feat: support arrow functions in Function/#/to-tring-tokens.js

.lint

@@ -19,6 +19,7 @@ sub
 ./function/#/copy.js
 ./object/unserialize.js
 ./test/function/valid-function.js
+./test/function/#/to-string-tokens.js
 evil
 
 ./math/_pack-ieee754.js

function/#/to-string-tokens.js

@@ -1,11 +1,18 @@
 'use strict';
 
-var validFunction = require('../valid-function')
-
-var re = /^\s*function[\0-\'\)-\uffff]*\(([\0-\(\*-\uffff]*)\)\s*\{([\0-\uffff]*)\}\s*$/;
+var validFunction = require('../valid-function');
 
+var re1 = /^\s*function[\0-\'\)-\uffff]*\(([\0-\(\*-\uffff]*)\)\s*\{([\0-\uffff]*)\}\s*$/
+  , re2 = /^\s*\(?([\0-\'\*-\uffff]*)\)?\s*=>\s*(\{?[\0-\uffff]*\}?)\s*$/;
 
 module.exports = function () {
-	var data = String(validFunction(this)).match(re);
+	var str = String(validFunction(this))
+	  , data = str.match(re1);
+	if (!data) {
+		data = str.match(re2);
+		if (!data) throw new Error("Unrecognized string format");
+		data[1] = data[1].trim();
+		if (data[2][0] === '{') data[2] = data[2].trim().slice(1, -1);
+	}
 	return { args: data[1], body: data[2] };
 };

test/function/#/to-string-tokens.js

@@ -9,4 +9,16 @@ module.exports = function (t, a) {
 		{ args: 'raz', body: '' });
 	a.deep(t.call(function () { Object(); }),
 		{ args: '', body: ' Object(); ' });
+
+	try {
+		eval("(() => {})");
+	} catch (e) {
+		// Non ES2015 env
+		return;
+	}
+
+	a.deep(t.call(eval("(() => {})")), { args: '', body: '' });
+	a.deep(t.call(eval("((elo) => foo)")), { args: 'elo', body: 'foo' });
+	a.deep(t.call(eval("(elo => foo)")), { args: 'elo', body: 'foo' });
+	a.deep(t.call(eval("((elo, bar) => foo())")), { args: 'elo, bar', body: 'foo()' });
 };