Can I use require(“path”).join to safely concatenate urls?

Question

Is this safe to use require(\"path\").join to concatenate URLs, for example:

require(\"path\").join(\"http://example.com\", \"ok\"); 
//returns          


        

Answer 1

By the time posting this answer url.resolve() is deprecated;

I did following to join to path in Nodejs:

const path = require('path');
const url = require('url');


let myUrl = new URL('http://ignore.com');
myUrl.pathname=path.join(firstpath, secondpath);
console.log(myUrl.pathname)

This approach logs correct url path and it works for my case.

What is your opinion about this approach?

Thanks

Answer 2

This can be accomplished by a combination of Node's path and URL:

1. Require the packages:

const nodeUrl = require('url')
const nodePath = require('path')

2. Start by making a URL object to work with:

> const myUrl = new nodeUrl.URL('https://example.com')

3. Use pathname= and path.join to construct any possible combination:

> myUrl.pathname = nodePath.join('/search', 'for', '/something/')
'/search/for/something/'

(you can see how liberal path.join is with arguments)

4. At this point your URL reflects the ultimate desired result:

> myUrl.toString()
'https://example.com/search/for/something/'

Why this approach?

This technique uses built-in libraries. The less third-party dependencies the better, when it comes to CVEs, maintenance, etc.

PS: Never manipulate URLs as strings!

When I review code I'm adamant about never manipulating URLs as strings manually. For one, look how complicated the spec is.

Secondly, the absence/presence of a trailing/prefixed slash (/) should not cause everything to break! You should never do:

const url = `${baseUrl}/${somePath}`

and especially not:

uri: host + '/' + SAT_SERVICE + '/' + CONSTELLATION + '/',

Of which I have seen.

Answer 3

The WHATWG URL object constructor has a (input, base) version, and the input can be relative using /, ./, ../. Combine this with path.posix.join and you can do anything:

const {posix} = require ("path");
const withSlash = new URL("https://example.com:8443/something/");
new URL(posix.join("a", "b", "c"), withSlash).toString(); // 'https://example.com:8443/something/a/b/c'
new URL(posix.join("./a", "b", "c"), withSlash).toString(); // 'https://example.com:8443/something/a/b/c'
new URL(posix.join("/a", "b", "c"), withSlash).toString(); // 'https://example.com:8443/a/b/c'
new URL(posix.join("../a", "b", "c"), withSlash).toString(); // 'https://example.com:8443/a/b/c'
const noSlash = new URL("https://example.com:8443/something");
new URL(posix.join("./a", "b", "c"), noSlash).toString(); // 'https://example.com:8443/a/b/c'

Answer 4

This is what I use:

function joinUrlElements() {
  var re1 = new RegExp('^\\/|\\/$','g'),
      elts = Array.prototype.slice.call(arguments);
  return elts.map(function(element){return element.replace(re1,""); }).join('/');
}

example:

url = joinUrlElements(config.mgmtServer, '/v1/o/', config.org, '/apps');

Answer 5

There are other working answers, but I went with the following. A little path.join/URL combo.

const path = require('path');
//
const baseUrl = 'http://ejemplo.mx';
// making odd shaped path pieces to see how they're handled.
const pieces = ['way//', '//over/', 'there/'];
//
console.log(new URL(path.join(...pieces), baseUrl).href);
// http://ejemplo.mx/way/over/there/

// path.join expects strings. Just an example how to ensure your pieces are Strings.
const allString = ['down', 'yonder', 20000].map(String);
console.log(new URL(path.join(...allString), baseUrl).href);
// http://ejemplo.mx/down/yonder/20000

Answer 6

Axios has a helper function that can combine URLs.

function combineURLs(baseURL, relativeURL) {
  return relativeURL
    ? baseURL.replace(/\/+$/, '') + '/' + relativeURL.replace(/^\/+/, '')
    : baseURL;
}

Source: https://github.com/axios/axios/blob/fe7d09bb08fa1c0e414956b7fc760c80459b0a43/lib/helpers/combineURLs.js