import path from 'path';

function getModulePackageName(module) {
  if (!module.context) return null;
  const nodeModulesPath = path.join(__dirname, '../node_modules/');

  if (module.context.substring(0, nodeModulesPath.length) !== nodeModulesPath) {
    return null;
  }

  const moduleRelativePath = module.context.substring(nodeModulesPath.length);
  const [moduleDirName] = moduleRelativePath.split(path.sep);
  let packageName = moduleDirName; // handle tree shaking

  if (packageName && packageName.match('^_')) {
    // eslint-disable-next-line prefer-destructuring
    packageName = packageName.match(/^_(@?[^@]+)/)[1];
  }

  return packageName;
}

export const chainWebpack = config => {
  // optimize chunks
  config.optimization // share the same chunks across different modules
    .runtimeChunk(false)
    .splitChunks({
      chunks: 'all',
      // name: 'vendors',
      maxInitialRequests: Infinity,
      minSize: 0,
      cacheGroups: {
        commonDependencies: {
          test (module) {
            const reg = /[\\/]node_modules[\\/]/g
            return reg.test(module.context)
          },
          priority: 1,
          name: 'commonDependencies.js'
        },
      },
    });
};