gulp-polymin2

1.0.2 verified Fri May 01 auth: no javascript deprecated

A Gulp plugin to optimize Polymer 2 components by minifying HTML, JavaScript, and CSS. It uses Babel for JS transpilation (with presets like 'babili' or 'es2015'), cssclean for CSS minification, and integrates uglify-js for JS minification. Current stable version is 1.0.2. Release cadence is low; last update was around 2017. Useful for legacy Polymer 2 builds but no longer actively maintained.

Common errors

error Error: Cannot find module 'cssclean' ↓

cause cssclean is not included as a dependency of gulp-polymin2.

fix

Install cssclean separately: npm install --save-dev cssclean.

error TypeError: polymin is not a function ↓

cause Using default import syntax (ESM) with CommonJS module.

fix

Use require: var polymin = require('gulp-polymin2');

error gulp-polymin2: option 'babelPressets' not recognized ↓

cause Misspelled option name; actual is 'babelPresets'.

fix

Use babelPresets instead of babelPressets.

Warnings

deprecated Package is deprecated; no longer maintained. Use modern tools like polymer-build or webpack. ↓

fix Migrate to polymer-cli or @polymer/build.

gotcha Option name 'babelPressets' is misspelled (should be 'babelPresets'). Using 'babelPressets' will be ignored. ↓

fix Use correct option: { babelPresets: 'es2015' }.

gotcha If jsOptions is null, uglify-js is not applied. Some expect minification by default. ↓

fix Explicitly set jsOptions to {} to enable uglify with defaults.

breaking Requires Babel 6; incompatible with Babel 7+. ↓

fix Use babel-core@^6.0.0 or switch to a modern tool.

Install

npm install gulp-polymin2

yarn add gulp-polymin2

pnpm add gulp-polymin2

Imports

polymin

wrong

import polymin from 'gulp-polymin2';

correct

var polymin = require('gulp-polymin2');

CommonJS require; ESM import not supported.

polymin (default)

wrong

const { polimin } = require('gulp-polymin2');

correct

const polymin = require('gulp-polymin2');

Default export only, not named.

gulp.pipe
wrong
```
.pipe(new polymin(options))
```
correct
```
.pipe(polymin(options))
```
polymin is a function returning a transform stream, not a constructor.

Quickstart

This shows how to set up a Gulp task that uses gulp-polymin2 to optimize Polymer 2 HTML components.

var gulp = require('gulp');
var polymin = require('gulp-polymin2');

gulp.task('compress', function() {
  return gulp.src('src/*.html')
    .pipe(polymin({
      babelPressets: 'es2015',
      cssOptions: {},
      jsOptions: null
    }))
    .pipe(gulp.dest('dist'));
});