In Google Chrome extensions before manifest v3 I could divide background.js into multiple scripts. And to load all scripts to be visible in background.js I only need to to put them in array in manifest like this:
"background": {
"scripts": ["helpers/countHelper.js", "helpers/networkHelper.js", "background/main.js"],
}
With this above sintax, all scripts will be merged into one file.
Now in documentation how to use manifest v3, they wrote:
Replace background.page or background.scripts with background.service_worker in manifest.json. Note that the service_worker field takes a string, not an array of string.
Cause background in manifest can't take multiple scripts, how to divide background script into multiple scripts. Also import syntax is not allowed as I know.