Add support for multiple aliases

[shadowspawn]

Pull Request

See #531

Problem

Some people would like to add more than one alias for a command, but not have them all visible in the help.

Solution

Allow adding multiple aliases. Only display the first one in the built-in help, and leave any mention of the rest up to the caller.

This is intended to be backwards compatible. There is a small change from v5.0 behaviour, calling .alias() when there is no alias will now return undefined instead of null, but seems unlikely to affect much code and can be made fully backwards compatible if necessary.

To provide public access to the possibly multiple aliases, added .aliases() which works with array rather than string.

ChangeLog

• add support for multiple aliases

[kodie]

This is awesome!

[shadowspawn]

Changes: added .aliases() mainly to give public access to full list of aliases (e.g. for code adding command-line completion).

[shadowspawn]

I'll leave PR in draft for a few more days for any other feedback.

Thanks @kodie and @victornpb and @abetomo

[shadowspawn]

No further feedback. Moving out of draft.

I have deliberately not added to README for now, hopefully anyone who wants the feature will be able to find it easily enough, and the JSDoc and TSDoc cover the support for multiple aliases.

[abetomo]

Awesome!

[shadowspawn]

Included in Commander v5.1 which has been released.

https://github.com/tj/commander.js/releases/tag/v5.1.0

[viceice]

This is blocking us from upgrading, since we use aliasses as an option.

Wha'ts the best compatible way to solve this.

[shadowspawn]

Sorry for the clash @viceice

See the section in the README about avoiding name clashes, and have a look at storeOptionsAsProperties and passCommandToAction:

• https://github.com/tj/commander.js#avoiding-option-name-clashes

[viceice]

@shadowspawn Ok, thanks for the info. Works with the suggested changes.