Re: Fixtures
--- Kirrily Robert [EMAIL PROTECTED] wrote: Does anyone here understand fixtures as a testing concept, and could they please explain it to me in a Perlish way? At least half of what I've heard described is what I usually achieve with a t/data/ directory, and another half is what I'd do by writing a specialized Test::Builder-based module. A test fixture establishes a known state of a system. For example, when running with Test::Class, you can use setup and teardown methods which run before and after every test to load test data in a database, set up temp files, or do anything necessary to start a known, stable state and later do transaction rollbacks, clean up temp files and so on. One of the reasons randomizing test runs is important is because they can shake out bugs in the code when you have strange ordering dependencies, fail to clean up temp files, alter global state, etc. Test fixtures can make finding such code errors even more reliable because they guarantee (to the extent that they're not buggy) that every set of tests which runs has, if you will, the same starting point. Cheers, Ovid -- Buy the book -- http://www.oreilly.com/catalog/perlhks/ Perl and CGI -- http://users.easystreet.com/ovid/cgi_course/
Re: Fixtures
On Feb 12, 2007, at 10:35 PM, Kirrily Robert wrote: Does anyone here understand fixtures as a testing concept, and could they please explain it to me in a Perlish way? One definition of a fixture comes from the Fitnesse system which is a framework for collaboration on acceptance testing. Fitnesse makes it really easy for non-programmers to add assertions to a set of tests. Typically the programmers provide a Fixture for each category of testing and the non-programers edit a wiki page to add rows to a table. Each row in the table on the wiki page is interpreted as a assertion and when you click the test button the Fitnesse framework executes the Fixture code, passing it the data from each row in the table. It's much easier to see than to explain: http://fitnesse.org/FitNesse/FitNesse/FixtureCode --- Matisse Enzer [EMAIL PROTECTED] http://www.matisse.net/ - http://www.eigenstate.net/
Re: Fixtures
--- Matisse Enzer [EMAIL PROTECTED] wrote: Typically the programmers provide a Fixture for each category of testing and the non-programers edit a wiki page to add rows to a table. Each row in the table on the wiki page is interpreted as a assertion and when you click the test button the Fitnesse framework executes the Fixture code, passing it the data from each row in the table. It's much easier to see than to explain: http://fitnesse.org/FitNesse/FitNesse/FixtureCode Really? :) java.lang.NullPointerException fitnesse.wikitext.WidgetBuilder.addChildWidgets(Unknown Source) fitnesse.wikitext.WidgetBuilder.addChildWidgets(Unknown Source) fitnesse.wikitext.WidgetBuilder.addChildWidgets(Unknown Source) fitnesse.wikitext.WidgetBuilder.addChildWidgets(Unknown Source) Cheers, Ovid -- Buy the book -- http://www.oreilly.com/catalog/perlhks/ Perl and CGI -- http://users.easystreet.com/ovid/cgi_course/
Re: Fixtures
On Tuesday 13 February 2007 08:24, Ovid wrote: Really? :) java.lang.NullPointerException Oh please, everyone knows Java doesn't have pointers! -- c OT - there are a lot of definitions of fixtures. The best I've found is stuff tests share, which is exactly what Skud said.
Re: Fixtures
On Tue, Feb 13, 2007 at 09:20:29AM -0800, chromatic wrote: On Tuesday 13 February 2007 08:24, Ovid wrote: Really? :) java.lang.NullPointerException Oh please, everyone knows Java doesn't have pointers! Of course it does. They may not be accessible to the programmer due to the design of the bytecode, but they exist. On a recent JRE I can even figure out the rough size of the stack frame using a trick to get to a very limited piece of access to the pointers. Ben
Re: Fixtures
[EMAIL PROTECTED] wrote: On Tue, Feb 13, 2007 at 09:20:29AM -0800, chromatic wrote: On Tuesday 13 February 2007 08:24, Ovid wrote: Really? :) java.lang.NullPointerException Oh please, everyone knows Java doesn't have pointers! Of course it does. They may not be accessible to the programmer due to the design of the bytecode, but they exist. Ben, please calibrate your sarcas-o-meter by setting one liner from chromatic to 100 and going from there. ;)
Re: Fixtures
# from Ovid # on Tuesday 13 February 2007 01:16 am: --- Kirrily Robert [EMAIL PROTECTED] wrote: Does anyone here understand fixtures as a testing concept, and could they please explain it to me in a Perlish way? At least half of what I've heard described is what I usually achieve with a t/data/ directory, and another half is what I'd do by writing a specialized Test::Builder-based module. A test fixture establishes a known state of a system. For example, when running with Test::Class, you can use setup and teardown methods which run before and after every test to load test data in a database, set up temp files, or do anything necessary to start a known, stable state and later do transaction rollbacks, clean up temp files and so on. Good description, but I think teardown is (at least conceptually) part of setup. How about, a thing into which the item under test gets inserted? The c2 wiki (http://c2.com/cgi/wiki?TestFixture) has it as analogous to an electronics test fixture. They should probably include light fixture as a very simple metaphor. If you're testing electric lamps (non-engineers usually call them light bulbs), you screw them into a test fixture, plug it in, and flip the switch. This emulates the production environment, but with known variables (input voltage, surface reflectance, etc) so you can measure the luminosity and verify that it is within spec. So, the fixture gives you the surrounding environment (and/or related inputs, overrides CORE::GLOBAL::time and whatever), then your test just involves one chunk of code and the direct inputs to it. e.g. You might have several fixtures, each of which creates an object with a known set of attributes, then the tests call a method call on that object with various parameters. --Eric -- Speak softly and carry a big carrot. --- http://scratchcomputing.com ---
Re: Fixtures
On 2/12/07, Kirrily Robert [EMAIL PROTECTED] wrote: Does anyone here understand fixtures as a testing concept, and could they please explain it to me in a Perlish way? In terms of etymology only, it was explained to me that the term fixture comes from the idea of testing hardware components. You want the environment to change as little as possible from component to component, thus you build a fixture so that you may plug the component in, test it, unplug it, and move onto the next. -- Ian Langworth
RE: Fixtures
Thanks all, especially Ovid who came closest to answering the actual question, i.e. can someone explain it to me *in a perlish way*. Ovid's example used Test::Class's setup/teardown; would anyone else be able to provide confirm that I'm making sense in the following Test::Harness/Test::More style example: 1. Assume a test file t/foo.t 2. Assume a directory t/data (or t/fixtures if you will -- I just call it data in my own tests). 3. Create a file t/data/foo.yml (or whatever data format) containing the data needed by the tests in foo.t 4. At the beginning of foo.t, load data/foo.yml into whatever data structure (memory, SQLite, real database, etc) 5. Run tests against foo.t 6. When foo.t exits, tear down the data created in step 4. Yes? In other words fixtures is just a jargony name for t/data/, right? And, is the above setup/teardown stuff right, or would you do it before each individual test? That would seem to be nearly nonsensical, but then, I've seen stupider ideas. My earlier comment about Test::Builder-based test modules was that some of the fixtures stuff I've seen used repeated code chunks to go over the contents of foo.yml, for instance doing validation runs against each record, and it looked to me as if the Perlish way to do that is to write a test module that provides record_is_valid() and related stuff. As I understand it now, this isn't actually part of fixtures conceptually, it's just something that one might tend to see near fixtures. K.
RE: Fixtures
Ruby has a nice description at http://manuals.rubyonrails.com/read/chapter/26 To quote Fixtures is a fancy word for ‘sample data’. Fixtures allow you to populate your testing database with predefined data before your tests run. Think about how something like Test::MockDBI's set_retval_arry() or set_retval_scalar() can be setup to return specific result sets for specific SQL queries - fixtures could be a nice way to modele creating this sample query result set. L -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Tuesday, 13 February 2007 5:36 PM To: perl-qa@perl.org Subject: Fixtures Does anyone here understand fixtures as a testing concept, and could they please explain it to me in a Perlish way? At least half of what I've heard described is what I usually achieve with a t/data/ directory, and another half is what I'd do by writing a specialized Test::Builder-based module. K. -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.411 / Virus Database: 268.17.33/678 - Release Date: 9/02/2007 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.411 / Virus Database: 268.17.33/678 - Release Date: 9/02/2007 ** IMPORTANT The contents of this e-mail and its attachments are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you received this e-mail in error, please notify the HPA Postmaster, [EMAIL PROTECTED], then delete the e-mail. This footnote also confirms that this e-mail message has been swept for the presence of computer viruses by Ironport. Before opening or using any attachments, check them for viruses and defects. Our liability is limited to resupplying any affected attachments. HPA collects personal information to provide and market our services. For more information about use, disclosure and access see our Privacy Policy at www.hpa.com.au **
RE: Fixtures
--- Kirrily Robert [EMAIL PROTECTED] wrote:
2. Assume a directory t/data (or t/fixtures if you will -- I just
call
it data in my own tests).
3. Create a file t/data/foo.yml (or whatever data format) containing
the
data needed by the tests in foo.t
4. At the beginning of foo.t, load data/foo.yml into whatever data
structure (memory, SQLite, real database, etc)
5. Run tests against foo.t
6. When foo.t exits, tear down the data created in step 4.
Yes? In other words fixtures is just a jargony name for t/data/,
right?
Pretty much, for the common sense that the term is often used (though
as noted people tend to have different definitions.
And, is the above setup/teardown stuff right, or would you do it
before
each individual test? That would seem to be nearly nonsensical, but
then, I've seen stupider ideas.
Well, many languages consider a 'test' to be a set of asserts. So with
Test::Class, the following would be considered *one* test by a Java
programmer but *four* tests by a Perl programmer:
sub customer_name : Tests(4) {
my $test = shift;
my $class = $test-testing_class;
ok my $cust = $class-new('bob'),
'Creating a new customer should work';
isa_ok $cust, $class, '... and the object it returns';
can_ok $cust, 'name';
is $cust-name, 'bob',
'... and it should return the correct name';
}
That's one of the reasons for conceptual mismatches for different
programmers.
My earlier comment about Test::Builder-based test modules was that
some
of the fixtures stuff I've seen used repeated code chunks to go over
the
contents of foo.yml, for instance doing validation runs against each
record, and it looked to me as if the Perlish way to do that is to
write
a test module that provides record_is_valid() and related stuff. As
I
understand it now, this isn't actually part of fixtures
conceptually,
it's just something that one might tend to see near fixtures.
Well, here's one way I do test fixtures with regular .t programs:
use Test::More tests = 5;
use Our::Test::Database;
my ( $class, $dabase );
BEGIN {
$database = Our::Test::Database-new;
$class = 'Customer';
use_ok $class or die;
}
ok my $cust = $class-new('bob'),
'Creating a new customer should work';
isa_ok $cust, $class, '... and the object it returns';
can_ok $cust, 'name';
is $cust-name, 'bob',
'... and it should return the correct name';
'Our::Test::Database' starts with something like (can't recall the
exact syntax) and use Template::Toolkit:
DROP DATABASE [% test_database %] if exists;
CREATE DATABASE [% test_database %];
USE [% test_datbase %]
# table definitions
Note that much of the above is simply handled for me with Test::Class,
but I tend to use Test::Class for OO tests and .t files for procedural
code. It seems a better conceptual match.
Later, the 'Our::Test::Database' has a DESTROY method which drops the
database. At the beginning and end of every .t file, the database is
created from scratch and destroyed.
You can also create a test helper module which can populate the
database with sample data (or at least static data which should always
exist), though this means that the programmer looking at a test doesn't
immediately see what data's in the database.
Cheers,
Ovid
--
Buy the book -- http://www.oreilly.com/catalog/perlhks/
Perl and CGI -- http://users.easystreet.com/ovid/cgi_course/
Re: Fixtures
Hi!
On Wed, Feb 14, 2007 at 09:46:19AM +1100, Kirrily Robert wrote:
example used Test::Class's setup/teardown; would anyone else be able
to
provide confirm that I'm making sense in the following
Test::Harness/Test::More style example:
I had to do something similar just yesterday. I wrote a small testlib.pm
that does some setup with import() and some teardown in an END-block
In the test scripts I say:
use lib qw(t);
use testlib qw(things to setup);
in testlib.pm, the custom written import method sets up stuff according
to the (slightly misused) import-list (eg qw(things to setup)). And the
END-block just tears down everything (after checking it's there...)
I guess with some more fiddling the END-block could be made smart enough
to only tear down stuff that was actually set up, but it worked for
me...
--
#!/usr/bin/perl http://domm.zsi.at
for(ref bless{},just'another'perl'hacker){s-:+-$-gprint$_.$/}
