Bun runtime fails if there's an .env file in the working directory

[Burgestrand]

Hi!

When there's an .env in the working directory of Bun, the Bun runtime crashes with a JSON parse error.

I believe the reason for the crash is because Bun outputs [0.32ms] ".env" to STDERR when it loads the .env-file, and the bun runner (or external runtime?) combines STDERR with STDOUT into a single output value, which is then parsed with JSON.parse.

It seems the external runtime merges STDERR on purpose:

execjs/lib/execjs/external_runtime.rb

Line 210 in 6c1c228

io = IO.popen(binary.split(' ') << filename, **(@popen_options.merge({err: [:child, :out]})))

Reproduction steps

This is reproducible on master.

require "bundler/setup"
require "execjs"

ExecJS.runtime = ExecJS::Runtimes::Bun

Dir.mktmpdir do |dir|
  Dir.chdir(dir)

  # Works fine.
  $stdout.puts ExecJS.eval("1+1")

  # Crashes with JSON parse error.
  File.write(".env", "FOO=BAR")
  $stdout.puts ExecJS.eval("1+1")
end

Result:

2
/Users/kim/.asdf/installs/ruby/3.1.2/lib/ruby/3.1.0/json/common.rb:216:in `parse': 451: unexpected token at 'ms] ".env" (JSON::ParserError)
["ok"]'
        from /Users/kim/.asdf/installs/ruby/3.1.2/lib/ruby/3.1.0/json/common.rb:216:in `parse'
        from /Users/kim/Projects/execjs/lib/execjs/external_runtime.rb:69:in `extract_result'
        from /Users/kim/Projects/execjs/lib/execjs/external_runtime.rb:40:in `exec'
        from /Users/kim/Projects/execjs/lib/execjs/external_runtime.rb:15:in `initialize'
        from /Users/kim/Projects/execjs/lib/execjs/runtime.rb:68:in `new'
        from /Users/kim/Projects/execjs/lib/execjs/runtime.rb:68:in `compile'
        from /Users/kim/Projects/execjs/lib/execjs/runtime.rb:55:in `eval'
        from /Users/kim/Projects/execjs/lib/execjs/module.rb:23:in `eval'
        from example.rb:14:in `block in <main>'
        from /Users/kim/.asdf/installs/ruby/3.1.2/lib/ruby/3.1.0/tmpdir.rb:96:in `mktmpdir'
        from example.rb:6:in `<main>'

[casperisfine]

FYI: @terracatta

[byroot]

Fixed in 2.9.1