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multi sub todo($reason, $count = 1)

Sometimes tests just aren't ready to be run, for instance a feature might not yet be implemented, in which case tests can be marked as todo. Or it could be the case that a given feature only works on a particular platform - in which case one would skip the test on other platforms.

Mark $count tests as TODO, giving a $reason as to why. By default only one test will be marked TODO.

sub my-custom-pi { 3 };
 
todo 'not yet precise enough';         # Mark the test as TODO. 
is my-custom-pi(), pi, 'my-custom-pi'; # Run the test, but don't report 
                                       # failure in test harness. 

The result from the test code above will be something like:

not ok 1 - my-custom-pi # TODO not yet precise enough 
# Failed test 'my-custom-pi' 
# at test-todo.t line 7 
# expected: '3.14159265358979' 
#      got: '3' 

Note that if you todo a subtest, all of the failing tests inside of it will be automatically marked TODO as well and will not count towards your original TODO count.