less-hashed

True incremental build — compile only changed LESS files without watcher.

less-hashed compares the hash of the less files and their dependencies, and returns a tree of only the changed files with their dependencies, to save wasting time regenerating output.

Can be useful:

• For incremental, when you need to compile only changed files and their dependencies. Builds when compiling less with gulp without a watcher, when you deploy for example.
• Simple to calculate and output the dependency tree.

Install

npm install less-hashed --save-dev

Gulp example

Used gulp-filter for filter exclude files.

'use strict';

const gulp = require('gulp');
const less = require('gulp-less');
const filter = require('gulp-filter');
const lessHashed = require('less-hashed');

const config = {
  base: './assets/less/',
  src: './assets/less/**/*.less',
  include: '**/*.less',
  exclude: '!**/_*.less',
  destination: './build/css/',
  settings: {
    relativeUrls: true
  }
};

gulp.task('default', function () {
  const includes = lessHashed(
    config.src,
    {
      hashPath: config.destination,
      force:  process.argv.indexOf('--force') > -1
    }
  );

  return gulp
    .src(includes, { base: config.base })
    .pipe(filter([ config.include, config.exclude ]))
    .pipe(less(config.settings))
    .pipe(gulp.dest(config.destination));
});

Absolute paths

'use strict';

const gulp = require('gulp');
const less = require('gulp-less');
const filter = require('gulp-filter');
const lessHashed = require('less-hashed');

const config = {
  base: './assets/less/',
  src: './assets/less/**/*.less',
  include: '**/*.less',
  exclude: '!**/_*.less',
  destination: './build/css/',
  settings: {
    paths: ['./assets']
  }
};

gulp.task('default', function () {
  const includes = lessHashed(
    config.src,
    {
      hashPath: config.destination,
      force:  process.argv.indexOf('--force') > -1,
      base: config.settings.paths[0]
    }
  );

  return gulp
    .src(includes, { base: config.base })
    .pipe(filter([ config.include, config.exclude ]))
    .pipe(less(config.settings))
    .pipe(gulp.dest(config.destination));
});

API

lessChanged(pathToFiles, [options]);

pathToFiles

Type: String

Path to less files. Use glob patterns. For example './**/*.less'. See node-glob for more info and examples.

options

Type: Object

hashPath

Type: String

Path to save hash file. If undefined — SAVE HASH mode disabled. It's mean files will not be hashed.

hashName

Type: string
Default: hashes.json

Hash file name.

force

Type: boolean
Default: false

Make new hash file and return full tree of less files and their dependencies.