Print help only when there are no arguments

[yeonhoyoon]

knex cli should print help only when there are no arguments.
current implementation always prints help even when given correct arguments, such as knex migrate:status.
the correct way to check argument length is via process.argv.
reference: https://github.com/tj/commander.js/#outputhelpcb

[timorthi]

+1 also running into this, looks like a regression from #3604

[kibertoad]

I'll take a look tomorrow, thanks. One quick note: could you please add cli-testlab-based test for this?

[yeonhoyoon]

OK, but I'm not familiar with cli-testlab, so I will need some time to look into it.

[kibertoad]

@yeonhoyoon Here is a super simple example: https://github.com/knex/knex/blob/master/test/cli/version.spec.js

and you can check other files in same directory if you'd need more than that

[yeonhoyoon]

@kibertoad
Thanks for your feedback, I added some specs to test help command.
There wasn't an assertion helper in the cli-testlab for expecting the output to not include a given string, so I used the raw stdout variable instead to test the desired behavior.

[kibertoad]

Much appreciated!

There are linting errors in the test:

/home/travis/build/knex/knex/test/cli/help.spec.js
   6:7  error  'cliPkg' is assigned a value but never used  no-unused-vars
  30:7  error  'expect' is not defined                      no-undef

After those are fixed, this can be merged :)

[kibertoad]

@yeonhoyoon BTW, thank you for mentioning missing functionality in cli-testlab. I've added notExpectedOutput parameter and published 1.9.0, but it's a small thing, feel free to update it or leave as it is.

[yeonhoyoon]

@kibertoad
Apologies for leaving unused variables in the code, and thanks for quickly adding features to cli-testlab. I've changed the tests to use the newly added functionality.
Please let me know if you have any other feedback.

[kibertoad]

Thanks! <3

[kibertoad]

Released in 0.20.8