feat: Add .parserConfiguration() method, deprecating package.json config

[jean-emmanuel]

A non-breaking proposal to address #1259 and #1248, it might be incomplete so please amend if needed.

[bcoe]

@jean-emmanuel this looks great, we should add a test though 👍

[jean-emmanuel]

I just pushed 2 tests, what do you think ?

[jean-emmanuel]

Travis' fail seems unrelated by the way.

[evocateur]

Really excited for this!

One small tweak and we're good to go.

[bcoe]

@evocateur @jean-emmanuel where does this stand? would love to land the work; I'm thinking perhaps we land this as a major, and then in the next major actually retire it?

[evocateur]

I think this is good to go now, @bcoe

[evocateur]

This strikes me as semver-minor, with removal in the next major. If there are other semver-majors waiting in the wings, it could certainly go along with that.

[bcoe]

@evocateur @jean-emmanuel, @isaacs just pointed this out to me:

https://nodejs.org/api/util.html#util_util_deprecate_fn_msg_code

☝️ Node.js has a built in deprecate message that debounces.

[bcoe]

let's use this -- @evocateur there's some somewhat finicky breaking changes landing in yargs-parser, so I'm a bit tempted to land it in a major (the ones you reviewed around handling of missing right-hand values).

[evocateur]

Thanks for your patience @jean-emmanuel, do you have time to migrate to util.deprecate()?

[evocateur]

@bcoe As @jean-emmanuel rightly pointed out, util.deprecate() isn't appropriate for something that is called every time yargs parses arguments.

[evocateur]

Thanks @jean-emmanuel!

[jean-emmanuel]

woohooo !

[bcoe]

this is now available in yargs@13.1.0.

[plroebuck]

Uh, yeah. @bcoe?
Re: mochajs/mocha#3742

• yargs-13.0.0 mentions in "breaking changes" that Node-6 was being dropped (though "package.json" still shows "node": ">=6"). Did you or didn't you?
• Mocha will support Node-6 at least until end-of-life, so cannot upgrade to yargs-13 yet if support dropped (or will be without another semver-major).
• Yargs-13 introduced yargs.parserConfiguration, but no backport to yargs-12 available.
• Users using yargs-13 now get deprecation warning, with no visible means to address the problem from Mocha via yargs-12.

Recommendations?

[plroebuck]

BTW, your documentation shows:

yargs.parserConfiguration({
  "yargs": {
    "short-option-groups": true,
    "camel-case-expansion": true,
    "dot-notation": true,
    "parse-numbers": true,
    "boolean-negation": true
  }
})

but "test/fixtures/configured-bin.js" shows:

var argv = require('./yargs/index.js')
  .parserConfiguration({'dot-notation': true})
  .help('help')
  .version()
  .argv

[bcoe]

• yargs-13.0.0 mentions in "breaking changes" that Node-6 was being dropped (though "package.json" still shows "node": ">=6"). Did you or didn't you?

@plroebuck we can no longer promise that Node >=6 will continue to be supported in yargs 13; one reason being flakiness we were seeing in CI/CD with the current combination of npm and Node.js shipped on 6.x. The engine field was just missed being updated.

• Mocha will support Node-6 at least until end-of-life, so cannot upgrade to yargs-13 yet if support dropped (or will be without another semver-major).

We would be open to back-porting this change-request, and security patches back to 12.x.

BTW, your documentation shows...

☝️ I believe the documentation is wrong.

@plroebuck could you open a few issues rather than commenting on a closed issue, the odds of us losing track of your comment are high.

@jean-emmanuel interested in back-porting this to yargs@12.x without the deprecation warning. To do so we would create a new 12.x branch, from the point at which we released 8789bf4, and cherry-pick create a pull request against this branch.