Allow to configure source map type

packages/react-scripts/config/webpack.config.prod.js

@@ -31,6 +31,7 @@ const publicPath = paths.servedPath;
 const shouldUseRelativeAssetPaths = publicPath === './';
 // Source maps are resource heavy and can cause out of memory issue for large source files.
 const shouldUseSourceMap = process.env.GENERATE_SOURCEMAP !== 'false';
+const sourceMapType = process.env.SOURCEMAP_TYPE;
 // `publicUrl` is just like `publicPath`, but we will provide it to our app
 // as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
 // Omit trailing slash as %PUBLIC_URL%/xyz looks better than %PUBLIC_URL%xyz.
@@ -64,7 +65,7 @@ module.exports = {
   bail: true,
   // 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,
+  devtool: shouldUseSourceMap ? (sourceMapType || 'source-map') : false,
   // In production, we only want to load the polyfills and the app code.
   entry: [require.resolve('./polyfills'), paths.appIndexJs],
   output: {