Context

• node version: 12.6.0
• joi version: 15.1.1
• environment: node
• used with: standalone

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

const schema = Joi.number()
const result = schema.validate('-0')

Which result you had ?

error type 'number.unsafe'

What did you expect ?

{ error: null, value: 0 }

because:

const schema = Joi.number()
schema.validate('+0') // => { error: null, value: 0 }