[at-function-parsing.html]
  [@function --foo() is valid]
    expected: FAIL

  [@function --foo( ) is valid]
    expected: FAIL

  [@function --foo(--x) is valid]
    expected: FAIL

  [@function --foo( --x ) is valid]
    expected: FAIL

  [@function --foo(--x auto) is valid]
    expected: FAIL

  [@function --foo(--x <angle>) is valid]
    expected: FAIL

  [@function --foo(--x <color>) is valid]
    expected: FAIL

  [@function --foo(--x <custom-ident>) is valid]
    expected: FAIL

  [@function --foo(--x <image>) is valid]
    expected: FAIL

  [@function --foo(--x <integer>) is valid]
    expected: FAIL

  [@function --foo(--x <length>) is valid]
    expected: FAIL

  [@function --foo(--x <length-percentage>) is valid]
    expected: FAIL

  [@function --foo(--x <number>) is valid]
    expected: FAIL

  [@function --foo(--x <percentage>) is valid]
    expected: FAIL

  [@function --foo(--x <resolution>) is valid]
    expected: FAIL

  [@function --foo(--x <string>) is valid]
    expected: FAIL

  [@function --foo(--x <time>) is valid]
    expected: FAIL

  [@function --foo(--x <url>) is valid]
    expected: FAIL

  [@function --foo(--x <transform-function>) is valid]
    expected: FAIL

  [@function --foo(--x <transform-list>) is valid]
    expected: FAIL

  [@function --foo(--x type(auto)) is valid]
    expected: FAIL

  [@function --foo(--x type(<length>)) is valid]
    expected: FAIL

  [@function --foo(--x type(<length> | auto)) is valid]
    expected: FAIL

  [@function --foo(--x type(none | auto)) is valid]
    expected: FAIL

  [@function --foo(--x type(*)) is valid]
    expected: FAIL

  [@function --foo(--x, --y) is valid]
    expected: FAIL

  [@function --foo(--x, --y, --z) is valid]
    expected: FAIL

  [@function --foo(--x <length>, --y, --z) is valid]
    expected: FAIL

  [@function --foo(--x, --y <number>, --z <angle>) is valid]
    expected: FAIL

  [@function --foo(--x : 10px) is valid]
    expected: FAIL

  [@function --foo(--x <length>: 10px) is valid]
    expected: FAIL

  [@function --foo(--x <length>: 10px, --y) is valid]
    expected: FAIL

  [@function --foo(--x, --y <length>: 10px) is valid]
    expected: FAIL

  [@function --foo(--x type(<length> | auto): auto) is valid]
    expected: FAIL

  [@function --foo(--x type(<length> | auto) : auto) is valid]
    expected: FAIL

  [@function --foo(--x <angle>: 10px) is valid]
    expected: FAIL

  [@function --foo(--x <length>#) is valid]
    expected: FAIL

  [@function --foo(--x <length>+) is valid]
    expected: FAIL

  [@function --foo(--x type(<length>+)) is valid]
    expected: FAIL

  [@function --foo(--x <transform-function>#) is valid]
    expected: FAIL

  [@function --foo(--x <transform-function>+) is valid]
    expected: FAIL

  [@function --foo(--x) returns type(*) is valid]
    expected: FAIL

  [@function --foo(--x) returns <length> is valid]
    expected: FAIL

  [@function --foo(--x) returns <length>+ is valid]
    expected: FAIL

  [@function --foo(--x) returns type(<length>) is valid]
    expected: FAIL

  [@function --foo(--x) returns type(<length> | auto) is valid]
    expected: FAIL

  [@function --foo(--x) returns type(foo | bar) is valid]
    expected: FAIL

  [@function --foo(--x:1px, --y, --z:2px) is valid]
    expected: FAIL