const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const NodePolyfillPlugin = require('node-polyfill-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const path = require('path');

module.exports = env => ({
  mode: 'development',
  entry: path.resolve(__dirname, './webpack-tests.js'),
  resolve: {
    alias: {
      'fsProvider': path.resolve(__dirname, '../shims/providers/default'),
    },
  },
  output: {
    path: path.resolve(__dirname, './dist-webpack'),
    filename: 'index.js',
  },
  plugins: [
    new webpack.ContextReplacementPlugin(
      // Mocha safely uses require in such a way that webpack cannot statically extract dependancies.
      // If the ignoreRequestDependancyExpressionWarnings env is set, we will aggregate these warnings
      // into one summary warning to minimise spamming the console.
      /\/node_modules\/mocha\/lib/,
      (data) => {
        if (env.ignoreRequestDependancyExpressionWarnings) {
          let requestDependencyExpressionsIgnored = 0;
          data.dependencies.forEach((dependancy) => {
            if (dependancy.critical === 'the request of a dependency is an expression') {
              dependancy.critical = undefined;
              requestDependencyExpressionsIgnored += 1;
            }
          });
          console.log(`WARNING: Ignoring ${requestDependencyExpressionsIgnored} "request of a dependency is an expression" warnings from "node_modules/mocha/lib".`);
        }
        return data;
      },
    ),
    new NodePolyfillPlugin(),
    new MiniCssExtractPlugin(),
    new HtmlWebpackPlugin({
      title: 'Filer Tests - Webpack Build',
      template: './tests/webpack.index.html',
    }),
  ],
  module: {
    rules: [
      {
        test: /\.css$/i,
        use: [MiniCssExtractPlugin.loader, 'css-loader'],
      },
    ],
  },
  optimization: {
    minimize: false,
  },
  devtool: 'inline-source-map',
  devServer: {
    contentBase: path.resolve(__dirname, './dist-webpack'),
  }
});