Nuxt.js middleware to enable redirects to absolute URLs

redirects.js

import url from 'url'
import qs from 'qs'

export default function (ctx) {
  fixRedirect(ctx)
  const { route, redirect } = ctx
  const { path, query } = route

  // Redirect trailing slashes, preserving query string: /foo/ -> /foo
  if (path.length > 1 && path.slice(-1) === '/') {
    const dest = path.replace(/\/+$/, '') || '/'
    return redirect(301, dest, query)
  }

  // Other redirects
  if (redirects[path]) {
    return redirect(301, redirects[path], query)
  }
}

const redirects = {
  '/foo': '/foo/bar',
  '/baz': '/foo/bar/baz'
}

// The redirect function in Nuxt/Vue doesn’t support absolute URLs.
// https://github.com/nuxt/nuxt.js/issues/770
function fixRedirect (ctx) {
  const _redirect = ctx.redirect
  ctx.redirect = function (status, path, query) {
    // If only 1 or 2 arguments: redirect('/') or redirect('/', { foo: 'bar' })
    if (typeof status === 'string' && (typeof path === 'undefined' || typeof path === 'object')) {
      query = path || {}
      path = status
      status = 302
    }
    path = addQuery(path, query)
    if (!isAbsolute(path)) {
      _redirect(status, path)
    } else if (ctx.isServer && ctx.res) {
      ctx.res.setHeader('Location', path)
      ctx.error({ statusCode: status, message: `Redirecting to ${path}` })
    } else if (ctx.isClient && window && window.location) {
      window.location = path
      ctx.error({ statusCode: status, message: `Redirecting to ${path}` })
    }
  }
}

function isAbsolute (path) {
  return (path.indexOf('//') === 0 || url.parse(path).protocol)
}

function addQuery (path, query) {
  if (!query) {
    return path
  }
  const q = qs.stringify(query)
  if (q === '') {
    return path
  }
  // Append query string with ? or & if a querystring already exists
  path = path + (path.indexOf('?') > 0 ? '&' : '?') + q
  return path
}

ctx.isServer and ctx.isClient should be replaced with process.server and process.client

where should this be put?

I’m pretty sure this doesn’t work with Nuxt 3. Sorry!