`Undefined node "type"` error will occur when I use webpack in production mode

When I pack code in development mode, it will work properly. But if I use production mode, error like bellow will occur everytime.

Input is: ['a' => 1]:

Uncaught Error: Undefined node "string"
    at main.js:210
    at n.read_scalar (main.js:174)
    at n.read_expr_item (main.js:144)
    at n.read_expr (main.js:144)
    at n.read_array_pair_list (main.js:129)
    at n.read_array (main.js:129)
    at n.read_scalar (main.js:174)
    at n.read_expr_item (main.js:144)
    at n.read_expr (main.js:144)
    at n.read_statement (main.js:179)

I’ve tried both 2.x & 3.x-alpha, same result got.

[takashiki]

I used webpack with minimal config like bellow for a test, and got that error:

const path = require('path');

module.exports = {
    entry: './src/index.js',
    output: {
        path: path.join(__dirname, 'dist'),
        filename: '[name].js'
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                use: {
                  loader: 'babel-loader',
                  query: {
                    presets: ['env', 'stage-0']
                  }
                }
            }
        ]
    },
    devServer: {
        contentBase: path.join(__dirname, "dist"),
        port: 9090,
        host: 'localhost',
        overlay: true,
        compress: true
    }
}

And when I used it in my project with a complicated config file, I got that error too.

However, it worked properly when I tested with your webpack config.

[ichiriac]

Hi @takashiki, the problem should be resolved by using version 3.0.0-prerelease.2