CODEWITHSUNDEEP
node.jswebpack
Ross Addinall
Ross Addinall

Reputation: 51

How can I debug this Webpack error - ERROR in bundle.js from Terser

I am trying to use webpack to bundle up a Node JS project, for the benefits it offers in terms of minimising the size of the code etc. and bundling together all of the dependencies.

My webpack job is failing with the following error:

ERROR in bundle.js from Terser
Invalid function parameter [bundle.js:186393,23]

This is my webpack.config file:

const path = require('path');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');

module.exports = {
    target: "node",
    mode: "production",
    entry: {
        app: ["./src/vitaq_client.js"]
    },
    // https://webpack.js.org/configuration/node/
    // node: {
    //     global: false,
    //     __filename: true,
    //     __dirname: true,
    // },
    module: {
        // https://github.com/ivan-aksamentov/reactlandia-bolerplate-lite/issues/5#issuecomment-413306341
        exprContextCritical: false,
        rules: [
            {
                test: /\.node$/,
                use: 'node-loader'
            },
            {
                test: /coffee/,
                use: 'node-loader'
            },
            {
                test: /\.coffee$/,
                use: [ 'coffee-loader' ]
            },
            // {
            //     test: /\.map$/,
            //     use: ["source-map-loader"],
            //     enforce: "pre"
            // },
        ]
    },
    plugins: [
        new CleanWebpackPlugin(),
    ],
    output: {
        path: path.resolve(__dirname, "./build"),
        filename: "bundle.js"
    },
};

and this is the command I am using to run it:

webpack --config webpack.config.js

From the searching I have done it seems that there is a Terser plugin for code minification, but as you can see from my config file I am not loading that plugin, so does webpack use that plugin by default? If not how could I be getting an error from Terser ?

If I set the mode to "development" in the config file, then I do not get the problem, but I suspect that is because development code would not get minified.

I am a bit stuck as to how I set about debugging this problem - are there ways of getting more output from Webpack. I have tried using the --json > compilation-stats.json command line argument when I invoke webpack, but I get a huge output file (43Mb) and I can't find anything in all of that to help.

Any suggestions would be gratefully received.

Upvotes: 2

Views: 6443

Answers (1)

ajnauleau
ajnauleau

Reputation: 489

This is an error with assignment where you have an invalid function parameter at the given line of bundle.js.

You can solve this by not minimizing the webpack build:

    optimization: {
        minimize: false
    }

Then finding the assignment error line from the error output, in the non minified bundle.

Invalid function parameter [bundle.js:186393,23]

Hope this helps someone else.

Upvotes: 6

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