webpack: configuration.entry should be an non-empty object

Question

serverless deploy is throwing this error with latest webpack verstion.

Serverless: Bundling with Webpack...

  Webpack Options Validation Error -----------------------

  WebpackOptionsValidationError: Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
 - configuration.entry should be a non-empty object.

webpack.config.js


    const path = require('path');
    const slsw = require('serverless-webpack');
    // var nodeExternals = require('webpack-node-externals')

    module.exports = {
      mode: slsw.lib.webpack.isLocal ? 'development' : 'production',
      entry: slsw.lib.entries,
      // externals: [nodeExternals()],
      devtool: 'source-map',
      resolve: {
        extensions: ['.js', '.jsx', '.json', '.ts', '.tsx'],
      },
      output: {
        libraryTarget: 'commonjs',
        path: path.join(__dirname, '.webpack'),
        filename: '[name].js',
      },
      target: 'node',
      module: {
        rules: [
          // all files with a `.ts` or `.tsx` extension will be handled by `ts-loader`
          { test: /\.tsx?$/, loader: 'ts-loader' },
        ],
      },
    };

package.json


    "serverless": "^1.72.0",
    "serverless-aws-documentation": "^1.1.0",
    "serverless-dynamodb-local": "^0.2.39",
    "serverless-iam-roles-per-function": "^2.0.2",
    "serverless-offline": "^6.4.0",
    "serverless-reqvalidator-plugin": "^1.0.3",
    "serverless-s3-local": "^0.6.2",
    "serverless-webpack": "^5.3.2",
    "ts-loader": "^7.0.5",
    "typescript": "^3.9.5",
    "webpack": "^4.43.0"

there's something related here: https://github.com/serverless-heaven/serverless-webpack/issues/372

serverless.yml is very standard and was working with older webpack versions. Not expert in webpack here, any help much appreciated.

For me this happened if there were not any functions or resources added to the stack file. — ROKIKOKI, Jan 19 '21 at 11:32

score 0 · Answer 1 · answered Jun 18 '20 at 02:55

The solution for this was to recreate the project with from the scratch and reinstall the packages:
sls create --template aws-nodejs-typescript --path projectname

in this case, the webpack.config.json generate looks like this:

const path = require('path');
const slsw = require('serverless-webpack');
const nodeExternals = require('webpack-node-externals');
const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin');

module.exports = {
  context: __dirname,
  mode: slsw.lib.webpack.isLocal ? 'development' : 'production',
  entry: slsw.lib.entries,
  devtool: slsw.lib.webpack.isLocal ? 'cheap-module-eval-source-map' : 'source-map',
  resolve: {
    extensions: ['.mjs', '.json', '.ts'],
    symlinks: false,
    cacheWithContext: false,
  },
  output: {
    libraryTarget: 'commonjs',
    path: path.join(__dirname, '.webpack'),
    filename: '[name].js',
  },
  target: 'node',
  externals: [nodeExternals()],
  module: {
    rules: [
      // all files with a `.ts` or `.tsx` extension will be handled by `ts-loader`
      {
        test: /\.(tsx?)$/,
        loader: 'ts-loader',
        exclude: [
          [
            path.resolve(__dirname, 'node_modules'),
            path.resolve(__dirname, '.serverless'),
            path.resolve(__dirname, '.webpack'),
          ],
        ],
        options: {
          transpileOnly: true,
          experimentalWatchApi: true,
        },
      },
    ],
  },
  plugins: [
    // new ForkTsCheckerWebpackPlugin({
    //   eslint: true,
    //   eslintOptions: {
    //     cache: true
    //   }
    // })
  ],
};

and package.json:

    "@types/aws-lambda": "^8.10.17",
    "@types/node": "^10.12.18",
    "fork-ts-checker-webpack-plugin": "^3.0.1",
    "serverless": "^1.73.1",
    "serverless-aws-documentation": "^1.1.0",
    "serverless-dynamodb-local": "^0.2.39",
    "serverless-iam-roles-per-function": "^2.0.2",
    "serverless-offline": "^6.4.0",
    "serverless-reqvalidator-plugin": "^1.0.3",
    "serverless-s3-local": "^0.6.2",
    "serverless-webpack": "^5.2.0",
    "ts-loader": "^5.3.3",
    "typescript": "^3.2.4",
    "webpack": "^4.29.0",
    "webpack-node-externals": "^1.7.2"

deployment both offline and cloud works ok.

webpack: configuration.entry should be an non-empty object

1 Answers1