shape() validation crash on undefined

[xuntaka]

Describe the bug

Nope.object().shape({a: Nope.string()}).validate(undefined);
TypeError: Cannot read property 'validate' of undefined

Nope.object().shape({a: Nope.string()}).validate();
TypeError: Cannot read property 'validate' of undefined

Expected behavior
It should return undefined like other items validation eg

Nope.array().of(Nope.string()).validate();
undefined

[xuntaka]

And it's look like shape validation not work generally

 let sss = Nope.object().shape({ a: Nope.string().required() })
undefined
 sss.validate({ b: 123 })
{ a: 'This field is required' }
 sss.validate({ a: 123 })
undefined
 sss.validate({ a: [123] })
undefined

[xuntaka]

Ouhhh

 Nope.array().of(Nope.string()).validate(1);
TypeError: entry.some is not a function