Improved lambda argument handling

syntax/javascript.vim

@@ -195,10 +195,10 @@ endif "DOM/HTML/CSS
 syntax cluster jsExpression contains=jsComment,jsLineComment,jsBlockComment,jsTaggedTemplate,jsTemplateString,jsStringD,jsStringS,jsRegexpString,jsNumber,jsFloat,jsThis,jsStatic,jsSuper,jsOperator,jsBooleanTrue,jsBooleanFalse,jsNull,jsFunction,jsArrowFunction,jsGlobalObjects,jsExceptions,jsFutureKeys,jsDomErrNo,jsDomNodeConsts,jsHtmlEvents,jsDotNotation,jsBracket,jsParen,jsBlock,jsFuncCall,jsUndefined,jsNan,jsKeyword,jsStorageClass,jsPrototype,jsBuiltins,jsNoise,jsCommonJS,jsAssignmentExpr,jsImportContainer,jsExportContainer,jsArgsObj,jsDecorator,jsAsyncKeyword,jsClassDefinition,jsArrowFunction,jsArrowFuncArgs
 syntax cluster jsAll        contains=@jsExpression,jsLabel,jsConditional,jsRepeat,jsReturn,jsStatement,jsTernaryIf,jsException
 syntax region  jsBracket    matchgroup=jsBrackets     start="\[" end="\]" contains=@jsAll,jsParensErrB,jsParensErrC,jsBracket,jsParen,jsBlock,@htmlPreproc fold
-syntax region  jsParen      matchgroup=jsParens       start="("  end=")"  contains=@jsAll,jsOf,jsParensErrA,jsParensErrC,jsParen,jsBracket,jsBlock,@htmlPreproc fold
+syntax region  jsParen      matchgroup=jsParens       start="("  end=")"  contains=@jsAll,jsOf,jsParensErrA,jsParensErrC,jsParen,jsBracket,jsBlock,@htmlPreproc fold extend
 syntax region  jsClassBlock matchgroup=jsClassBraces  start="{"  end="}"  contains=jsFuncName,jsClassMethodDefinitions,jsOperator,jsArrowFunction,jsArrowFuncArgs,jsComment,jsBlockComment,jsLineComment contained fold
-syntax region  jsFuncBlock  matchgroup=jsFuncBraces   start="{"  end="}"  contains=@jsAll,jsParensErrA,jsParensErrB,jsParen,jsBracket,jsBlock,@htmlPreproc,jsClassDefinition fold
-syntax region  jsBlock      matchgroup=jsBraces       start="{"  end="}"  contains=@jsAll,jsParensErrA,jsParensErrB,jsParen,jsBracket,jsBlock,jsObjectKey,@htmlPreproc,jsClassDefinition fold
+syntax region  jsFuncBlock  matchgroup=jsFuncBraces   start="{"  end="}"  contains=@jsAll,jsParensErrA,jsParensErrB,jsParen,jsBracket,jsBlock,@htmlPreproc,jsClassDefinition fold extend
+syntax region  jsBlock      matchgroup=jsBraces       start="{"  end="}"  contains=@jsAll,jsParensErrA,jsParensErrB,jsParen,jsBracket,jsBlock,jsObjectKey,@htmlPreproc,jsClassDefinition fold extend
 syntax region  jsTernaryIf  matchgroup=jsTernaryIfOperator start=+?+  end=+:+  contains=@jsExpression,jsTernaryIf
 
 "" catch errors caused by wrong parenthesis
@@ -213,21 +213,21 @@ if main_syntax == "javascript"
   syntax sync match jsHighlight grouphere jsBlock /{/
 endif
 
+syntax match   jsFuncArgDestructuring contained /\({\|}\|=\|:\|\[\|\]\)/ extend
 exe 'syntax match jsFunction /\<function\>/ nextgroup=jsGenerator,jsFuncName,jsFuncArgs skipwhite '.(exists('g:javascript_conceal_function') ? 'conceal cchar='.g:javascript_conceal_function : '')
 exe 'syntax match jsArrowFunction /=>/ skipwhite nextgroup=jsFuncBlock contains=jsFuncBraces '.(exists('g:javascript_conceal_arrow_function') ? 'conceal cchar='.g:javascript_conceal_arrow_function : '')
 
 syntax match   jsGenerator       contained '\*' nextgroup=jsFuncName,jsFuncArgs skipwhite
 syntax match   jsFuncName        contained /\<[a-zA-Z_$][0-9a-zA-Z_$]*/ nextgroup=jsFuncArgs skipwhite
-syntax region  jsFuncArgs        contained matchgroup=jsFuncParens start='(' end=')' contains=jsFuncArgCommas,jsFuncArgRest,jsComment,jsLineComment,jsStringS,jsStringD,jsNumber,jsFuncArgDestructuring nextgroup=jsFuncBlock keepend skipwhite skipempty
+syntax region  jsFuncArgs        contained matchgroup=jsFuncParens start='(' end=')' contains=jsFuncArgCommas,jsFuncArgRest,jsComment,jsLineComment,jsStringS,jsStringD,jsNumber,jsFuncArgDestructuring,jsArrowFunction,jsParen,jsArrowFuncArgs nextgroup=jsFuncBlock keepend skipwhite skipempty
 syntax match   jsFuncArgCommas   contained ','
 syntax match   jsFuncArgRest     contained /\%(\.\.\.[a-zA-Z_$][0-9a-zA-Z_$]*\))/ contains=jsFuncArgRestDots
 syntax match   jsFuncArgRestDots contained /\.\.\./
-syntax match   jsFuncArgDestructuring contained /\({\|}\|=\|:\|(\|)\|\[\|\]\)/ extend
 
 " Matches a single keyword argument with no parens
-syntax match   jsArrowFuncArgs  /\(\k\)\+\s*\(=>\)\@=/ skipwhite contains=jsFuncArgs nextgroup=jsArrowFunction
+syntax match   jsArrowFuncArgs  /\(\k\)\+\s*\(=>\)\@=/ skipwhite contains=jsFuncArgs nextgroup=jsArrowFunction extend
 " Matches a series of arguments surrounded in parens
-" syntax match   jsArrowFuncArgs  /(\%(.\)*)\s*\(=>\)\@=/ skipempty skipwhite contains=jsFuncArgs nextgroup=jsArrowFunction
+syntax match   jsArrowFuncArgs  /([^()]*)\s*\(=>\)\@=/ skipempty skipwhite contains=jsFuncArgs nextgroup=jsArrowFunction extend
 
 syntax keyword jsClassKeywords extends class contained
 syntax match   jsClassNoise /\./ contained