npm and error messages

node_modules/util/node_modules/inherits/test.js

@@ -0,0 +1,25 @@
+var inherits = require('./inherits.js')
+var assert = require('assert')
+
+function test(c) {
+  assert(c.constructor === Child)
+  assert(c.constructor.super_ === Parent)
+  assert(Object.getPrototypeOf(c) === Child.prototype)
+  assert(Object.getPrototypeOf(Object.getPrototypeOf(c)) === Parent.prototype)
+  assert(c instanceof Child)
+  assert(c instanceof Parent)
+}
+
+function Child() {
+  Parent.call(this)
+  test(this)
+}
+
+function Parent() {}
+
+inherits(Child, Parent)
+
+var c = new Child
+test(c)
+
+console.log('ok')