JavaScript: Better highlighting of functions

components/prism-javascript.js

@@ -2,7 +2,7 @@ Prism.languages.javascript = Prism.languages.extend('clike', {
 	'keyword': /\b(as|async|await|break|case|catch|class|const|continue|debugger|default|delete|do|else|enum|export|extends|finally|for|from|function|get|if|implements|import|in|instanceof|interface|let|new|null|of|package|private|protected|public|return|set|static|super|switch|this|throw|try|typeof|var|void|while|with|yield)\b/,
 	'number': /\b-?(0[xX][\dA-Fa-f]+|0[bB][01]+|0[oO][0-7]+|\d*\.?\d+([Ee][+-]?\d+)?|NaN|Infinity)\b/,
 	// Allow for all non-ASCII characters (See http://stackoverflow.com/a/2008444)
-	'function': /[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*(?=\()/i,
+	'function': /[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*(?=\s*\()/i,
 	'operator': /-[-=]?|\+[+=]?|!=?=?|<<?=?|>>?>?=?|=(?:==?|>)?|&[&=]?|\|[|=]?|\*\*?=?|\/=?|~|\^=?|%=?|\?|\.{3}/
 });
 
@@ -11,6 +11,11 @@ Prism.languages.insertBefore('javascript', 'keyword', {
 		pattern: /(^|[^/])\/(?!\/)(\[[^\]\r\n]+]|\\.|[^/\\\[\r\n])+\/[gimyu]{0,5}(?=\s*($|[\r\n,.;})]))/,
 		lookbehind: true,
 		greedy: true
+	},
+	// This must be declared before keyword because we use "function" inside the look-forward
+	'function-variable': {
+		pattern: /[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*(?=\s*=\s*(?:function\b|(?:\([^()]*\)|[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*)\s*=>))/i,
+		alias: 'function'
 	}
 });
 

prism.js

@@ -692,7 +692,7 @@ Prism.languages.javascript = Prism.languages.extend('clike', {
 	'keyword': /\b(as|async|await|break|case|catch|class|const|continue|debugger|default|delete|do|else|enum|export|extends|finally|for|from|function|get|if|implements|import|in|instanceof|interface|let|new|null|of|package|private|protected|public|return|set|static|super|switch|this|throw|try|typeof|var|void|while|with|yield)\b/,
 	'number': /\b-?(0[xX][\dA-Fa-f]+|0[bB][01]+|0[oO][0-7]+|\d*\.?\d+([Ee][+-]?\d+)?|NaN|Infinity)\b/,
 	// Allow for all non-ASCII characters (See http://stackoverflow.com/a/2008444)
-	'function': /[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*(?=\()/i,
+	'function': /[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*(?=\s*\()/i,
 	'operator': /-[-=]?|\+[+=]?|!=?=?|<<?=?|>>?>?=?|=(?:==?|>)?|&[&=]?|\|[|=]?|\*\*?=?|\/=?|~|\^=?|%=?|\?|\.{3}/
 });
 
@@ -701,6 +701,11 @@ Prism.languages.insertBefore('javascript', 'keyword', {
 		pattern: /(^|[^/])\/(?!\/)(\[[^\]\r\n]+]|\\.|[^/\\\[\r\n])+\/[gimyu]{0,5}(?=\s*($|[\r\n,.;})]))/,
 		lookbehind: true,
 		greedy: true
+	},
+	// This must be declared before keyword because we use "function" inside the look-forward
+	'function-variable': {
+		pattern: /[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*(?=\s*=\s*(?:function\b|(?:\([^()]*\)|[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*)\s*=>))/i,
+		alias: 'function'
 	}
 });
 

tests/languages/javascript/function-variable_feature.test

@@ -0,0 +1,24 @@
+foo = function () {}
+bar = function baz () {}
+fooBar = x => x
+ಠ_ಠ = () => {}
+Ƞȡ_҇ = (ಠ, Ƞ = 2) => {}
+
+----------------------------------------------------
+
+[
+	["function-variable", "foo"], ["operator", "="], ["keyword", "function"],
+	["punctuation", "("], ["punctuation", ")"], ["punctuation", "{"], ["punctuation", "}"],
+	["function-variable", "bar"], ["operator", "="], ["keyword", "function"], ["function", "baz"],
+	["punctuation", "("], ["punctuation", ")"], ["punctuation", "{"], ["punctuation", "}"],
+	["function-variable", "fooBar"], ["operator", "="], " x ", ["operator", "=>"], " x\r\n",
+	["function-variable", "ಠ_ಠ"], ["operator", "="], ["punctuation", "("], ["punctuation", ")"],
+	["operator", "=>"], ["punctuation", "{"], ["punctuation", "}"],
+	["function-variable", "Ƞȡ_҇"], ["operator", "="],
+	["punctuation", "("], "ಠ", ["punctuation", ","], " Ƞ ", ["operator", "="], ["number", "2"], ["punctuation", ")"],
+	["operator", "=>"], ["punctuation", "{"], ["punctuation", "}"]
+]
+
+----------------------------------------------------
+
+Checks for variables obviously containing functions.

tests/languages/javascript/function_feature.test

@@ -1,5 +1,7 @@
 foo()
+foo ()
 foo_bar()
+foo_bar ( )
 f42()
 _()
 $()
@@ -10,6 +12,8 @@ $()
 
 [
 	["function", "foo"], ["punctuation", "("], ["punctuation", ")"],
+	["function", "foo"], ["punctuation", "("], ["punctuation", ")"],
+	["function", "foo_bar"], ["punctuation", "("], ["punctuation", ")"],
 	["function", "foo_bar"], ["punctuation", "("], ["punctuation", ")"],
 	["function", "f42"], ["punctuation", "("], ["punctuation", ")"],
 	["function", "_"], ["punctuation", "("], ["punctuation", ")"],