function takes invalid variable names for --argument-names

[ammgws]

When running the following function,

function testscope
  set DEBUG 1

  function test1 --no-scope-shadowing --argument-names a b
    echo (status function)" debug=$DEBUG (args: $argv)"
  end

  function test2 --argument-names a b --no-scope-shadowing
    echo (status function)" debug=$DEBUG (args: $argv)"
  end

  function test3 --argument-names "a b" --no-scope-shadowing
    echo (status function)" debug=$DEBUG (args: $argv)"
  end

  set names "a b"
  function test4 --argument-names $names --no-scope-shadowing
    echo (status function)" debug=$DEBUG (args: $argv)"
  end

  test1 "foo" "bar"
  test2 "foo" "bar"
  test3 "foo" "bar"
  test4 "foo" "bar"
end

I get this output:

test1 debug=1 (args: foo bar)
test2 debug= (args: foo bar)
test3 debug=1 (args: foo bar)
test4 debug=1 (args: foo bar)

I take it this happens because REQUIRE_ORDER is used when parsing the flags here?

REQUIRE_ORDER means don't recognize them as options; stop option processing when the first non-option is seen. This is what Unix does. This mode of operation is selected by using `+' as the first character of the list of option characters.

Should this be documented in the docs for function, or does it go without saying?

[faho]

Well, no. This isn't using REQUIRE_ORDER specifically.

It's understanding --no-scope-shadowing as a name for a variable.

Which is awful because $--no-scope-shadowing can't be expanded as a variable (because - isn't actually valid in variable names!)

[faho]

Test-case:

function testfun --argument-names a b c --no-scope-shadowing
   set -l
end

Presumably this should error out.

[6A61736F6E206E61646572]

Cheers.

Just to check: REQUIRE_ORDER is needed so that NAME in function NAME [OPTIONS] keeps its position before OPTIONS, otherwise getopts will move to the end where it could become an arg to --argument-names if that was the last defined option?

// This command is atypical in using the "+" (REQUIRE_ORDER) option for flag parsing.
// This is needed due to the semantics of the -a/--argument-names flag.

This is what is confusing me, from here, assuming fish's getopts implementation is the same:

If require_order is enabled, options processing terminates when the first non-option is encountered.
--foo arg1 --bar arg2 arg3
is equivalent to
--foo -- arg1 --bar arg2 arg3

So with testfun --argument-names a b c --no-scope-shadowing, it would turn into
testfun --argument-names -- a b c --no-scope-shadowing where ARGV is "a", "b", "c", "--no-scope-shadowing`, but that's clearly not the case.. :/