I need to test a feature that includes this line:
if $translate-nl && $*DISTRO.is-win
I have tried to reassign a value to $*DISTRO,
$*DISTRO='Windows 10';
but it says:
Cannot modify an immutable Distro (debian (9.stretch))
$*DISTRO
is a dynamic variable, and it makes sense that it's not modified. That said, is there any other way that code can be tested (other than going to Windows, of course)
my $*DISTRO = ...
Hopefully modifying the original is unnecessary. It's generally unreasonable action-at-a-distance -- almost certainly so if someone has arranged for it to be an immutable value. This is the reason why global variables got such a bad reputation.
To elaborate on raiph's answer: the *
in $*DISTRO
marks it as a dynamic variable. You can re-declare it any scope, and code called from there will see the redeclared value:
{
my $*DISTRO = ...;
# coded called from here sees the redeclared value
}
# code called from here sees the original value
Now, the question remains, what do you put in place of these pesky ...
?
In the simplest case, a mock that just has whatever the code under test needs:
{
my class Distro { has $.is-win }
my $*DISTRO = Distro.new( :is-win );
# call your test code here
}
If the code needs more attributes in Distro
, just add them to the mock Distro
class.
If the code needs a "real* Distro
object, for some reason, you can instantiate the built-in one. The constructor .new
isn't really documented, but the source code makes it pretty obvious what arguments it expects.
OK, I got the answer relatively fast. $*DISTRO
is actually a read-only alias of PROCESS::<$DISTRO>
So we only need to do:
my $*DISTRO = Distro.new(:is-win,:release<11>,:path-sep('|||'),:auth<unknown>,:name<mswin32>,:desc<Test>,:version<v11>);
say $*DISTRO.is-win; #OUTPUT: «True»