🚫  Gulp is no longer maintained. The same functionality of this gulp plugin is available as a regular CLI build task without gulp. See: w3c-html-validator

gulp-w3c-html-validator

Gulp plugin to validate HTML using the W3C Markup Validation Service

This Gulp plugin is a wrapper for w3c-html-validator ("A package for testing HTML files or URLs against the W3C validator").  Note that it's usually simpler and cleaner to use the underlying library directly from your package.json file than using this plugin.

A) Setup

Install module into your project:

$ npm install --save-dev gulp-w3c-html-validator

B) Define Task

Create a task in your gulpfile.js:

// Imports
import gulp from 'gulp';
import { htmlValidator } from 'gulp-w3c-html-validator';

// Tasks
const task = {
   validateHtml() {
      return gulp.src('target/**/*.html')
         .pipe(htmlValidator.analyzer())
         .pipe(htmlValidator.reporter());
      },
   };

// Gulp
gulp.task('validate-html', task.validateHtml);

C) Options

1. analyzer()

Name (key)	Type	Default	Description
checkUrl	string	'https://validator.w3.org/nu/'	W3C validation API endpoint.
ignoreLevel	'info' or 'warning'	null	Skip unwanted messages.*
ignoreMessages	string or regex	null	Skip messages containing a string or matching a regular expression.*

*The ignoreMessages and ignoreLevel options only work for 'json' output.  Option value 'warning' also skips 'info'.

Example usage of ignoreMessages option:

// Tasks
const task = {
   validateHtml() {
      return gulp.src('target/**/*.html')
         .pipe(htmlValidator.analyzer({ ignoreMessages: /^Duplicate ID/ }))
         .pipe(htmlValidator.reporter());
      },
   };

2. reporter()

Name (key)	Type	Default	Description
maxMessageLen	number	null	Trim validation messages to not exceed a maximum length.
throwErrors	boolean	false	Throw an error for HTTP validation failure.

D) Custom Reporting

The analyzer() adds the validation results onto each file object in the w3cHtmlValidator field, which contains a validates (boolean) field and a messages (array) field.

Example usage

// Import
import { htmlValidator } from 'gulp-w3c-html-validator';
import through2 from 'through2';

// Tasks
const task = {
   validateHtml() {
      const handleFile = (file, encoding, callback) => {
         callback(null, file);
         if (!file.w3cHtmlValidator.validates)
            throw Error('HTML failed validation');
         };
      return gulp.src('target/**/*.html')
         .pipe(htmlValidator.analyzer())
         .pipe(through2.obj(handleFile));  //custom reporter
      },
   };

// Gulp
gulp.task('validate-html', task.validateHtml);

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MIT License