LANG env variable needed for proper Rufo formatting

[pmk1c]

Your environment

• vscode-ruby version: 0.23.0
• Ruby version: 2.4.6
• Ruby version manager (if any): asdf
• VS Code version: 1.35.1
• Operating System: Fedora Linux
• Using language server? (eg useLanguageServer is true?) yes

Expected behavior

Formatting Ruby files with rufo as formatter should work if the file contains multibyte utf8 characters like "“”"

Actual behavior

It gives an error:

Format: executing rufo --filename=/path/to/file.rb -x...
[Error - 11:12:15] Request textDocument/formatting failed.
  Message: Request textDocument/formatting failed with message: 
    unable to execute rufo --filename=/path/to/file.rb -x:
    Error: Failed with exit code: 1 - unknown error
  Code: -32603 

When running Rufo with the same arguments in the command line on the file content, it works:

cat /path/to/file.rb | rufo --filename=/path/to/file.rb -x

When running the same command with the LANG env variable unset an error occurs:

LANG= cat /path/to/file.rb | rufo --filename=/path/to/file.rb -x
# Error: ./path/to/file.rb has syntax errors

So the reason seems to be, that the LANG environment variable is not set to something with utf8 support like C.UTF-8.

[minkir014]

I think it's problem with environment not the extension.

[pmk1c]

Since my environment declares LANG, I think this is a problem with the language server.
I understood this code as if there was some kind of ENV Whitelist? https://github.com/rubyide/vscode-ruby/blob/master/client/src/util/env.ts#L82
But I may be wrong…

[minkir014]

You must add arguments that set LANG variable that may work

[pmk1c]

I changed the extension's code to see if my guesses were true. And it did help solve the issue for me.

So here's the PR: #494

I don't see a reason not to pass the host's LANG env variable along. So I think this should be a quite unobtrusive change.

[wingrunr21]

Yes, that's an ENV whitelist. It's there to demonstrate I'm not pulling in potentially sensitive variables (like AWS_ stuff).