stub and mock a subrotine for unit testing in perl

Question

I am trying to do unit testing of the module. I need help and information , how to mock or stub a subroutine to test package.

I do not wish to use the module I came across on cpan.

Answer 1

You an mock subs by overriding them in the following way in your test:

no warnings;
local *Foo::bar = sub {
    # do stuff
};
use warnings;

You typically want to set a variable to be checked later in your test inside your mock.

(even if I suggest using Test::MockModule, but you explicitly specified to not use it)