fix: strict should fail unknown arguments

[jly36963]

Addresses: #1861

As always, let me know if I need to change/add/fix anything.

Issue

This should fail:

const argv = yargs.strict().parse('foo');
console.log(argv) // { _: [ 'foo' ], '$0': 'example.js' }

Neither unknownArguments nor unknownCommands catch extra args when commandKeys.length is 0.

Fix

I added a block to check if there are any elements in argv that aren't in currentContext.commands. I made sure to tolerate args when yargs.demand(number) is called, when the number of args falls within the min/max range.

This shouldn't fail:

const argv = yargs.strict().demand(1).parse('foo');
console.log(argv) // { _: [ 'foo' ], '$0': 'example.js' }

Note

I don't understand the demand logic well (as it's deprecated and not in the docs), so I'm not sure if the slice in this line will always be correct:

I saw that a few other places do something similar.

[bcoe]

@jly36963 thanks for digging into this, will make an effort to review this week 👍 It's great to start squashing some of the long standing bugs.

[bcoe]

@biggianteye, @brlodi, I've published @jly36963's fix to yargs@next, mind trying it out and seeing if this approach would work for your application?

npm i yargs@next, or npm i yargs@17.0.2-candidate.

[biggianteye]

@biggianteye, @brlodi, I've published @jly36963's fix to yargs@next, mind trying it out and seeing if this approach would work for your application?

npm i yargs@next, or npm i yargs@17.0.2-candidate.

I've just tested this version with the code I used in the bug report and it is now working as expected. Thanks!

$ node index.js foo
Options:
  --help     Show help                                                 [boolean]
  --version  Show version number                                       [boolean]

Unknown argument: foo