Angular CLI natively doesn’t support this.
There are other solutions, including further processing with other tooling after Angular CLI finishes doing its thing, but this will hinder or remove the debugging capabilities Angular provides out-of-the-box.
As the ng eject command is also being deprecated, the option to reconfigure webpack is not as attractive as it used to be. However, that is still technically a possibility.
My solution:
The best solution I have found is the ngx-build-plus plugin, which can be found at https://github.com/manfredsteyer/ngx-build-plus or added to a project via the ng add ngx-build-plus Angular-CLI command currently. Once installed, it provides additional configuration options for building, including the --single-bundle true flag that can be added to an ng build or ng serve command.
With that flag, a main.js file and a main.js.map file are created, already referenced in the HTML, and it’ll just run like that properly out of the box, with full source mapping and debugging.