html-validate

Offline HTML5 validator. Validates either a full document or a smaller (incomplete) template, e.g. from an AngularJS or Vue.js component.

Features

• Can test fragments of HTML, for instance a component template.
• Does not upload any data to a remote server, all testing is done locally.
• Strict and non-forgiving parsing. It will not try to correct any incorrect markup or guess what it should do.

Bundles

The library comes in four flavours:

• CommonJS full (dist/cjs/main.js)
• CommonJS browser (dist/cjs/browser.js)
• ESM full (dist/es/main.js)
• ESM browser (dist/es/browser.js)

The browser versions contains a slimmed version without CLI dependencies. Your tooling will probably use the correct version but if needed you can import the files directly.

Do note that to run in a browser you still need to polyfill the fs nodejs library.

Browsers and bundlers are currently not 100% supported but is possible with some tricks, see running in browser for more details.

Usage

npm install -g html-validate
html-validate FILENAME..

Configuration

Create .htmlvalidate.json:

{
  "extends": [
    "html-validate:recommended"
  ],

  "rules": {
    "close-order": "error",
    "void": ["warn", {"style": "omit"}]
  }
}

Example

<p>
  <button>Click me!</button>
  <div id="show-me">
    Lorem ipsum
  </div>
</p>

  1:1  error  Element <p> is implicitly closed by adjacent <div>  no-implicit-close
  2:2  error  Button is missing type attribute                    button-type
  6:4  error  Unexpected close-tag, expected opening tag          close-order

Developing

Prerequisites

• NodeJS 12
• NPM 7

Test

Testing is done using jest.

npm test

or call jest directly.

Some tests are autogenerated from documentation examples, use npm run build:docs to build those before running.

Lint

Linting is done using ESLint.

npm run eslint

or call eslint directly.

Build

npm run build

To build documentation use:

npm run build:docs

The documentation can be served locally using:

npm start