Web worker for webhint

The webhint web worker utility provides a bundled version of webhint suitable for running inside a web worker in a browser environment.

Installation

This package can be installed via npm by running the following:

npm install @hint/utils-worker --save

A pre-built version of the webhint web worker is included as part of this package named webhint.js. You can locate the file in Node using require.resolve('@hint/utils-worker/webhint.js').

Usage

The included webhint.js file is intended to be loaded via a web worker and communicated with via postMessage. Information about the content to be analyzed must be passed to the worker and the worker will return any issues identified as a result.

const worker = new Worker('webhint.js');

worker.addEventListener('message', (event) => {
    if (event.data.requestConfig) {
        // Tell worker the URL of the page being analyzed.
        worker.postMessage({ config: { resource: 'https://example.com' } });
    } else if (event.data.ready) {
        // Once ready, forward network requests.
        worker.postMessage({ fetchStart });
        worker.postMessage({ fetchEnd });
        // Once ready, forward snapshot of the DOM (see @hint/utils-dom).
        worker.postMessage({ snapshot });
    } else if (event.data.results) {
        // Process/display results (occurs multiple times).
    } else if (event.data.error) {
        // Log/handle fatal errors reported by the worker.
    }
});

The worker contains a subset of hints suitable for running in a browser environment without direct access to the page. These hints can be disabled or configured using the same format as .hintrc files. Just pass the object as userConfig when sending the configuration.

worker.postMessage({
    config: {
        resource: 'https://example.com',
        userConfig: {
            browserslist: 'defaults, not IE 11',
            hints: {
                'compat-api/css': ['error', { ignore: ['border-radius', 'box-lines'] }],
                'css-prefix-order': 'off'
            }
        }
    }
});

All included hints are enabled by default. To disable all included hints and selectively enable only a few, change the default severity.

worker.postMessage({
    config: {
        defaultHintSeverity: 'off',
        userConfig: { hints: { 'button-type': 'default' } }
    }
});

Contributing to the worker

To contribute to the worker please read the CONTRIBUTING.md file of the package.