Mock a command that's ran with command?

[dideler]

How would you mock a command that's ran with command?

Given a function that's under test

function foo
  command rm bar
  command ls
end

And you want to mock ls for example.

Doing mock ls 0 "echo foo" doesn't work, and mocking command is not possible because it's blacklisted.

[Markcial]

That is a good question, due to some limitations i am unable to mock some functions or commands, being command one of those.
Also I cannot mock the "runtime" created functions, so if you place a function inside your function in a nested scope, being that nested function the last one, it disables all the others.

I have to add some small features, like the possibility to use a custom function instead of a evaluated string, but other features might be a good call to arms if you want to help. Some help would be really nice.

If you have any idea or want to fiddle around and get in a point further where i did get i would be really grateful.

[dideler]

I see now why mock has a blacklist, because fish has reserved these names.

In fish 2.5.0 (but not 2.6.0 due to a regression), when you try to override a builtin

function: The name 'command' is reserved,
and can not be used as a function name

I'm not really sure how we can get around this limitation.

There used to be a --shadow-builtin option for functions but it was controversial and short-lived.