CODEWITHSUNDEEP
phpunit-testingphpunit
helllomatt
helllomatt

Reputation: 1339

Testing methods that don't return anything

I'm trying to wrap my head around testing, and I know it's easier than I think. My guess is that I'm going to inevitably have trouble because I wrote the code first and am just now doing tests, instead of having a test driven development process.

My question is about functions that do something like including files. They don't return anything, but they do something for the script as a whole.

Let's say I have a class that includes a file:

<?php 

class Includer {
    public function __construct() {
        $this->include_file("/var/www/index.html");
    }

    public function check_file_validity($file = "") {
        // Check to see if the file exists
        return true; // if exists
    }

    public function include_file($file = "") {
        if ($this->check_file_validity($file)) {
            include $file;
        }        
    }
}

I can write a test to assert that the file exists (check_file_validity), and that would be straight forward.

However, would it be acceptable to return a boolean on the include_file function based on whether or not the file was included? Wouldn't that be a redundant test since basically the same thing is happening when running the check_file_validity function?

I should note that the information given to include the file is coming from the URL, so no files here would be hard coded outside of the tests (unless I mock the $_GET parameters).

Upvotes: 2

Views: 214

Answers (1)

Kuba Birecki
Kuba Birecki

Reputation: 3016

Generally, I think it's safe to assume PHP functions work, and there's no need to test them again. Instead, if you want to test the code that uses a function like include, it might be a good idea to wrap around it. So the code could look like this:

<?php 

class Includer {
    public function __construct() {
        $this->include_file("/var/www/index.html");
    }

    public function check_file_validity($file = "") {
        // Check to see if the file exists
        return true; // if exists
    }

    public function include_file_if_exists($file = "") {
        if ($this->check_file_validity($file)) {
            $this->include_file($file);
        }        
    }

    public function include_file($file = "") {
        include $file;
    }
}

To test include_file_if_exists(), you'd simply mock your class, so you can check whether include_file() was called or not, and if it got the correct argument.

As for include_file() itself, it's not necessary to test it anymore, as it only wraps include.

Upvotes: 1

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