Pass the request to the queryString function

[ttshivers]

Prerequisites

• [X] I have written a descriptive issue title
• [X] I have searched existing issues to ensure the feature has not already been requested

🚀 Feature Proposal

It would be great to have access to the request object when passing a function for the queryString function in the same way that rewriteRequestHeaders has access to the request object.

Motivation

I'd like to be able to set the queryString based on other data present in the request including potentially injected data from a preHandler.

Example

proxy.register(require('@fastify/reply-from'), {
  base: 'http://localhost:3001/',
  queryString(search, reqUrl, req) {
    return {
      authToken: req.authToken,
    };
  },
})

[mcollina]

Thanks for reporting! Would you like to send a Pull Request to address this issue? Remember to add unit tests.

[ttshivers]

Yes I can make a PR for this.