feat: onFinishCommand handler

[petrgrishin]

Example usage:

[mleguen]

@bcoe Perhaps redundant with #1452?

Or perhaps not if #1452 only lands in yargsa...

Not incompatible, anyway.

[mleguen]

Thanks for this PR. Would you mind checking/fixing the few points @Goodluckhf and I mentioned?

[bcoe]

rather than adding additional functionality to yargs for handling async behavior, I'd rather see us combine efforts here and figure out what an async-first version of yargs might look like.

[bcoe]

@mleguen @petrgrishin if there was a stop gap between a fully async version of yargs, and something better than what we have today, I'd be open to this too; but would love for folks to collaborate and figure out what those two versions of the library are.

[mleguen]

@bcoe @petrgrishin Sure, this was the idea behind my comments on this issue.

I feel however that yargsa and this issue are complementary:

• yargs focuses on async API (ie medling with promises)
• this issue could bring the "tell application the command handler is done" feature for sync applications

I would then recommend sticking here to a standard sync API, ie:

• adding an optional done argument to the command handler
• calling onFinishCommand when done is called (if the handler uses it) or when the handler returns (if not using it)

And applications using promise-returning command handler should be encouraged to use yargsa.

What would you think of this?

[bcoe]

@mleguen your suggestion of using this work as an intermediate step towards a fully async API seems reasonable to me (my wish would be for us to get down to a healthier number of open issues on the existing yargs API, before we made the sweeping change proposed in yargsa).

@petrgrishin would you be open to addressing some of the code review brought up here?

[mleguen]

@petrgrishin Thanks!

[Goodluckhf]

LGTM

[dapplion]

Great feature! When will a version with this feature be released?

[dapplion]

@petrgrishin Small typo in the docs

[dapplion]

Typo, should be command not comand

[mleguen]

Thanks @dapplion. Mind doing a small PR to fix this typo?

[dapplion]

Thanks @dapplion. Mind doing a small PR to fix this typo?

Sure @mleguen: #1506

[bcoe]

@petrgrishin this is released now, take it for a spin and make sure it's working for you?

One thought for the future, should we potentially make onFinishCommand cause yargs to return a Promise, so that you could await a command finishing? might be a potential API improvement in the future?