Bug 1950076 [wpt PR 50903] - [functions] Parameters with defaults need not be trailing (WPT), a=testonly

Automatic update from web-platform-tests
[functions] Parameters with defaults need not be trailing (WPT)

It's syntactically valid to define a function where a parameter without
a default appears after a parameter with a default, for example:

  function --foo(--x:1px, --y, --z:2px) { ... }

There is currently no way to actually invoke such a function while
making use of the non-trailing defaults, but apparently this may change
in the future if we rework how IACVT works for arguments.
Invoking --foo(var(--unknown), 42px) would make the containing
declaration invalid at computed-value time, but in the future
the argument may "capture" this invalid state, and instead trigger
the default.

Bug: 389974127
Change-Id: I8d7c41bde2401ac89ec0a011f098e6051772f7b6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6281007
Commit-Queue: Anders Hartvoll Ruud <andruudchromium.org>
Reviewed-by: Steinar H Gunderson <sessechromium.org>
Cr-Commit-Position: refs/heads/main{#1423827}

--

wpt-commits: f2615dc6260757b8eb634d19383184031c6e7022
wpt-pr: 50903

UltraBlame original commit: 1fd66911aa07c7e6cbb708fc169e84919364c079

Author: marco-c

testing/web-platform/tests/css/css-mixins/at-function-parsing.html

@@ -909,6 +909,71 @@
 ;
 /
 /
+A
+parameter
+without
+a
+default
+may
+appear
+after
+a
+parameter
+with
+/
+/
+a
+default
+even
+though
+there
+'
+s
+no
+way
+to
+actually
+call
+-
+-
+foo
+(
+)
+/
+/
+with
+just
+-
+-
+y
+:
+test_valid_prelude
+(
+'
+function
+-
+-
+foo
+(
+-
+-
+x
+:
+1px
+-
+-
+y
+-
+-
+z
+:
+2px
+)
+'
+)
+;
+/
+/
 The
 value
 does

testing/web-platform/tests/css/css-mixins/dashed-function-eval.html

@@ -3985,6 +3985,116 @@
 template
 >
 <
+template
+data
+-
+name
+=
+"
+Unknown
+var
+(
+)
+in
+argument
+makes
+declaration
+IACVT
+"
+>
+<
+!
+-
+-
+Note
+:
+In
+the
+future
+this
+may
+be
+changed
+to
+instead
+trigger
+the
+default
+for
+-
+-
+x
+.
+-
+-
+>
+<
+style
+>
+function
+-
+-
+f
+(
+-
+-
+x
+:
+1px
+)
+{
+result
+:
+var
+(
+-
+-
+x
+)
+;
+}
+#
+target
+{
+-
+-
+actual
+:
+-
+-
+f
+(
+var
+(
+-
+-
+unknown
+)
+)
+;
+/
+*
+-
+-
+expected
+:
+<
+guaranteed
+-
+invalid
+>
+*
+/
+}
+<
+/
+style
+>
+<
+/
+template
+>
+<
 !
 -
 -