Improve JavaScript syntax inside curly brackets in the template

Author: leafOfTree

syntax/svelte-html.vim

@@ -36,13 +36,13 @@ syntax region svelteExpression
       \ start="{"
       \ end="}\(}\|;\)\@!"
 
-" Multiple lines expressions are supposed to end with '}}'
+" Multiple lines expressions are supposed to end with '}}' or ')}'
 syntax region svelteExpression 
       \ containedin=svelteValue,htmlValue,htmlAttr
       \ contains=@simpleJavascriptExpression
       \ matchgroup=svelteBrace
       \ start="{"
-      \ end="\(}\)\@<=}"
+      \ end="\(}\)\@<=}\|\()\)\@<=}"
 
 syntax region svelteExpression 
       \ containedin=htmlSvelteTemplate,svelteValue,htmlString,htmlArg,htmlTag,htmlAttr,htmlValue,htmlAttr
@@ -78,7 +78,7 @@ syntax region svelteBlockEnd
 syntax keyword svelteBlockKeyword if else each await then catch as
 
 syntax cluster simpleJavascriptExpression 
-      \ contains=javaScriptStringS,javaScriptStringD,javaScriptTemplateString,javascriptNumber,javaScriptOperator
+      \ contains=javaScript.*
 
 " Redefine JavaScript syntax
 syntax region javaScriptStringS	
@@ -92,13 +92,6 @@ syntax region javaScriptTemplateExpression
       \ matchgroup=Type
       \ start=+${+ end=+}+ keepend contained
 
-syntax match javaScriptNumber '\v<-?\d+L?>|0[xX][0-9a-fA-F]+>' contained
-syntax match javaScriptOperator '[-!|&+<>=%*~^]' contained
-syntax match javaScriptOperator '\v(*)@<!/(/|*)@!' contained
-syntax keyword javaScriptOperator contained
-      \ delete instanceof typeof void new in of const let var
-      \ return function
-
 highlight default link svelteAttr htmlTag
 if s:highlight_svelte_attr
   highlight default link svelteKey Type