This weekend I released two versions of
Net::AMQP::RabbitMQ on CPAN: 0.007000 and 0.007001.
The first version was the culmination of some major refactoring in how Perl types were inferred into C and AMQP types in headers, and then also adding a bunch of previously-unsupported AMQP header types into Perl.
The second version was fixing an oversight where
timestamp types in headers weren’t supported. I also added a
manual_tests directory which is where I will add some manual tests as I do some of those. There is a test where I verify dead-letter queue functionality that helped me verify that
x-death headers were working properly now.
The primary reason why this is huge is because the special
x-death headers are now supported. Not only that, but in the event that you had a non-Perl program publishing to your queue with headers, you may have had compatibility issues with the header types that would cause to have to kluge.
As of now, the new version – 0.007001 – isn’t live, but if you search for the module on CPAN you should find the latest published version.
If you notice any issues, let me know by going to the official github repo and filing an issue.
Today I got tests done, and I kinda abandoned
Error.pm for exception handling. I switched over to using
Try::Tiny since it looks like there are known issues with Error.pm in more modern frameworks like
Moose. I’m going to try to avoid using ##no critic as much as I can, but I had to use it twice in my
ModExec::Exception class since I wanted to include the sugar functions from
Try::Tiny, and since I want to use
die() in my throws to keep the object intact.
Here’s tonight’s changeset: http://tinyurl.com/nuzvnzt
Next up is the base class,
In re-factoring ModExec, I have started with the exceptions. I’m debating how I used to do them. When I first started I used
Error qw/:try/ and
Error::Simple for exceptions. I still think I will, it looks like it’s still being well-maintained by Shlomi Fish (see here).
I think that the piece I will bite off first is to get some test coverage around my exceptions and add documentation. They’re not much more than what you get with
Error::Simple, but there’s some stuff in there for stack dumps and things like that.
Goals for this first pass are:
- Pass a
`perlcritic -3` for all exception code
- Add POD for all exception code
- Add a test for at least some of the methods (more tests will be added later)
Before and After
Here are some GitHub links:
One of the largest critiques I see about regular expressions is that they lack readability. Well, in Perl 5.10 named capture was added (http://perldoc.perl.org/perlretut.html) which I think adds an awful lot of readability to Perl regular expressions. Continue reading “Gist of the Day: Named Capture in Perl Regular Expressions (Briefly)”
Parallel processing is all the rage these days, and life has me at a point where I’m needing to use it. I am having to minimize dependencies in the task at hand, so I’m having to forego my usual CPAN modules and use basic system calls. It’s not terribly complicated, but just to refresh myself on the basics I went ahead and whipped up a quick demo that I thought others might find useful. This is a very simple demonstration of how to use
wait(). Continue reading “Gist of the Day: Playing with Forks”
I like repeatable tests. The #1 benefit of repeatable tests is that they’re repeatable. This also means they’re less vulnerable to data changes (e.g. this test depends on this product record remaining unchanged) and don’t pollute your environment. There are two ways that I think you can make your tests repeatable, and I think both of them are equally valid, and each should be used in their appropriate time:
- Creating and tearing down fixtures
- Using some sort of mocking framework to force a repeatable result from an up-stream dependency that is not what you’re trying to test
Continue reading “Gist of the Day: Test::MockModule for Repeatable Tests!”
Hey all, I just wanted to let you know that I didn’t die… I am only going through a job change and a move, so I am currently bogged down with a number of things.
I expect to be back up and running again by next weekend at the latest. I suspect very few people care, but in the event that you do, now you know.
I’ll share all of the details when I have them 🙂
First, I suppose I should apologize for two days of silence. I am currently going through a major life transition, so things could get a little spotty for a while. I haven’t forgotten about you. I actually have had a couple of days where my experiment for the Gist of the Day failed, and I couldn’t get something working in time to put it up.
Today, however, I do have something for you!
Today we are going to cover two topics very briefly (as usual): 1) how do you factor files you wrote into your tests, and 2) how do you write your code with testing in mind (which you should). Continue reading “Gist of the Day: How to Test a File You Wrote!”
In programming you will commonly see abstraction layers. Say, for instance, you wanted to have a program to take some arbitrary data format and load it into your data. We’ll call it product feeds (just because some people like relevant examples). So, you want to pull in product data from various different web sites and vendors to list some products on your site. Now if you have ever done this task before then you’re already thinking “jeez, what a pain in the ass it is to get everybody to use the same format!” If you’ve done this task before then you’ve probably already dabbled in this type of abstraction. In Perl – my go-to language (since I arbitrarily prefer it) – this usually results in dynamically loading a “driver” class based on the data format which is likely vendor-specific. This makes it easy/easier for you to allow each data source to have its own format while using them all in the same way.
If you were to pick a Design Pattern for this, you would do well to choose a Factory pattern. In Perl, since you have so much dynamic leeway, you don’t need to go with a pure Factory pattern here, but what you end up with I think is most certainly in keeping with a factory pattern.
For this Gist, I will demonstrate three common ways to get from knowing which class you need to getting that class:
Continue reading “Gist of the Day: There's More Than One Way to Switch Your Class!”