Have you seen the test fail? I am very confident the error message is rather unhelpful (something along the line "expected false to be true").

Better ways of expressing the assertion:

```js
var sharedMethodNames = // select names from object.methods()

// be strict - this will prevent another unexpected method getting exported
// the test should be renamed to something like "exposes user-defined methods only"
expect(sharedMethodName).to.deep.equal(['bar']);

// lenient version, reveals the intent of preventing super_ from being exposed
expect(sharedMethodNames).to.contain('bar').and.not.contain('super_')
```

Note I didn't test the code (the syntax might be incorrect), but I hope it illustrates my point.