Appends the allowed object keys in typescript

[mr-kenikh]

If you try to appends a strongly typed object schema

import Joi from 'joi'

type TSchema = {
  a: Joi.StringSchema
  b: Joi.NumberSchema
}

const schema = Joi.object<TSchema>({
  a: Joi.string(),
  b: Joi.number(),
})

const schemaExtended = schema.append({
  c: Joi.boolean(),
})

it result in error

Argument of type '{ a: Joi.StringSchema; b: Joi.NumberSchema; c: Joi.BooleanSchema; }' is not assignable to parameter of type 'SchemaMap<TSchema>'.
Object literal may only specify known properties, and 'c' does not exist in type 'SchemaMap<TSchema>'.

I suggested a commit that would make possible to do that:

import Joi from 'joi'

type TSchema = {
  a: Joi.StringSchema
  b: Joi.NumberSchema
}

type TSchemaExtended = TSchema & {
  c: Joi.BooleanSchema
}

const schema = Joi.object<TSchema>({
  a: Joi.string(),
  b: Joi.number(),
})

const schemaExtended = schema.append<TSchemaExtended>({
  c: Joi.boolean(),
})

[hueniverse]

Thanks! Can you add this to the TS test file?

[mr-kenikh]

Tests already exists, this commit fix:

• IDE (like Visual Studio Code) error highlighting
• and TypeScript compile error