Bug in regex for lone short flag

[sorawee]

#1256 added a support for lone short flag.

Unfortunately, this only works correctly on short flags with one character. Short flags with multiple characters (Java-style short flags) will incorrectly create incorrect field names. For example, .option('-name') will result in a field Name, which is not in camelCase.

The reason is that this regex only matches a short flag with one character. This means a short flag with multiple characters will be categorized as a long flag. Consequently, Commander.js attempts to strip -- from -name, which is a no-op, resulting in -name. Then, the camel case conversion of -name results in Name, which is not a camel case as intended.

[shadowspawn]

Short flags with more than one character are not supported. Short flags are a dash followed by a single character. See #2211 for more details.

(Feel free to ask if you have more questions.)

[sorawee]

Thanks @shadowspawn! That makes sense. But if Java-style short flags are intentionally not supported, shouldn't .option('-name') result in an error to let users know that it is not supported (at least for now)? I think we agree that categorizing -name as a long flag should not happen, right?

[shadowspawn]

But if Java-style short flags are intentionally not supported, shouldn't .option('-name') result in an error to let users know that it is not supported (at least for now)?

For background, I didn't want to immediately break existing programs when I first found that people were specifying multi-character short flags that were not intended. So the first steps we took were to clarify README and saying this was not supported (#937 #1718).

It hasn't come up often since then, but it could be time to add an error since unsupported option syntax has come up 3 times in last month! (#2211 #2222 #2227)

I think we agree that categorizing -name as a long flag should not happen, right?

Correct. POSIX has clear rules for specifying short option and option-value, and -a AAA is the same as -aAAA. Long options allow multiple characters in name and start with two dashes.

The few applications I am familiar with that allow -multi-character-option-after-one-dash date back to when long options were first being introduced. There were a few styles being tried and it was a while before the now common --double-dash-for-long became the clear winner.

[shadowspawn]

Closing in favour of #2235, adding an error for short flag longer than one character