WIP: Reject excess arguments by default

[shadowspawn]

Pull Request

Problem

By default, excess arguments are silently ignored. Checking manually is a bit tricky.

See: #259 #749 #1000 #1268

Solution

• add a check for excess arguments before calling action handler
• .allowExcessArguments() is like .allowUnknownOption() to suppress the new error
• .command('*') arguments are not checked to maintain legacy behaviour

Other changes:

• switch action handler from trailing parameters of "options/command" and undocumented "extraArgs", to "options/command" and "command". This will hopefully make it easier to switch to safer options stored separately.

To Do

• command:* listener
• single commands with no action handler
• default command
• refine messaging (not happy with "excess")

TypeScript, tests, README et al

ChangeLog

• excess arguments now cause an error (WIP: Reject excess arguments by default #1399)

[shadowspawn]

I tried doing a couple of things at once here which I am thinking of as somewhat related. However, they are individually complicated and not certain to work out well. I'll close this and have another go at one thing at a time.

See #1407

[shadowspawn]

I am finding this is breaking quite a lot of my unit tests (due to lazily not declaring arguments) and not picking up actual problems. I think for Commander v7 it would be better to make this an opt-in behaviour that is inherited to subcommands (so can easily turn it on for whole program). Command 7 has breaking changes with options storage and action handler parameters, so plenty else for users to deal with!

I'll think a bit more and do a PR for consideration.