get-function with underscore in function name fails with "Function not found"

[znck]

Demo: https://repl.it/repls/TanHeavyNonlinearprogramming

I tried to write test but dart is beyond me.

[lunelson]

I just hit this too. Took me a while to track it down, seems to have come up in a recent patch.

Sass' internal re-mapping of _ to - on function and variable-names was known to me, but I'd never seen it pose a problem WRT function lookup before. The following code works in libsass and worked in dart-sass as of 1.22.0, but now fails without any clues as to the reason (Error: Function not found: test_fn).

Note that if I assign $test-fn: get-function('test-fn');, replacing the _ with - myself, it works.

@function test_fn($args...) { @return $args; }

$test-fn: get-function('test_fn');

.test {
  output: call($test-fn, foo, bar);
}

/* libsass only */
.test {
  output: foo, bar;
}