count to 0 on the next successful download, this would mean it would only fail to complete if it failed to download the last file in the queue (assuming downloads are parallel, some fail and are then put back in the queue)

Hope this helps and thanks for the tools!

[gaearon]

Seems like this is as good as it gets for now.