I have this Webpack configuration:
{
output: {
libraryTarget: "system",
...
},
...
}
I'm trying to use a Web Worker. I'm using the standard Webpack 5 syntax:
new Worker(new URL('./MyWorker', import.meta.url));
Now Webpack outputs the Web Worker as a System.js module. How can I change it to something different, like ES module, without affecting the main bundle?
You can use chunkFormat to specify what the chunk formats are, workers are by default array-push, https://webpack.js.org/configuration/output/#outputchunkformat.
You can also create multiple configs with different targets for different entries.
const config = {
//
}
module.exports = (env) => {
if (env.module) {
config.entry = //path/to/index
config.output.libraryTarget = 'module'
} else {
config.entry = //path/to/worker
config.output.libraryTarget = 'umd'
}
return config
}
Then you can separately compile your web workers or chunks different from others. You can also use chunkFileName: () => along with that.
If you want to compile it in a single run, without having to run it twice using different configs, you can also manually invoke the webpack compiler with both configs.
import {Compiler} from 'webpack'
// or import webpack from 'webpack'
compiler.run(config)
compiler.run(config2)
Then you can run both of them at the same time and compile everything.
Another possible option is enabledChunkLoadingTypes, https://webpack.js.org/configuration/output/#outputenabledchunkloadingtypes, which will allow you to specify the available loading types for chunks which webpack will automatically use based on the entry function. I've never used that myself so I don't know if that'll work but it's something you can try.