Webpack not loading sourcemap from local library

I have a library (simple helper functions) that is bundled with esbuild:

esbuild.js

esbuild.build({
  entryPoints: ['src/index.ts'],
  bundle: true,
  sourcemap: true,
  minify: true,
  out: 'dist',
  format: 'cjs',
  target: ['es6']
})

With the above, i see

/dist
    /user
        profile.d.ts
        settings.d.ts
        history.d.ts
    /invoice
        latest.d.ts
        quarter.d.ts
    index.d.ts
    index.js
    index.js.map

In my consuming app, i able able to import and use the above lib functions just fine. However debugging in the browser, the library code is minified/hard to read.

I am trying to get the consuming apps webpack.config to load either the raw src code from the lib or sourcemaps.

webpack.config.js:

module.exports = (env, argv) = {
  return {
    devtool: 'source-map',
    module: {
        rules: [
            {
                // Match js, jsx, ts & tsx files
               test: /.[jt]sx?$/,
               loader: 'esbuild-loader',
               options: {
                   // JavaScript version to compile to
                   loader: 'tsx',
                   target: 'es2015',
                   sourcemap: true
               }
               exclude: /node_modules/
            }               
        ]
    },
    resolve: {
         extensions: ['.tsx', '.ts', '.js', '.jsx']
    },
    target: ['web', 'es5'],
    optimization: {
        minimizer: [
            new ESBuildMinifyPlugin({
                target: 'es2015'
            })
        ]
    }
  }
}