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Jani Hartikainen:
How many tests is too many?
Sep 13, 2016 @ 09:21:21

While not specific to PHP Jani Hartikainen asks an interesting question in his latest post - how many tests are too many?. He gives an example of the number of tests in a widely used open source project and how, sometimes, more tests doesn't mean better code.

Some time ago I stumbled upon some crazy stuff… Specifically, I found out that SQLite has 787 times more tests than they have actual code! It’s no joke, it’s documented right on their website. While they have about 116 300 lines of source code, they have 91 577 300 lines of test code.

That sounds completely insane. [...] I bet you’ve sometimes wondered what is the right amount of tests to write. In some cases, it’s easy to end up with more tests than code. [...] When thinking of how many tests is enough, we need to think of what the goals are – both for the tests and our actual project.

He focuses in on this last idea, talking more about the SQLite project and its test suite. He then helps answer the main question - how do you know how many tests are enough? Should you "bend over backwards" to make tests for every possible scenario just because you can? He suggests a few things that can help the situation including refactoring where testing is difficult and writing regression tests for bugs fixed.

tagged: testing code opinion toomany unittest sqlite project

Link: http://codeutopia.net/blog/2016/09/10/how-many-tests-is-too-many/

Joe Ferguson:
Solidify Fragile Tests
Sep 05, 2016 @ 11:43:27

In this post to his site Joe Ferguson gives some advice on solidifying tests in your system that are a bit more fragile. Every test suite of any larger size has these kinds of tests - ones that usually pass but sometimes fail (and then pass just fine on the next run).

On my first week at the new job I was tasked to fix some tests that were logging data. While the fix was simple enough, by using `PsrLogNullLogger as Logger` instead of `MonologLogger` in the test, during the process I ran into another test that appeared quite fragile.

He gives an example of a fragile test, one based on a method that returns a "food" value, that would potentially fail if the data returned is not in the right order. He found the issue was with the use of the assertArraySubset check and how, thankfully, the fix was as easy as changing the assertion (and using an array_diff to help with the check).

tagged: solidify fragile tests unittest check assertion update

Link: https://www.joeferguson.me/solidify-fragile-tests/

ShippingDocker.com:
Testing in Docker (Using Different PHP Versions)
Aug 12, 2016 @ 12:23:58

On the ShippingDocker.com site there's a video (and matching tutorial) posted showing you how to use Docker to test with multiple PHP versions with relatively little difficulty. In this case they're not testing the frontend of the application, they're running its unit tests.

[This is a] quick video on running PHP unit tests against different versions of PHP using Docker. [We'll] cover unit testing with PHP.

They start with an example of using the pywatch tool to do the testing without Docker, automatically executing the tests when something changes. This has the limitation of only being able to use your current, local version of PHP. They then shift over to the Docker side of things and show how to run the same pywatch command inside a container of your choosing, tagging it with the PHP version and making it easy to switch between them in the future.

tagged: docker version unittest different example video screencast tutorial

Link: https://shippingdocker.com/blog/docker-testing/

Adam Wathan:
Stubbing Eloquent Relations for Faster Tests
Aug 08, 2016 @ 11:52:53

Adam Wathan has a recent post to his site showing you how to stub out your Eloquent relations in a Laravel application for use in your testing (rather than hitting the database directly).

When you’re trying to test methods on an Eloquent model, you often need to hit the database to really test your code.

But sometimes the functionality you’re testing doesn’t really depend on database features. Is there any way to test that stuff without hitting the database?

He starts with a look at the more traditional method, using the models normally and testing with the database. He includes a simple test and class showing a basic "song duration" integer response. He gets into a bit more detail on how the Eloquent code grabs the data it needs when a relation is accessed (hint: not a separate query) and how to update the test to mimic the eager loading of the duration information. He ends the post by pointing out that "nothing is free" however as, if the underlying database implementation changes, the test would start to fail regardless of it not using the database.

tagged: tutorial screencast example relation eloquent unittest stub

Link: https://adamwathan.me/2016/08/04/stubbing-eloquent-relations-for-faster-tests/

SitePoint PHP Blog:
Hassle-Free Filesystem Operations during Testing? Yes Please!
Jul 28, 2016 @ 12:24:56

On the SitePoint PHP blog there's a new tutorial posted suggesting a method for hassle-free filesystem operations during testing in your applications. Traditionally external sources, including the file system have proved difficult to test mostly because connection/state issues or conflicts.

When working with the filesystem in our tests suites, a big concern is cleaning up the temporary files after each test runs. However, if for any reason the test’s execution is interrupted before the cleanup phase, further tests might fail, as the environment has not been cleaned up.

In this post, we will use a library named vfsStream to create filesystem mocks. It’s little more than a wrapper around a virtual filesystem, which also works very nicely with PHPUnit.

They start by creating a simple FileCreator class that just uses a file_put_contents call to write data to a provided path. They start with the traditional approach in testing - just writing to the actual file and ensuring it exists. Then comes vfsStream, changing up the testing to use mocks of the directory and file and it's own checks to ensure existence. These mocks work in basically the same way as a directory/filesystem structure would without the external interaction making it much easier to test in isolation.

tagged: filesystem testing phpunit unittest vfsstream package tutorial

Link: https://www.sitepoint.com/hassle-free-filesystem-operations-during-testing/

SitePoint PHP Blog:
Testing Your Tests? Who Watches the Watchmen?
Jul 21, 2016 @ 12:10:48

In a tutorial posted to the SitePoint PHP blog Claudio Ribeiro tries to answer the question of "who watches the watchmen" (your application's tests) to ensure they're functioning as expected and are correct. In this new tutorial he introduces the Humbug mutation testing tool and how it can be used to verify your own tests.

Regardless of whether you’re working for a big corporation, a startup, or just for yourself, unit testing is not only helpful, but often indispensable. We use unit tests to test our code, but what happens if our tests are wrong or incomplete? What can we use to test our tests? Who watches the watchmen?

[...] Mutation Testing ( or Mutant Analysis ) is a technique used to create and evaluate the quality of software tests. It consists of modifying the tests in very small ways. Each modified version is called a mutant and tests detect and reject mutants by causing the behavior of the original version to differ from the mutant. Mutations are bugs in our original code and analysis checks if our tests detect those bugs. In a nutshell, if a test still works after it’s mutated, it’s not a good test.

He starts by helping you get it installed (a quick composer require) and creating a simple "calculator" test to show it in use. He then creates the test for the class with some simple testing methods for the basic calculator functionality. He then configures the Humbug installation (via a JSON config file) and executes it on the current tests, sharing the resulting output. He goes through the results showing how to interpret them and points out places where the tests could be improved.

tagged: testing unittest humbug mutation variation example tutorial output

Link: https://www.sitepoint.com/testing-your-tests-who-watches-the-watchmen/

Laravel News:
Easily Test Email with MailThief
Jun 24, 2016 @ 11:50:56

The Laravel News site has a post that gives you a quick introduction to MailThief, a library created by the developers at Tighten Co. to make mail testing simpler.

MailThief is a new package by Tighten Co. that provides a fake mailer for your Laravel application. This makes it easy to test email without actually sending any.

They include a simple example of a script that sends an email on user registration using Laravel's own Mail library. They also include a test for the registration action showing how MailThief can be used to "hijack" the mailer and make it simpler to get information about the mail being sent. You can find out more about the tool and what prompted it in this video from Adam Wathan.

tagged: mailthief testing unittest mailer email example introduction

Link: https://laravel-news.com/2016/06/mailthief/

Richard Bagshaw:
Prophecy
Jun 24, 2016 @ 09:11:01

Richard Bagshaw has a post to his site sharing some of his experience with the Prophecy testing tool and how it compares to Mockery for creating test doubles (mocks and stubs).

For a while now I have been using Mockery as my test double framework of choice, however recently I have been taking a look at Prophecy as an alternative.

[...] "Prophecy is a highly opinionated yet very powerful and flexible PHP object mocking framework. Though initially it was created to fulfil phpspec2 needs, it is flexible enough to be used inside any testing framework out there with minimal effort."

He then gets into some basic usage of the tool - creating a basic mock, assigning expectations and behaviors and performing the test. He steps through each line of the example explaining what's happening and what can be expected as a result. He ends the post with some final thoughts comparing Prophecy to the normal PHPUnit mocking tools and points out several other features it makes easier to work with as well.

tagged: prophecy unittest doubles mock stub example introduction tutorial

Link: http://www.richardbagshaw.co.uk/prophecy/

Paul Jones:
When Possible, Use File *Resources* Instead Of File *Names*
May 13, 2016 @ 10:37:38

In this new post to his site Paul Jones makes a recommendation to those working with files and other resources: pass around the resources themselves (the streams) not filenames.

In testing the Aura.Http package, I have realized that it’s much more flexible, testing wise, to pass around file resources (a.k.a. handles, pointers, or streams) than it is to pass around file names. When you do that, you can use a php://memory stream instead of attempting to touch the file system. [...] This places control of the file creation in your hands directly, not under the control of the system under test.

He gives examples based on some testing of one of his own packages where he needed to swap out the resource being tested and mock out a file system call. It's a simple trick but could help reduce some complexity in your overall code in the right situations.

tagged: file resource name unittest testing aurahttp

Link: http://paul-m-jones.com/archives/2487

Adam Wathan:
Writing Your Own Test Doubles
May 11, 2016 @ 10:19:58

In this recent post to his site Adam Wathan about writing your own custom test doubles (fakes) to help make your tests cleaner and improve their overall readability/maintainability.

Once in a while I run into a situation where trying to use a mocking library hurts the readability of my test. For example, say I’m building out a basic user registration flow where someone signs up and receives a welcome email. [...] To test that an account is created correctly, I can make a request to the endpoint and verify that the new account exists in a test database. [...] This covers creating the account itself, but what’s the best way to test the welcome email?

He goes through a few of the options that could be used to test this including using Mockery to replace the mailer class with a spy or actually sending emails. There's downfalls to both of these methods and he suggests using a custom "fake" where the mailer class is swapped out with an "in-memory" option with the same kind of interface. He does point out a few issues with this method, however, and offers a few tips to remember when using them.

tagged: custom test unittest doubles email example video screencast

Link: http://adamwathan.me/2016/01/25/writing-your-own-test-doubles/