Fix for #22: stop error from test command

[tomsaleeba]

Fixes #22.
I'm not sure if this is the behaviour you want but at least it gets rid of that error from test

[brigand]

Doesn't this throw from the argv access if there are no arguments?

[tomsaleeba]

Yeah, it throws from here:

fast-nvm-fish/nvm.fish

Line 8 in ff47b8d

set -l command $argv[1]

A simple test case is this script:

#!/usr/bin/fish
echo 'before'
set -l c $argv[1]
if test $c = 'use'
  echo 'yep, use'
end
echo 'after'

Assume we save it as blah.fish and it explodes when you try to access that non-existant index of $argv, like you say:

$ fish blah.fish asdf
before
after

$ fish blah.fish
before
test: Missing argument at index 2
after

My goal is to stop that error message. Setting a default "command" has the added bonus of making the script more user friendly; you can run it with no args happily.

[brigand]

You need to use (count $argv) and not read the item if it's 0.

[tomsaleeba]

How about this approach: https://github.com/tomsaleeba/fast-nvm-fish/commit/26bef18115ef6aae190f6f491821081e58a7c99f#diff-5aa7c1aafb1d525d781f1c83ca10e0c2

It achieves the same goal as this PR but goes about it a bit differently. It does what you mentioned by branching based on the result of the count of the whole argv list, not the element at index 1.