Yes shift is intended to be used in this way.

Anyway if you have doubts, as i frequently have, add a firendly print statement as basic debug tool:

sub run_tests{

  my $browser = shift;
  print "The sub 'run_test' received [$browser] as parameter\n";
[download]

if your program handles also other parameter maybe you can have a debug one so you can fill your programs of stuff like:

  print "The sub 'run_test' received [$browser] as parameter\n"   if  
+ $debug;
[download]

L*