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

问题

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

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

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

If not, what way would you suggest for doing this without writing code full of ifs?

回答1:

No. path.join() will return incorrect values when used with URLs.

It sounds like you want url.resolve. From the Node docs:

url.resolve('/one/two/three', 'four')         // '/one/two/four'
url.resolve('http://example.com/', '/one')    // 'http://example.com/one'
url.resolve('http://example.com/one', '/two') // 'http://example.com/two'

Edit: As Andreas correctly points out in a comment, url.resolve would only help if the problem is as simple as the example. url.parse also applies to this question because it returns consistently and predictably formatted fields via the URL object that reduces the need for "code full of ifs".

回答2:

No, you should not use path.join() to join URL elements.

There's a package for doing that now. So rather than reinvent the wheel, write all your own tests, find bugs, fix them, write more tests, find an edge case where it doesn't work, etc., you could use this package.

url-join

https://github.com/jfromaniello/url-join

Install

npm install url-join

Usage

var urljoin = require('url-join');

var fullUrl = urljoin('http://www.google.com', 'a', '/b/cd', '?foo=123');

console.log(fullUrl);

Prints:

'http://www.google.com/a/b/cd?foo=123'

回答3:

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

回答4:

When I tried PATH for concatenating url parts I run into problems. PATH.join stripes '//' down to '/' and this way invalidates an absolute url (eg. http://... -> http:/...). For me a quick fix was:

baseurl.replace(/\/$/,"") + '/' + path.replace(/^\//,"") )

or with the solution posted by Colonel Panic:

[pathA.replace(/^\/|\/$/g,""),pathB.replace(/^\/|\/$/g,"")].join("/")

回答5:

No! On Windows path.join will join with backslashes. HTTP urls are always forward slashes.

How about

> ["posts", "2013"].join("/")
'posts/2013'

回答6:

We do it like this:

var _ = require('lodash');

function urlJoin(a, b) {
  return _.trimEnd(a, '/') + '/' + _.trimStart(b, '/');
}

回答7:

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');

回答8:

If you're using lodash, you can use this simple oneliner:

// returns part1/part2/part3
['part1/', '/part2', '/part3/'].map((s) => _.trim(s, '/')).join('/')

inspired by @Peter Dotchev's answer

回答9:

If you use Angular, you can use Location:

import { Location } from '@angular/common';
// ...
Location.joinWithSlash('beginning', 'end');

Works only on 2 arguments though, so you have to chain calls or write a helper function to do that if needed.

回答10:

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'

回答11:

Typescript custom solution:

export function pathJoin(parts: string[], sep: string) {
  return parts
    .map(part => {
      const part2 = part.endsWith(sep) ? part.substring(0, part.length - 1) : part;
      return part2.startsWith(sep) ? part2.substr(1) : part2;
    })
    .join(sep);
}

expect(pathJoin(['a', 'b', 'c', 'd'], '/')).toEqual('a/b/c/d');
expect(pathJoin(['a/', '/b/', 'c/', 'd'], '/')).toEqual('a/b/c/d');
expect(pathJoin(['http://abc.de', 'users/login'], '/')).toEqual('http://abc.de/users/login');

回答12:

My solution

path.join(SERVER_URL, imageAbsolutePath).replace(':/','://');

Edit: if you want to support windows enviroments

path.join(SERVER_URL, imageAbsolutePath).replace(/\\/g,'/').replace(':/','://');

The second solution will replace all the backslashes, so url parts like querystring and hash may be altered too, but the topic is joining just the url path, so I don't consider it an issue.

回答13:

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

来源：https://stackoverflow.com/questions/16301503/can-i-use-requirepath-join-to-safely-concatenate-urls

标签

node.js

url

string-concatenation