TypeError: util.promisify is not a function

[Jamesking56]

• Operating System: Ubuntu 18.04 LTS
• Node Version: v6.14.1
• NPM Version: v6.13.6
• webpack Version: 4.41.5 (usage via Symfony Encore)
• compression-webpack-plugin Version: 3.1.0

Expected Behavior

Running encore production builds successfully.

Actual Behavior

encore production fails with:

TypeError: util.promisify is not a function

Code

Usage is with Symfony encore, so essentially its this:

let CompressionPlugin = require('compression-webpack-plugin')

Encore
	.addPlugin(new CompressionPlugin())


... lots more stuff ...

Which matches your Readme.

How Do We Reproduce?

Try following your Readme in Node v6.14.1, I believe this is a BC-break that has happened. This only started happening after I upgraded from 2.0.0.

Your Readme states This module requires a minimum of Node v6.9.0 and Webpack v4.0.0. which I am still meeting.

[alexander-akait]

We don't support node@6 https://github.com/webpack-contrib/compression-webpack-plugin/blob/master/package.json#L16, please update node version

[alexander-akait]

We need fix the README file