runtime(javascript): Add "using" keyword to JavaScript syntax highlighting

Prior to this change, const and let were keywords for variable
declarations.

This change adds `using` as another keyword for variable declaration.

This JavaScript feature was recently introduced.

Docs:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/using

closes: #18381

Signed-off-by: Devin Weaver <suki@tritarget.org>
Signed-off-by: Christian Brabandt <cb@256bit.org>

diff --git a/runtime/syntax/javascript.vim b/runtime/syntax/javascript.vim
index cc900d88856a868d47e5b0cfd677f0a30f0177c5..c89fcedce62d5b754883ac5d02844e000c7df4d5 100644 (file)
--- a/runtime/syntax/javascript.vim
+++ b/runtime/syntax/javascript.vim
@@ -12,6 +12,7 @@
 "              2018 Apr 14: adjusted javaScriptRegexpString (LongJohnCoder)
 "              2024 Aug 14: fix a few stylistic issues (#15480)
 "              2025 Aug 07: as is a reserved keyword (#17912)
+"              2025 Sep 24: using is a reserved keyword (Devin Weaver)
 
 " tuning parameters:
 " unlet javaScript_fold
@@ -68,7 +69,7 @@ syn keyword javaScriptMessage         alert confirm prompt status
 syn keyword javaScriptGlobal           self window top parent
 syn keyword javaScriptMember           document event location
 syn keyword javaScriptDeprecated       escape unescape
-syn keyword javaScriptReserved         abstract as boolean byte char class const debugger double enum export extends final float from goto implements import int interface let long native package private protected public short super synchronized throws transient var volatile async
+syn keyword javaScriptReserved         abstract as boolean byte char class const debugger double enum export extends final float from goto implements import int interface let long native package private protected public short super synchronized throws transient var volatile async using
 syn keyword javaScriptModifier  static
 
 syn cluster  javaScriptEmbededExpr     contains=javaScriptBoolean,javaScriptNull,javaScriptIdentifier,javaScriptStringD,javaScriptStringS,javaScriptStringT