Uncaught TypeError: URL is not a constructor using WHATWG URL object support for electron

Question

I am trying to read a file using WHATWG URL object support here

and I am getting this error: Uncaught TypeError: URL is not a constructor

here is my code:

var fs = require("fs");                                     
const { URL } = require('url');
var dbPath = 'file://192.168.5.2/db/db.sqlite';
const fileUrl = new URL(dbPath);

Solution 1

I faced the same issue, then I looked into the url module and found a solution

For Node V6 use,

const URL = require('url').Url;

or

const { Url } = require('url'); 

If you look into the module, it exports 5 methods one of which is Url, so if you need to access Url, you can use either of the two methods

Solution 2

Are you using Node 6 instead of Node 8?

Node 6

const url = require('url');
const myUrl = url.parse('http://example.com');
const myUrlString = url.format(myUrl);

https://nodejs.org/dist/latest-v6.x/docs/api/url.html#url_url

Node 8

const { URL } = require('url');
const myUrl = new URL('http://example.com');
const myUrlString = myUrl.toString();

https://nodejs.org/dist/latest-v8.x/docs/api/url.html#url_url

Solution 3

Node v10.0.0 and newer (currently Node v16.x)

URL Class

v10.0.0 | The class is now available on the global object.

As mentioned here: Node.js Documentation - Class: URL

So this should work without require('url'):

const myUrl = new URL('http://example.com');

Solution 4

The docs you took this info out are for the node of version 8.4.0.

If it does not work for you, that means that your node is of version 6.11.2. Then, just change the letter case of URL -

const { Url } = require('url');
const myUrl = new Url('http://example.com'); 

because url module exports Url, not URL.

View more solutions

Comments

[andrhamm]

I had to use const URL = require('url').URL

[Ricky Nelson]

Sigh, it looks like the documentation is wrong here, it does not show the .URL nodejs.org/api/url.html in the various examples.

[SliverNinja - MSFT]

if you are managing multiple node environments - semver can be helpful to determine which method to use based upon the node version

[Biswajit Mohanty]

I think const URL = require('url').Url; will give you null values const URL = require('url').Url; var loginURL = new URL("exampe.com/xyz.html"); console.log(loginURL); node version 8.4.0

[Kowsalya]

@BiswajitMohanty, the above answer was posted for node version 6, for version 8, the method (const { URL } = require('url'); ) mentioned in the question should work fine.

[Kowsalya]

@socketwiz, the documentation is not wrong, requiring a module with {} (const { URL } = require('url');) or using dot notation (const URL = require('url').URL) both must yield same response.