TypeError: Cannot read property 'Reflect' of undefined

[softmarshmallow]

TypeError: Cannot read property 'Reflect' of undefined
    at eval (/file/4hqwYFw6FKw1njvzEl3VUh/PLUGIN_62_SOURCE:47142)
    at eval (/file/4hqwYFw6FKw1njvzEl3VUh/PLUGIN_62_SOURCE:47158)
    at Object../node_modules/reflect-metadata/Reflect.js (/file/4hqwYFw6FKw1njvzEl3VUh/PLUGIN_62_SOURCE:48248)
    at __webpack_require__ (/file/4hqwYFw6FKw1njvzEl3VUh/PLUGIN_62_SOURCE:20)

tsconfig

{
  "compilerOptions": {
    "target": "es2017",
    "outDir": "dist",
    "jsx": "react",
    "lib": [
      "DOM",
      "ES2015.Reflect"
    ],
    "experimentalDecorators": true,
    "removeComments": true,
    "allowSyntheticDefaultImports": true,
    "noImplicitAny": false,
    "moduleResolution": "node",
    "typeRoots": [
      "./node_modules/@types",
      "./node_modules/@figma"
    ]
  }
}

weback

const HtmlWebpackInlineSourcePlugin = require('html-webpack-inline-source-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const path = require('path')

module.exports = (env, argv) => ({
    mode: argv.mode === 'production' ? 'production' : 'development',

    // This is necessary because Figma's 'eval' works differently than normal eval
    devtool: argv.mode === 'production' ? false : 'inline-source-map',

    entry: {
        ui: './src/ui.tsx', // The entry point for your UI code
        code: './src/code.ts', // The entry point for your plugin code
    },

    target: 'node',

    module: {
        rules: [
            // Converts TypeScript code to JavaScript
            { test: /\.tsx?$/, use: 'ts-loader', exclude: /node_modules/ },

            // Enables including CSS by doing "import './file.css'" in your TypeScript code
            { test: /\.css$/, loader: [{ loader: 'style-loader' }, { loader: 'css-loader' }] },

            // Allows you to use "<%= require('./file.svg') %>" in your HTML code to get a data URI
            { test: /\.(png|jpg|gif|webp|svg|zip)$/, loader: [{ loader: 'url-loader' }] },
        ],
    },

    // Webpack tries these extensions for you if you omit the extension like "import './file'"
    resolve: { extensions: ['.tsx', '.ts', '.jsx', '.js'] },

    output: {
        filename: '[name].js',
        path: path.resolve(__dirname, 'dist'), // Compile into a folder called "dist"
    },

    // Tells Webpack to generate "ui.html" and to inline "ui.ts" into it
    plugins: [
        new HtmlWebpackPlugin({
            template: './src/ui.html',
            filename: 'ui.html',
            inlineSource: '.(js)$',
            chunks: ['ui'],
        }),
        new HtmlWebpackInlineSourcePlugin(),
    ],
})

[rbuckton]

Unfortunately, this isn't enough information to go by as I'm not sure where the error is coming from since the stack trace only includes line information for the generated/bundled output.