Perl Testing 101

Made for work.

Transcript

1. Perl Testing 101 Craig Treptow, August, 2013
2. Goal Isolate each part of a program and show that the individual parts are correct. Unit Tests
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
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
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
6. 1..1 ok 1 This says: • I’m going to run 1 test • The test passed Perl Testing
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
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
9. Before we go on: a few conventions • Test files are kept in folders called ‘t’ • Test files are named <something>.t ◦ 00-<test prerequisites>.t ◦ 10-<module name>.t ◦ 20-<module name>.t There aren’t “rules”, it’s Perl!! Perl Testing
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
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