[Fix] do not be fooled by a function’s own toString method

Author: ljharb

index.js

@@ -12,6 +12,7 @@ var hasWeakSet = typeof WeakSet === 'function' && WeakSet.prototype;
 var weakSetHas = hasWeakSet ? WeakSet.prototype.has : null;
 var booleanValueOf = Boolean.prototype.valueOf;
 var objectToString = Object.prototype.toString;
+var functionToString = Function.prototype.toString;
 var match = String.prototype.match;
 var bigIntValueOf = typeof BigInt === 'function' ? BigInt.prototype.valueOf : null;
 
@@ -181,7 +182,7 @@ function toStr(obj) {
 
 function nameOf(f) {
     if (f.name) { return f.name; }
-    var m = match.call(f, /^function\s*([\w$]+)/);
+    var m = match.call(functionToString.call(f), /^function\s*([\w$]+)/);
     if (m) { return m[1]; }
     return null;
 }

test/fn.js

@@ -14,7 +14,7 @@ test('function name', function (t) {
     }());
     f.toString = function () { return 'function xxx () {}'; };
     var obj = [1, 2, f, 4];
-    t.equal(inspect(obj), '[ 1, 2, [Function: xxx], 4 ]');
+    t.equal(inspect(obj), '[ 1, 2, [Function (anonymous)], 4 ]');
 });
 
 test('anon function', function (t) {