TerserPlugin.test.js

import crypto from 'crypto';

import path from 'path';

import { SourceMapConsumer } from 'source-map';
import CopyWebpackPlugin from 'copy-webpack-plugin';
import RequestShortener from 'webpack/lib/RequestShortener';
import { javascript } from 'webpack';
import MainTemplate from 'webpack/lib/MainTemplate';
import ChunkTemplate from 'webpack/lib/ChunkTemplate';

import TerserPlugin from '../src/index';

import {
  BrokenCodePlugin,
  compile,
  countPlugins,
  getCompiler,
  getErrors,
  getWarnings,
  readsAssets,
  removeCache,
} from './helpers';

jest.setTimeout(10000);

describe('TerserPlugin', () => {
  const rawSourceMap = {
    version: 3,
    file: 'test.js',
    names: ['bar', 'baz', 'n'],
    sources: ['one.js', 'two.js'],
    sourceRoot: 'http://example.com/www/js/',
    mappings:
      'CAAC,IAAI,IAAM,SAAUA,GAClB,OAAOC,IAAID;CCDb,IAAI,IAAM,SAAUE,GAClB,OAAOA',
  };
  const emptyRawSourceMap = {
    version: 3,
    sources: [],
    mappings: '',
  };

  beforeEach(() => Promise.all([removeCache()]));

  afterEach(() => Promise.all([removeCache()]));

  it('should work (without options)', async () => {
    const compiler = getCompiler();

    new TerserPlugin().apply(compiler);

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should work in multi compiler mode', async () => {
    const multiCompiler = getCompiler([
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/entry.js`,
        output: {
          path: `${__dirname}/dist`,
          filename: '[name]-1.js',
          chunkFilename: '[id]-1.[name].js',
        },
        optimization: {
          minimize: false,
        },
      },
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/entry.js`,
        output: {
          path: `${__dirname}/dist`,
          filename: '[name]-2.js',
          chunkFilename: '[id]-2.[name].js',
        },
        optimization: {
          minimize: false,
        },
        plugins: [new TerserPlugin()],
      },
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/import-export/entry.js`,
        output: {
          path: `${__dirname}/dist-MultiCompiler`,
          filename: '[name]-3.js',
          chunkFilename: '[id]-3.[name].js',
        },
        optimization: {
          minimize: false,
        },
        plugins: [new TerserPlugin()],
      },
    ]);

    const emptyPluginCount = countPlugins(multiCompiler.compilers[0]);
    const expectedPluginCount = countPlugins(multiCompiler.compilers[1]);

    expect(emptyPluginCount).not.toEqual(expectedPluginCount);

    multiCompiler.compilers.slice(2).forEach((compiler) => {
      const pluginCount = countPlugins(compiler);

      expect(pluginCount).not.toEqual(emptyPluginCount);
      expect(pluginCount).toEqual(expectedPluginCount);
      expect(pluginCount).toMatchSnapshot('compiler plugin count');
    });

    const multiStats = await compile(multiCompiler);

    multiStats.stats.forEach((stats, index) => {
      expect(
        readsAssets(multiCompiler.compilers[index], stats)
      ).toMatchSnapshot('assets');
      expect(getErrors(stats)).toMatchSnapshot('errors');
      expect(getWarnings(stats)).toMatchSnapshot('warnings');
    });
  });

  it('should work when some of assets do not contain source maps', async () => {
    const compiler = getCompiler({
      devtool: 'source-map',
      module: {
        rules: [
          {
            test: /\.js$/i,
            loader: require.resolve('./fixtures/emit-loader.js'),
          },
        ],
      },
    });

    new TerserPlugin().apply(compiler);

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should work in multi compiler mode with the one plugin', async () => {
    const plugins = [new TerserPlugin()];
    const multiCompiler = getCompiler([
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/entry.js`,
        output: {
          path: `${__dirname}/dist`,
          filename: '[name]-1.js',
          chunkFilename: '[id]-1.[name].js',
        },
        optimization: {
          minimize: false,
        },
      },
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/entry.js`,
        output: {
          path: `${__dirname}/dist`,
          filename: '[name]-2.js',
          chunkFilename: '[id]-2.[name].js',
        },
        optimization: {
          minimize: false,
        },
        plugins,
      },
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/import-export/entry.js`,
        output: {
          path: `${__dirname}/dist-MultiCompiler`,
          filename: '[name]-3.js',
          chunkFilename: '[id]-3.[name].js',
        },
        optimization: {
          minimize: false,
        },
        plugins,
      },
    ]);

    const emptyPluginCount = countPlugins(multiCompiler.compilers[0]);
    const expectedPluginCount = countPlugins(multiCompiler.compilers[1]);

    expect(emptyPluginCount).not.toEqual(expectedPluginCount);

    multiCompiler.compilers.slice(2).forEach((compiler) => {
      const pluginCount = countPlugins(compiler);

      expect(pluginCount).not.toEqual(emptyPluginCount);
      expect(pluginCount).toEqual(expectedPluginCount);
      expect(pluginCount).toMatchSnapshot('compiler plugin count');
    });

    const multiStats = await compile(multiCompiler);

    multiStats.stats.forEach((stats, index) => {
      expect(
        readsAssets(multiCompiler.compilers[index], stats)
      ).toMatchSnapshot('assets');
      expect(getErrors(stats)).toMatchSnapshot('errors');
      expect(getWarnings(stats)).toMatchSnapshot('warnings');
    });
  });

  it('should work in multi compiler mode with the one plugin and with the same file', async () => {
    const plugins = [new TerserPlugin()];
    const multiCompiler = getCompiler([
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/entry.js`,
        output: {
          path: `${__dirname}/dist-0`,
          filename: '[name].js',
          chunkFilename: '[id].[name].js',
        },
        optimization: {
          minimize: false,
        },
        plugins,
      },
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/entry.js`,
        output: {
          path: `${__dirname}/dist-1`,
          filename: '[name].js',
          chunkFilename: '[id].[name].js',
        },
        optimization: {
          minimize: false,
        },
        plugins,
      },
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/entry.js`,
        output: {
          path: `${__dirname}/dist-2`,
          filename: '[name].js',
          chunkFilename: '[id].[name].js',
        },
        optimization: {
          minimize: false,
        },
        plugins,
      },
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/entry.js`,
        output: {
          path: `${__dirname}/dist-3`,
          filename: '[name].js',
          chunkFilename: '[id].[name].js',
        },
        optimization: {
          minimize: false,
        },
        plugins,
      },
      {
        mode: 'production',
        bail: true,
        cache: getCompiler.isWebpack4() ? false : { type: 'memory' },
        entry: `${__dirname}/fixtures/entry.js`,
        output: {
          path: `${__dirname}/dist-4`,
          filename: '[name].js',
          chunkFilename: '[id].[name].js',
        },
        optimization: {
          minimize: false,
        },
        plugins,
      },
    ]);

    const multiStats = await compile(multiCompiler);

    multiStats.stats.forEach((stats, index) => {
      expect(
        readsAssets(multiCompiler.compilers[index], stats)
      ).toMatchSnapshot('assets');
      expect(getErrors(stats)).toMatchSnapshot('errors');
      expect(getWarnings(stats)).toMatchSnapshot('warnings');
    });
  });

  it('should work as a plugin', async () => {
    const compiler = getCompiler({
      plugins: [new TerserPlugin()],
    });

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should work as a minimizer', async () => {
    const compiler = getCompiler({
      optimization: {
        minimize: true,
        minimizer: [new TerserPlugin()],
      },
    });

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should work with "file-loader"', async () => {
    const compiler = getCompiler({
      entry: path.resolve(__dirname, 'fixtures/file-loader.js'),
    });

    new TerserPlugin().apply(compiler);

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should work with "asset" module type', async () => {
    if (getCompiler.isWebpack4()) {
      expect(true).toBe(true);
    } else {
      const compiler = getCompiler({
        entry: path.resolve(__dirname, 'fixtures/asset-resource.js'),
        experiments: {
          asset: true,
        },
        module: {
          rules: [
            {
              test: /emitted\.js$/i,
              type: 'asset/resource',
              generator: {
                filename: '[name][ext]',
              },
            },
          ],
        },
      });

      new TerserPlugin().apply(compiler);

      const stats = await compile(compiler);

      expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
      expect(getErrors(stats)).toMatchSnapshot('errors');
      expect(getWarnings(stats)).toMatchSnapshot('warnings');
    }
  });

  it('should work and respect "terser" errors (the "parallel" option is "true")', async () => {
    const compiler = getCompiler();

    new TerserPlugin({
      parallel: true,
      minify(input) {
        // eslint-disable-next-line global-require
        return require('terser').minify(`${input}1()2()3()`);
      },
    }).apply(compiler);

    const stats = await compile(compiler);

    expect(/node_modules(\/|\\)terser/.test(stats.compilation.errors[0])).toBe(
      true
    );
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should work and respect "terser" errors (the "parallel" option is "false")', async () => {
    const compiler = getCompiler();

    new TerserPlugin({
      parallel: false,
      minify(input) {
        // eslint-disable-next-line global-require
        return require('terser').minify(`${input}1()2()3()`);
      },
    }).apply(compiler);

    const stats = await compile(compiler);

    expect(/node_modules(\/|\\)terser/.test(stats.compilation.errors[0])).toBe(
      true
    );
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should regenerate hash', async () => {
    if (getCompiler.isWebpack4()) {
      const originalMainTemplateUpdateHashForChunk =
        MainTemplate.prototype.updateHashForChunk;
      const originalChunkTemplateUpdateHashForChunk =
        ChunkTemplate.prototype.updateHashForChunk;
      const mockMainTemplateUpdateHashForChunk = jest.fn();
      const mockChunkTemplateUpdateHashFocChunk = jest.fn();

      MainTemplate.prototype.updateHashForChunk = mockMainTemplateUpdateHashForChunk;
      ChunkTemplate.prototype.updateHashForChunk = mockChunkTemplateUpdateHashFocChunk;

      const compiler = getCompiler({
        entry: {
          js: `${__dirname}/fixtures/entry.js`,
          mjs: `${__dirname}/fixtures/entry.mjs`,
          importExport: `${__dirname}/fixtures/import-export/entry.js`,
          AsyncImportExport: `${__dirname}/fixtures/async-import-export/entry.js`,
        },
        output: {
          path: `${__dirname}/dist`,
          filename: '[name].[contenthash].js',
          chunkFilename: '[id].[name].[contenthash].js',
        },
      });

      new TerserPlugin().apply(compiler);

      const stats = await compile(compiler);

      expect(getErrors(stats)).toMatchSnapshot('errors');
      expect(getWarnings(stats)).toMatchSnapshot('warnings');

      // On each chunk we have 2 calls (we have 1 async chunk and 4 initial).
      // First call do `webpack`.
      // Second call do `TerserPlugin`.

      // We have 1 async chunk (1 * 2 = 2 calls for ChunkTemplate)
      expect(mockMainTemplateUpdateHashForChunk).toHaveBeenCalledTimes(8);
      // We have 4 initial chunks (4 * 2 = 8 calls for MainTemplate)
      expect(mockChunkTemplateUpdateHashFocChunk).toHaveBeenCalledTimes(2);

      expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');

      MainTemplate.prototype.updateHashForChunk = originalMainTemplateUpdateHashForChunk;
      ChunkTemplate.prototype.updateHashForChunk = originalChunkTemplateUpdateHashForChunk;
    } else {
      const mockUpdateHashForChunk = jest.fn();
      const compiler = getCompiler({
        entry: {
          js: `${__dirname}/fixtures/entry.js`,
          mjs: `${__dirname}/fixtures/entry.mjs`,
          importExport: `${__dirname}/fixtures/import-export/entry.js`,
          AsyncImportExport: `${__dirname}/fixtures/async-import-export/entry.js`,
        },
        output: {
          path: `${__dirname}/dist`,
          filename: '[name].[contenthash].js',
          chunkFilename: '[id].[name].[contenthash].js',
        },
      });

      compiler.hooks.thisCompilation.tap('TerserPlugin', (compilation) => {
        javascript.JavascriptModulesPlugin.getCompilationHooks(
          compilation
        ).chunkHash.tap('TerserPlugin', mockUpdateHashForChunk);
      });

      new TerserPlugin().apply(compiler);

      const stats = await compile(compiler);

      expect(getErrors(stats)).toMatchSnapshot('errors');
      expect(getWarnings(stats)).toMatchSnapshot('warnings');

      // On each chunk we have 2 calls (we have 1 async chunk and 4 initial).
      // First call do `webpack`.
      // Second call do `TerserPlugin`.

      // We have 1 async chunk (1 * 2 = 2 calls) and 4 initial chunks (4 * 2 = 8 calls)
      expect(mockUpdateHashForChunk).toHaveBeenCalledTimes(10);

      expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    }
  });

  it('isSourceMap method', () => {
    expect(TerserPlugin.isSourceMap(null)).toBe(false);
    expect(TerserPlugin.isSourceMap()).toBe(false);
    expect(TerserPlugin.isSourceMap({})).toBe(false);
    expect(TerserPlugin.isSourceMap([])).toBe(false);
    expect(TerserPlugin.isSourceMap('foo')).toBe(false);
    expect(TerserPlugin.isSourceMap({ version: 3 })).toBe(false);
    expect(TerserPlugin.isSourceMap({ sources: '' })).toBe(false);
    expect(TerserPlugin.isSourceMap({ mappings: [] })).toBe(false);
    expect(TerserPlugin.isSourceMap({ version: 3, sources: '' })).toBe(false);
    expect(TerserPlugin.isSourceMap({ version: 3, mappings: [] })).toBe(false);
    expect(TerserPlugin.isSourceMap({ sources: '', mappings: [] })).toBe(false);
    expect(
      TerserPlugin.isSourceMap({ version: 3, sources: '', mappings: [] })
    ).toBe(false);
    expect(TerserPlugin.isSourceMap(rawSourceMap)).toBe(true);
    expect(TerserPlugin.isSourceMap(emptyRawSourceMap)).toBe(true);
  });

  it('buildError method', () => {
    const error = new Error('Message');

    error.stack = null;

    expect(TerserPlugin.buildError(error, 'test.js')).toMatchSnapshot();

    const errorWithLineAndCol = new Error('Message');

    errorWithLineAndCol.stack = null;
    errorWithLineAndCol.line = 1;
    errorWithLineAndCol.col = 1;

    expect(
      TerserPlugin.buildError(
        errorWithLineAndCol,
        'test.js',
        new SourceMapConsumer(rawSourceMap)
      )
    ).toMatchSnapshot();

    const otherErrorWithLineAndCol = new Error('Message');

    otherErrorWithLineAndCol.stack = null;
    otherErrorWithLineAndCol.line = 1;
    otherErrorWithLineAndCol.col = 1;

    expect(
      TerserPlugin.buildError(
        otherErrorWithLineAndCol,
        'test.js',
        new SourceMapConsumer(rawSourceMap),
        new RequestShortener('/example.com/www/js/')
      )
    ).toMatchSnapshot();

    const errorWithStack = new Error('Message');

    errorWithStack.stack = 'Stack';

    expect(
      TerserPlugin.buildError(errorWithStack, 'test.js')
    ).toMatchSnapshot();
  });

  it('should respect the hash options #1', async () => {
    const compiler = getCompiler({
      output: {
        pathinfo: false,
        path: path.resolve(__dirname, 'dist'),
        filename: '[name].js',
        chunkFilename: '[id].[name].js',
        hashDigest: 'hex',
        hashDigestLength: 20,
        hashFunction: 'sha256',
        hashSalt: 'salt',
      },
    });

    new TerserPlugin().apply(compiler);

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should respect hash options #2', async () => {
    function sha256() {
      return crypto.createHash('sha256');
    }

    const compiler = getCompiler({
      output: {
        pathinfo: false,
        path: path.resolve(__dirname, 'dist'),
        filename: '[name].js',
        chunkFilename: '[id].[name].js',
        hashDigest: 'hex',
        hashDigestLength: 20,
        hashFunction: sha256,
        hashSalt: 'salt',
      },
    });

    new TerserPlugin().apply(compiler);

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should emit an error on a broken code in parallel mode', async () => {
    const compiler = getCompiler({
      entry: {
        one: `${__dirname}/fixtures/entry.js`,
        two: `${__dirname}/fixtures/entry.js`,
      },
      optimization: {
        minimize: false,
        noEmitOnErrors: false,
      },
    });

    new BrokenCodePlugin().apply(compiler);

    new TerserPlugin({ parallel: true }).apply(compiler);

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should emit an error on a broken code in not parallel mode', async () => {
    const compiler = getCompiler({
      entry: {
        one: `${__dirname}/fixtures/entry.js`,
        two: `${__dirname}/fixtures/entry.js`,
      },
      optimization: {
        minimize: false,
        noEmitOnErrors: false,
      },
    });

    new BrokenCodePlugin().apply(compiler);

    new TerserPlugin({ parallel: false }).apply(compiler);

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should write stdout and stderr of workers to stdout and stderr of main process in parallel mode', async () => {
    const { write: stdoutWrite } = process.stdout;
    const { write: stderrWrite } = process.stderr;

    let stdoutOutput = '';
    let stderrOutput = '';

    process.stdout.write = (str) => {
      stdoutOutput += str;
    };

    process.stderr.write = (str) => {
      stderrOutput += str;
    };

    const compiler = getCompiler({
      entry: {
        one: `${__dirname}/fixtures/empty.js`,
        two: `${__dirname}/fixtures/empty.js`,
      },
    });

    new TerserPlugin({
      parallel: true,
      minify: () => {
        // eslint-disable-next-line no-console
        process.stdout.write('stdout\n');
        // eslint-disable-next-line no-console
        process.stderr.write('stderr\n');

        return { code: '' };
      },
    }).apply(compiler);

    const stats = await compile(compiler);

    expect(stdoutOutput).toMatchSnapshot('process stdout output');
    expect(stderrOutput).toMatchSnapshot('process stderr output');
    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');

    process.stdout.write = stdoutWrite;
    process.stderr.write = stderrWrite;
  });

  it('should write stdout and stderr of workers to stdout and stderr of main process in not parallel mode', async () => {
    const { write: stdoutWrite } = process.stdout;
    const { write: stderrWrite } = process.stderr;

    let stdoutOutput = '';
    let stderrOutput = '';

    process.stdout.write = (str) => {
      stdoutOutput += str;
    };

    process.stderr.write = (str) => {
      stderrOutput += str;
    };

    const compiler = getCompiler({
      entry: {
        one: `${__dirname}/fixtures/empty.js`,
        two: `${__dirname}/fixtures/empty.js`,
      },
    });

    new TerserPlugin({
      parallel: false,
      minify: () => {
        // eslint-disable-next-line no-console
        process.stdout.write('stdout\n');
        // eslint-disable-next-line no-console
        process.stderr.write('stderr\n');

        return { code: '' };
      },
    }).apply(compiler);

    const stats = await compile(compiler);

    expect(stdoutOutput).toMatchSnapshot('process stdout output');
    expect(stderrOutput).toMatchSnapshot('process stderr output');
    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');

    process.stdout.write = stdoutWrite;
    process.stderr.write = stderrWrite;
  });

  it('should work with "copy-webpack-plugin"', async () => {
    const compiler = getCompiler();

    new CopyWebpackPlugin({
      patterns: [
        {
          from: path.resolve(__dirname, './fixtures/copy.js'),
        },
      ],
    }).apply(compiler);
    new TerserPlugin().apply(compiler);

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should work with child compilation', async () => {
    const compiler = getCompiler({
      entry: path.resolve(__dirname, 'fixtures/worker-loader.js'),
      devtool: false,
      module: {
        rules: [
          {
            test: /\.worker\.js$/i,
            loader: 'worker-loader',
            options: {
              filename: '[name].worker.js',
              chunkFilename: '[name].chunk.worker.js',
            },
          },
        ],
      },
    });

    new TerserPlugin().apply(compiler);

    const stats = await compile(compiler);

    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should work and show minimized assets in stats', async () => {
    const compiler = getCompiler();

    new TerserPlugin().apply(compiler);

    const stats = await compile(compiler);

    expect(stats.toString().indexOf('[minimized]') !== -1).toBe(
      !getCompiler.isWebpack4()
    );
    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });

  it('should work and show related assets in stats', async () => {
    const compiler = getCompiler({
      entry: { comments: `${__dirname}/fixtures/comments-4.js` },
      devtool: 'source-map',
    });

    new TerserPlugin().apply(compiler);

    const stats = await compile(compiler);

    expect(stats.toString().indexOf('2 related asset') !== -1).toBe(
      !getCompiler.isWebpack4()
    );
    expect(readsAssets(compiler, stats)).toMatchSnapshot('assets');
    expect(getErrors(stats)).toMatchSnapshot('errors');
    expect(getWarnings(stats)).toMatchSnapshot('warnings');
  });
});