.env
env = sys.env
allows reading environment variables using plain indexing
assert.equals 'string', type env.HOME
assert.equals 'string', type env['HOME']
assert.equals os.getenv('HOME'), env.HOME
allows setting variables via assignment
env.MY_VAR = 'myval'
assert.equals 'myval', env.MY_VAR
assert.equals 'myval', os.getenv('MY_VAR')
allows unsetting variables using a nil assignment
env.MY_VAR = 'myval'
assert.equals 'myval', os.getenv('MY_VAR')
env.MY_VAR = nil
assert.is_nil env.MY_VAR
assert.is_nil os.getenv('MY_VAR')
allows iterating over the env using pairs
env.MY_VAR = 'yowser!'
as_table = {k,v for k,v in pairs env}
assert.equals 'yowser!', as_table.MY_VAR
find_executable(name, path)
returns the path of the executable found in Howl's PATH by default
found = sys.find_executable 'sh'
assert.is_not_nil found
assert.equals 'sh', howl.io.File(found).basename
returns nil when the executable is not found
assert.is_nil sys.find_executable 'howl-no-such-executable'
looks only in path when given
with_tmpdir (dir) ->
(dir / 'howl-tool').contents = ''
assert.equals (dir / 'howl-tool').path, sys.find_executable 'howl-tool', "/howl-none:#{dir.path}"
assert.is_nil sys.find_executable 'howl-tool'
assert.is_nil sys.find_executable 'sh', dir.path
