CPAN Module Distributions

NOTE Numbers are added to the front of the t/*.t test script names 

because make test runs the test files in sorted order. By ordering your 

test scripts, you can test basic functionality at the start of the test run 

and reduce the time it takes to detect simple errors.

Another way to improve your testing is to use the Test::More module instead of 

Test. Test::More

14

 lets you write your tests in such a way that failing tests provide 

much more information. For example, consider a test case that verifies that the 

count() function returns a count of its arguments:

ok(Data::Counter::count( foo ,  bar ) == 2);

If this test fails, then all you're told is that the test failed.

If instead you used Test::More's is() function, then you'll get a much more 

useful error:

is(Data::Counter::count( foo ,  bar ), 2);

The is() function takes two arguments the operation to be tested and the 

expected value. If count() returns 3 instead of 2, then the test will fail with the 

following message:

#     Failed test (t/testname.t at line 3)

#          got:  3 

#     expected:  2 

Armed with the expected results and the actual return value, you may not even 

need to look at the test script to start debugging. Test::More includes testing 

functions for applying regular expressions (like()), comparing complex data 

structures (eq_array(), eq_hash(), eq_set(), and is_deeply()), and examining 

objects (can_ok() and isa_ok()). Test::More also contains support for skipping tests 

when they are known to fail under certain environments and marking tests as todo

items that are not expected to pass. See the Test::More documentation for details 

on all this and . . . well, more!

14. Written by Michael Schwern and available on CPAN

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