I wonder if it is worth supporting both formats, string is more concise for simple use cases and object is better for white space paths and such

cc @lucasfernog

supporting both formats is what we do :) use an enum with serde(untagged)

@anatawa12 sorry for the inconvenience, could you add support for both? and add a note in docs that users should use the object format if their binary or arguments have spaces.

OK.
Should support quote in string notation for whitespaces? or use old simple parser with split(' ')?

use old simple parser, and just add a note in docs, thanks

I added string form support in 53e285a.

Since string format is only for simpler config file, I added parsing logic in cli module and bundler module have single object form as input.