问题
When using CommonJS modules in Node, you can detect whether a script is being run from the command line using require.main === module.
What is an equivalent way to detect whether a script is being run from the command line when using ES Modules in Node (with the --experimental-modules flag)?
回答1:
There is none - yet (it's still experimental!). Although the prevailing opinion is that such a check is a bad practice anyway and you should just provide separate scripts for the library and the executable, there is an idea to provide a boolean import.meta.main property for this purpose.
来源：https://stackoverflow.com/questions/57838022/detect-whether-es-module-is-run-from-command-line-in-node