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When I run npm run build in my react app I get the following warning: static/js/widget.js contains invalid source map .

When I remove the UglifyJs settings in my webpack config the build process passes without any warnings.

My Webpack config (only parts which are relevant regarding the sourcemap):

// Source maps are resource heavy and can cause out of memory issue for large source files.
const shouldUseSourceMap = process.env.GENERATE_SOURCEMAP !== 'false';
module.exports = {
  // Don't attempt to continue if there are any errors.
  bail: true,
  mode: 'production',
  // We generate sourcemaps in production. This is slow but gives good results.
  // You can exclude the *.map files from the build during deployment.
  devtool: shouldUseSourceMap ? 'source-map' : false,
plugins: [
    new UglifyJsPlugin({
      uglifyOptions: {
        sourceMap: shouldUseSourceMap,
        warnings: false,
        compress: {
          comparisons: false
        output: {
          comments: false,
          ascii_only: true
                I am also facing the same issue and I figured out that, with Webpack 3 and Ugify I dont see this issue, whereas if I am using Webpack4 the warning is thrown. Trying to dig further. Let me know if you found some solution
– coderHASH64codingHASH46code
                Apr 30, 2020 at 15:23
        
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