chef

Chef::Mixin::ShellOut#shell_out_compact

PREFERRED APIS:

shell_out_compact and shell_out_compact! flatten their array arguments and remove nils and pass
the resultant array to shell_out.  this actually eliminates spaces-in-args bugs because this:

shell_out!("command #{arg}")

becomes two arguments if arg has spaces and requires quotations:

shell_out!("command '#{arg}'")

using shell_out_compact! this becomes:

shell_out_compact!("command", arg)

and spaces in the arg just works and it does not become two arguments (and the shell quoting around
the argument must actually be removed).

there's also an implicit join between all the array elements, and nested arrays are flattened which
means that odd where-do-i-put-the-spaces options handling just works, and instead of this:

   opts = ""                     # needs to be empty string for when foo and bar are both missing
   opts << " -foo" if needs_foo? # needs the leading space on both of these
   opts << " -bar" if needs_bar?
   shell_out!("cmd#{opts}")      # have to think way too hard about why there's no space here

becomes:

   opts = []
   opts << "-foo" if needs_foo?
   opts << "-bar" if needs_bar?
   shell_out_compact!("cmd", opts)

and opts can be an empty array or nil and it'll work out fine.

generally its best to use shell_out_compact! in code and setup expectations on shell_out! in tests

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