Config options target and supported are not working

[georgolden]

Bug:

Config: https://github.com/oldbros/shiftjs/blob/main/scripts/build.mjs

After compilation: https://github.com/oldbros/shiftjs/blob/main/dist/shift.cjs

It is clear, that both target and supported options are ignored completely during build. Code is es2015 no matter what

[evanw]

I haven't investigated this yet but I'm guessing this is done for internal esbuild-specific reasons and is not related to target and supported at all (for more information see #2416 and #2889). The target and supported settings tell esbuild that it can assume a feature is supported, but that's different from forcing esbuild to not transform syntax. There is no API for forcing esbuild to not transform syntax. I would ideally like to improve the output here but that's tricky due to the current design of esbuild's class transformation code. I'm labeling this suboptimal-output because this is intentional behavior and is not a bug.

[georgolden]

@evanw ok. thanks. I hope it will be refactored somewhere in the future. I like esbuild for config simplicity