feat!: rework collect-unknown-options into unknown-options-as-args, providing more comprehensive functionality

[henderea]

@bcoe: since I don't seem to be able to re-open #181, I'm creating a new pull request. It turns out that the issue I was having with the command parsing after the previous pull request was that it uses an array arg, rather than the _ array. I've updated my feature from collect-unknown-options to unknown-options-as-args so that it can also cover this case.

I've tested this in the script I plan to use it in, and it works as I would expect now.

[bcoe]

@henderea thank you for digging into this, I've been dragging my feet for too long on the next release of yargs, because I was hoping to loop back around to try to dig into this issue.

I've been the victim of my of my libraries' own success these days, and have been spread a bit thin on code review I'm afraid 😦... thanks for your hard work.

@mleguen, could I perhaps loop you in to help review this.

[mleguen]

@bcoe my pleasure, but I am afraid I will not be available for a review before wednesday (my weekly OSS day at work).

[mleguen]

Wow! Just finished reading the extensive discussion in yargs/yargs#1243, #181 and #202 :-)...
Time to start reviewing!

[mleguen]

This PR sounds OK to me, apart from the small refactoring suggestion.

However, I still have one question about your former PR: why do you use Array.forEach loops instead of Array.some, which would be shorter, more readable and more efficient. If it is once again a NodeJS 6 compatibility issue, perhaps you should mark it as a compatibility hack to be removed later, as you did for Object.values?

[mleguen]

As you are using configuration['unknown-options-as-args'] && isUnknownOption(arg) rather frequently, and for the sake of readability, I would advise refactoring it into isUnknownOptionAsArg(arg):

Suggested change

	if (!args[ii].match(/^-[^0-9]/) || (configuration['unknown-options-as-args'] && isUnknownOption(args[ii]))) available++
	if (!args[ii].match(/^-[^0-9]/) || isUnknownOptionAsArg(args[ii])) available++

[henderea]

@mleguen On the topic of the forEach stuff, I was largely following the pattern of the existing code. The comment I put about Node 6 compatibility on the Object.values stuff was also copied from the existing code.

I'll make the requested refactoring to reduce the configuration['unknown-options-as-args'] && isUnknownOption(arg) into isUnknownOptionAsArg(arg) soon.

[mleguen]

@henderea OK, I can see now the source of this complicated use of Array.foreach in place of Array.some is checkAllAliases.

I will submit a PR to improve this.

[mleguen]

OK for me, thanks @henderea.

[henderea]

@mleguen: I've committed the suggested refactoring of isUnknownOptionAsArg(arg), and also have converted my 2 usages of forEach with a boolean to some. I left checkAllAliases alone, though, but I can include that in this PR if that would make it easier for everyone.

[henderea]

According to https://node.green/, it seems that support for array.some goes back just as far as array.forEach, so I think it should be fine on v6.