An implementation of the WHATWG URL Standard in JavaScript
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Latest commit a7ca3ca Aug 18, 2018


whatwg-url is a full implementation of the WHATWG URL Standard. It can be used standalone, but it also exposes a lot of the internal algorithms that are useful for integrating a URL parser into a project like jsdom.

Specification conformance

whatwg-url is currently up to date with the URL spec up to commit 6ef17eb.

For file: URLs, whose origin is left unspecified, whatwg-url chooses to use a new opaque origin (which serializes to "null").


The URL and URLSearchParams classes

The main API is provided by the URL and URLSearchParams exports, which follows the spec's behavior in all ways (including e.g. USVString conversion). Most consumers of this library will want to use these.

Low-level URL Standard API

The following methods are exported for use by places like jsdom that need to implement things like HTMLHyperlinkElementUtils. They mostly operate on or return an "internal URL" or "URL record" type.

The stateOverride parameter is one of the following strings:

The URL record type has the following API:

These properties should be treated with care, as in general changing them will cause the URL record to be in an inconsistent state until the appropriate invocation of basicURLParse is used to fix it up. You can see examples of this in the URL Standard, where there are many step sequences like "4. Set context object’s url’s fragment to the empty string. 5. Basic URL parse input with context object’s url as url and fragment state as state override." In between those two steps, a URL record is in an unusable state.

The return value of "failure" in the spec is represented by null. That is, functions like parseURL and basicURLParse can return either a URL record or null.

Development instructions

First, install Node.js. Then, fetch the dependencies of whatwg-url, by running from this directory:

npm install

To run tests:

npm test

To generate a coverage report:

npm run coverage

To build and run the live viewer:

npm run build
npm run build-live-viewer

Serve the contents of the live-viewer directory using any web server.