image doesn't compressed with loader

Compiler Output

As you see the image size of screenshot.png is around 800KB, no matter what optimization level is used, the image size in build folder is same.

Version Info webpack : 4.12.0

webpack.config.js

const autoprefixer = require('autoprefixer');
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const CopyWebpackPlugin = require('copy-webpack-plugin');
const { ImageminWebpackPlugin, imageminLoader } = require('imagemin-webpack');

// Before imagemin
const imageminGifsicle = require('imagemin-gifsicle');
const imageminJpegtran = require('imagemin-jpegtran');
const imageminOptipng = require('imagemin-optipng');
const imageminPngquant = require('imagemin-pngquant');
const imageminSvgo = require('imagemin-svgo');
const imageminManifest = {};

const path = require('path');
const fs = require('fs');

const appDirectory = fs.realpathSync(process.cwd());

function resolveApp(relativePath) {
  return path.resolve(appDirectory, relativePath);
}

const DEV = process.env.NODE_ENV === 'development';

const paths = {
  appSrc: resolveApp('src'),
  appBuild: resolveApp('build'),
  appIndexJs: resolveApp('src/app.js'),
  appNodeModules: resolveApp('node_modules')
};

module.exports = {
  target: 'web',
  mode: DEV ? 'development' : 'production',
  devtool: DEV ? 'cheap-eval-source-map' : 'source-map',
  entry: {
    app: paths.appIndexJs
  },
  output: {
    filename: DEV ? 'bundle.js' : 'bundle.[hash:8].js',
    path: paths.appBuild
  },
  module: {
    rules: [
      // Disabling require.ensure as it's not a standard language
      { parser: { requireEnsure: false } },

      // js loader
      {
        test: /.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader'
        }
      },
      // css loader
      {
        test: /\.(sass|scss|css)$/,
        use: [{
          loader: MiniCssExtractPlugin.loader
        },{
          loader: 'css-loader',
          options: {
            importLoader: 1
          }
        },{
          loader: 'postcss-loader',
          options: {
            ident: 'postcss',
            plugins: () => [
              autoprefixer({
                browsers: [
                  '>1%',
                  'last 4 versions',
                  'Firefox ESR',
                  'not ie < 9',
                ],
              }),
            ],
          }
        },
        {
          loader: 'sass-loader'
        }]
      },

      //img webpack optimization loader
      {
        test: /\.(png|gif|jpe?g|svg)$/,
        use: [
          {
            loader: 'file-loader',
            options: {
              emitFile: true,
              useRelativePath: true,
              name: "[name].[ext]",
            }
          },
        ]
      }
    ]
  },
  plugins: [
    new MiniCssExtractPlugin({
      filename: "[name].css",
      chunkFilename: "[id].css"
    }),
    new ImageminWebpackPlugin({
      cache: true,
      bail: false, // Ignore errors on corrupted images
      loader: false,
      imageminOptions: {
        plugins: [
          imageminGifsicle({
            interlaced: true,
            optimizationLevel: 3
          }),
          // imageminOptipng({
          //   interlaced: true,
          //   optimizationLevel: 3
          // }),
          imageminPngquant({
            quality: 10,
            speed: 4,
          }),
          imageminJpegtran({
            progressive: true,
            optimizationLevel: 3
          })
        ]
      },
      manifest: imageminManifest, // This object will contain source and interpolated filenames
      // maxConcurrency: os.cpus().length - 1,
      name: "[hash].[ext]",
      test: /\.(jpe?g|png|gif|svg)$/i,
      include: undefined,
      exclude: undefined
    })
  ],
  performance: {
    hints: false
  }
}

[sesn]

@evilebottnawi , Test repo , I have written the test repo to reproduce the error.

[alexander-akait]

Sorry for big delay, fixed in https://github.com/itgalaxy/imagemin-webpack/releases/tag/v4.0.0