Fix global module executable path on Windows

[Daniel15]

Summary
Node.js is almost always installed in C:\Program Files\Yarn, which regular users can't write to. However, Yarn defaults to installing the executables for global modules in the Node directory. This means that the out-of-the-box experience for people installing global modules on Windows is totally broken.

It should instead place them in a directory that the user can write to. I'm going with %LocalAppData\Yarn\bin (eg. C:\Users\Daniel\AppData\Local\Yarn\bin) as it makes the most sense given all the config and cache is already in that directory. I also updated the path in the installer, as the path the installer was using didn't actually exist (.bin instead of bin).

Test plan

Tested bin\yarn global add webpack, it placed the files in the right directory:

Closes #3055

[DustinKingen]

Can confirm the additional if statement fixes the issue. Not sure whether changing .bin -> bin is a breaking change. I noticed that the .bin folder is not created after installing yarn. I had to manually add the folder to AppData\Local\Yarn. Yarn will need to ensure .bin or bin exists so that scripts installed with yarn global will be available on the path.

[Daniel15]

Not sure whether changing .bin -> bin is a breaking change

.bin never actually existed, so that should be fine.

[Daniel15]

Just realised this is broken for non-root users on Linux too... Need to fix that as well.

test@a5cf448820fd:/tmp/lol$ /yarn-src/bin/yarn global add create-react-app
yarn global v0.24.0-0
[1/4] Resolving packages...
[2/4] Fetching packages...
[3/4] Linking dependencies...
[4/4] Building fresh packages...
success Installed "[email protected]" with binaries:
      - create-react-app
error We don't have permissions to touch the file "/usr/bin/create-react-app".
info Visit https://yarnpkg.com/en/docs/cli/global for documentation about this command.

[gaearon]

Thanks for the fix.

[wtchangdm]

Sorry for asking question here, is the PATH environment variable added only when yarn was installed by Windows Installer and not by npm?

[Daniel15]

Yeah, that's right. We could probably also do it as a post install script, but it was much easier to do in the installer so we just have it there for now. Sent from my phone.

…

On May 27, 2017 4:41 AM, "W.T. Chang" ***@***.***> wrote: Sorry for asking question here, is the PATH environment variable added only when yarn was installed by Windows Installer and not by npm? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#3233 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAFnHaM7jFJCgpLk4wt_alzj4T9CsASiks5r9xzcgaJpZM4NFTcP> .