Perl Testing 101

Made for work.

Transcript

1. Perl Testing 101
   Craig Treptow, August, 2013
   

   View Slide

2. Goal
   Isolate each part of a program and show that
   the individual parts are correct.
   Unit Tests
   

   View Slide

3. Benefits
   ● Find problems earlier
   ● Facilitate code changes
   ○ Help ensure changes did not affect other behavior
   ● Makes integration testing easier
   ● Code becomes “self documenting”
   ○ Just look at the tests
   Unit Tests
   

   View Slide

4. Reality
   ● They do not “prove” software is correct
   ● They can be
   ○ wrong
   ○ hard to set up
   ● They do
   ○ increase programmer confidence
   ○ need to be treated like “real code”
   Unit Tests
   

   View Slide

5. What is test code?
   It’s just Perl code:
   #!/usr/bin/perl -w
   print "1..1\n";
   print 1 + 1 == 2 ? "ok 1\n" : "not ok 1\n";
   Since 1 + 1 is 2, it prints:
   1..1
   ok 1
   Perl Testing
   

   View Slide

6. 1..1
   ok 1
   This says:
   ● I’m going to run 1 test
   ● The test passed
   Perl Testing
   

   View Slide

7. Writing that kind of code would get tedious.
   So, start with Test::Simple:
   #!/usr/bin/perl -w
   use Test::Simple tests => 1;
   ok( 1 + 1 == 2 );
   That runs the same test as before.
   Perl Testing
   

   View Slide

8. Want more tests?
   #!/usr/bin/perl -w
   use Test::Simple tests => 2;
   ok( 1 + 1 == 2 );
   ok( 2 + 2 == 5 );
   Run the test:
   perl simple.t
   Produces:
   1..2
   ok 1
   not ok 2
   # Failed test (test.pl at line 5)
   # Looks like you failed 1 tests of 2.
   Perl Testing
   

   View Slide

9. Before we go on:
   a few conventions
   ● Test files are kept in folders called ‘t’
   ● Test files are named .t
   ○ 00-.t
   ○ 10-.t
   ○ 20-.t
   There aren’t “rules”, it’s Perl!!
   Perl Testing
   

   View Slide

10. Test::Simple
    ● Only provides ok()
    ● Can be awkward
    ○ Can’t tell what you got for a result
    ○ Only True/False (ok/not ok)
    There is hope...
    Perl Testing
    

    View Slide

11. Test::More
    ● ok(), is(), isnt()
    ● like(), unlike()
    ● cmp_ok(), can_ok(), isa_ok()
    ● use_ok(), require_ok()
    ● is_deeply()
    ● eq_array(), eq_hash(), eq_set
    Perl Testing
    

    View Slide