[Tests] cover util.inspect.custom

.nycrc

@@ -3,7 +3,7 @@
   "check-coverage": true,
   "instrumentation": false,
   "sourceMap": false,
-  "reporter": "html",
+  "reporter": ["html", "text-summary"],
   "lines": 94,
   "statements": 94,
   "functions": 96,

test/inspect.js

@@ -1,8 +1,20 @@
-var inspect = require('../');
 var test = require('tape');
+var hasSymbols = require('has-symbols')();
+var utilInspect = require('../util.inspect');
+
+var inspect = require('..');
 
 test('inspect', function (t) {
     t.plan(1);
     var obj = [{ inspect: function () { return '!XYZ¡'; } }, []];
     t.equal(inspect(obj), '[ !XYZ¡, [] ]');
 });
+
+test('inspect custom symbol', { skip: !hasSymbols || !utilInspect }, function (t) {
+	t.plan(1);
+
+	var obj = { inspect: function () { return 'string'; } };
+	obj[utilInspect.custom] = function () { return 'symbol'; };
+
+	t.equal(inspect([obj, []]), '[ ' + (utilInspect.custom ? 'symbol' : 'string') + ', [] ]');
+});