Wildcard domain and pathname regex for redirection

Question

I'm trying to get batch redirection working in cloudflare workers. Here's an array of objects with to and from urls, some will be cross domain.

const redirects = [
  {
    "from": "https://some.domain.tld/product/*",
    "to": "https://another.domain.tld/product/*"
  },
]

I'd like to respect the wildcards and try to redirect based on the pathname of the url.

here's my attempt, but this is just for fixed pathnames and not cross-domain. It's kind of hard to test for cross-domain in the workers playground editor.

async function handleRequest(request) {
  const  url = new URL(request.url)
  const host = url.hostname;
  const path = url.pathname;
  const queryStrings = url.search;

  const location = redirects.find(r => {
      return r.from.includes(path);
  });
  
  if (location) {
   return Response.redirect('https://' + host + location.to + queryStrings, 301)
  }
  return fetch(request)
}

addEventListener("fetch", async event => {
  event.respondWith(handleRequest(event.request))
})

How can I change this code so it respects redirects with wildcards? Wildcards will most likely always be at the end, some pathnames will not have wildcards, and it will not always be /product but any pathname that's in the redirect object.

Updated after answer:

const redirects = [
  {
    "from": "https://red.domain.com/product-1/*",
    "to": "https://blue.domain.com/product-1/*"
  },
]

async function handleRequest(request) {
    const url = 'https://red.domain.com/product-1/fees';
    const location = redirects.reduce((loc, r) => {
      let match = url.split(r.from.replace("*", "")[1]);
      if (match) return r.to.replace("*", "") + match;
  }, "");
  if (location) {
   return Response.redirect(location, 301)
  }
  return fetch(request)
}

addEventListener("fetch", async event => {
  event.respondWith(handleRequest(event.request))
})

result:

https://blue.domain.com/product-1/h,,ps://red.domain.com/produc,-1/fees

Answer 1

You can match the whole URL to your redirects using Array#split(), while getting the part "after" the wildcard back:

console.log(
"https://some.domain.tld/product/foo/bar/baz?test=baf".split("https://some.domain.tld/product/")[1]
)

For URLs that don't match this redirect, the result will be undefined, so:

const redirects = [
  {
    "from": "https://some.domain.tld/product/*",
    "to": "https://another.domain.tld/product/*"
  },
]


async function handleRequest(request) {
  const {url} = request;

  const location = redirects.reduce((loc, r) => {
    let match = url.split(r.from.replace("*","")[1]; // remove wildcard * for matching
    if(match) return r.to.replace("*","") + match;
  },"")
  
  if (location) {
   return Response.redirect(location, 301)
  }
  return fetch(request)
}

addEventListener("fetch", async event => {
  event.respondWith(handleRequest(event.request))
})