Problem

I have three git aliases defined in .gitconfig (with an external bash script defining a function called diff-lines):

    [alias]
        diffc = diff --cached
        diffnw = diff -w --ignore-cr-at-eol --ignore-all-space
        diffln =!bash -c 'source $HOME/.bash_functions/diff-lines && git diff | diff-lines'

How can I define 'diffln' such that I can tell it which version of my diff aliases to use?

I'm looking for something to prevent me from having to define each version similar to:

    diffcln =!bash -c 'source $HOME/.bash_functions/diff-lines && git diffc | diff-lines'
    diffnwln =!bash -c 'source $HOME/.bash_functions/diff-lines && git diffnw | diff-lines'
    diffcnwln =!bash -c 'source $HOME/.bash_functions/diff-lines && git diffnw --cached | diff-lines'
    etc...

Solution

Thanks to @KamilCuk for the solution. I needed to include something/anything after the alias, and also enclose the whole alias in double quotes.

The full working command is this (with a default option to use git diff if no argument is provided):

    diffln ="!bash -c 'source $HOME/.bash_functions/diff-lines && if ((!$#)); then set -- diff; fi && git $@ | diff-lines' _"

Previous Attempts

I have tried this:
diffln =!bash -c 'source $HOME/.bash_functions/diff-lines && git $@ | diff-lines'
and called via:
$ git diffln diffc but it just gave me the default git options as if I was only calling $ git