Don't delete object key when it equals the rename.to in a rename with regex

[paixaop]

Separating out the rename fix from thekeysToLowerCase

Description copied from original pull request #1763, for easier reference.

Calling rename with a regex where the key matches the rename.to causes the key to get deleted from the object.

Example: I use the folllowing schema to validate an AWS x-api-key header:

Joi.object()
    .keys({
        'x-api-key': stringsSchema.awsApiKey.required(),
    })
    .rename(/x-api-key/i, 'x-api-key', {
        // alias: true,
        override: true,
        ignoreUndefined: true,
    })

Using rename to force a value such as 'X-ApI-KeY' to be all lower case, and therefore normalizing it to 'x-api-key'.
The bug is when the header is already all lower case 'x-api-key', the rename.from is the same as rename.to so it gets deleted if option.alias = false, leaving the object with no x-api-key at all.

So this:

const Joi = require('joi');

const schema = Joi.object()
    .keys({
        'x-api-key': Joi.string().token().min(30).max(128),
    })
    .rename(/x-api-key/i, 'x-api-key', {
        // alias: true,
        override: true,
        ignoreUndefined: true,
    });

const result = Joi.attempt({
      'x-api-key': 'ABCEFGHIJKLMNOPQRSTUVXYWZabcefghijklmnopqrstuvxywz0123456789'
 }, schema);

console.log(result); // prints { }

[lock]

This thread has been automatically locked due to inactivity. Please open a new issue for related bugs or questions following the new issue template instructions.