Support plan

• is this issue currently blocking your project? (yes/no): yes
• is this issue affecting a production system? (yes/no): no

Context

• node version: v14.6.0
• module version with issue:
• last module version without issue:
• environment (e.g. node, browser, native): node
• used with (e.g. hapi application, another framework, standalone, ...): standalone
• any other relevant information:

What are you trying to achieve or the steps to reproduce?

It looks like stripUnknown doesn't works for nested object when the nested object has invalid fields.

const schema = Joi.object({
    foo: Joi.string(),
    nested: Joi.object({
        bar: Joi.string(),
    })
})

const options = {
    abortEarly: false,
    allowUnknown: true,
    presence: 'required',
    stripUnknown: true,
}

const input = {
    foo: null, // invalid value
    unknown: 'unknown',
    nested: {
        bar: null, // invalid value
        unknown: 'unknown',
    }
}

const { value } = schema.validate(input, options)
// { foo: null, nested: { bar: null, unknown: 'unknown' } }

What was the result you got?

nested.unknow is still present

What result did you expect?

It should have been "stripped"