Can I "Mock" time in PHPUnit?

... not knowing if 'mock' is the right word.

Anyway, I have an inherited code-base that I'm trying to write some tests for that are time-based. Trying not to be too vague, the code is related to looking at the history of an item and determining if that item has now based a time threshold.

At some point I also need to test adding something to that history and checking that the threshold is now changed (and, obviously, correct).

The problem that I'm hitting is that part of the code I'm testing is using calls to time() and so I'm finding it really hard to know exactly what the threshold time should be, based on the fact that I'm not quite sure exactly when that time() function is going to be called.

So my question is basically this: is there some way for me to 'override' the time() call, or somehow 'mock out' the time, such that my tests are working in a 'known time'?

Or do I just have to accept the fact that I'm going to have to do something in the code that I'm testing, to somehow allow me to force it to use a particular time if need be?

Either way, are there any 'common practices' for developing time-sensitive functionality that is test friendly?

Edit: Part of my problem, too, is the fact that the time that things occurred in history affect the threshold. Here's an example of part of my problem...

Imagine you have a banana and you're trying to work out when it needs to be eaten by. Let's say that it will expire within 3 days, unless it was sprayed with some chemical, in which case we add 4 days to the expiry, from the time the spray was applied. Then, we can add another 3 months to it by freezing it, but if it's been frozen then we only have 1 day to use it after it thaws.

All of these rules are dictated by historical timings. I agree that I could use the Dominik's suggestion of testing within a few seconds, but what of my historical data? Should I just 'create' that on the fly?

As you may or may not be able to tell, I'm still trying to get a hang of all of this 'testing' concept ;)

I recently came up with another solution that is great if you are using PHP 5.3 namespaces. You can implement a new time() function inside your current namespace and create a shared resource where you set the return value in your tests. Then any unqualified call to time() will use your new function.

For further reading I described it in detail in my https://www.schmengler-se.de/en/2011/03/php-mocking-built-in-functions-like-time-in-unit-tests/">blog</a>

For those of you working with symfony (>= 2.8): Symfony's PHPUnit Bridge includes a ClockMock feature that overrides the built-in methods time, microtime, sleep and usleep.

See: http://symfony.com/doc/2.8/components/phpunit_bridge.html#clock-mocking

You can mock time for test using Clock from ouzo-goodies. (Disclaimer: I wrote this library.)

In code use simply:

$time = Clock::now();

Then in tests:

Clock::freeze('2014-01-07 12:34');
$result = Class::getCurrDate();
$this->assertEquals('2014-01-07', $result);

Carbon::setTestNow(Carbon $time = null) makes any call to Carbon::now() or new Carbon('now') return the same time.

https://medium.com/@stefanledin/mock-date-and-time-with-carbon-8a9f72cb843d

Example:

    public function testSomething()
    {
        $now = Carbon::now();
        // Mock Carbon::now() / new Carbon('now') to always return the same time
        Carbon::setTestNow($now);

        // Do the time sensitive test:
        $this->retroEncabulator('prefabulate')
            ->assertJsonFragment(['whenDidThisHappen' => $now->timestamp])

        // Release the Carbon::now() mock
        Carbon::setTestNow();
    }

The $this->retroEncabulator() function needs to use Carbon::now() or new Carbon('now') internally of course.

I had to simulate a particular request in future and past date in the app itself (not in Unit Tests). Hence all calls to \DateTime::now() should return the date that was previously set throughout the app.

I decided to go with this library https://github.com/rezzza/TimeTraveler, since I can mock the dates without altering all the codes.

\Rezzza\TimeTraveler::enable();
\Rezzza\TimeTraveler::moveTo('2011-06-10 11:00:00');

var_dump(new \DateTime());           // 2011-06-10 11:00:00
var_dump(new \DateTime('+2 hours')); // 2011-06-10 13:00:00

Personally, I keep using time() in the tested functions/methods. In your test code, just make sure to not test for equality with time(), but simply for a time difference of less than 1 or 2 (depending on how much time the function takes to execute)

You can overide php's time() function using the runkit extension. Make sure you set runkit.internal_overide to On

Using [runkit][1] extension:

define('MOCK_DATE', '2014-01-08');
define('MOCK_TIME', '17:30:00');
define('MOCK_DATETIME', MOCK_DATE.' '.MOCK_TIME);

private function mockDate()
{
    runkit_function_rename('date', 'date_real');
    runkit_function_add('date','$format="Y-m-d H:i:s", $timestamp=NULL', '$ts = $timestamp ? $timestamp : strtotime(MOCK_DATETIME); return date_real($format, $ts);');
}


private function unmockDate()
{
    runkit_function_remove('date');
    runkit_function_rename('date_real', 'date');
}

You can even test the mock like this:

public function testMockDate()
{
    $this->mockDate();
    $this->assertEquals(MOCK_DATE, date('Y-m-d'));
    $this->assertEquals(MOCK_TIME, date('H:i:s'));
    $this->assertEquals(MOCK_DATETIME, date());
    $this->unmockDate();
}

In most cases this will do. It has some advantages:

• you don't have to mock anything
• you don't need external plugins
• you can use any time function, not only time() but DateTime objects as well
• you don't need to use namespaces.

It's using phpunit, but you can addapt it to any other testing framework, you just need function that works like assertContains() from phpunit.

1. Add below function to your test class or bootstrap. Default tolerance for time is 2 secs. You can change it by passing 3rd argument to assertTimeEquals or modify function args.

   private function assertTimeEquals($testedTime, $shouldBeTime, $timeTolerance = 2) { $toleranceRange = range($shouldBeTime, $shouldBeTime+$timeTolerance); return $this->assertContains($testedTime, $toleranceRange); }

2. Testing example:

   public function testGetLastLogDateInSecondsAgo() { // given $date = new DateTime(); $date->modify('-189 seconds');

    // when
    $this->setLastLogDate($date);
    
    // then
    $this->assertTimeEquals(189, $this->userData->getLastLogDateInSecondsAgo());
   

   }

assertTimeEquals() will check if array of (189, 190, 191) contains 189.

This test should be passed for correct working function IF executing test function takes less then 2 seconds.

It's not perfect and super-accurate, but it's very simple and in many cases it's enough to test what you want to test.

Simplest solution would be to override PHP time() function and replace it with your own version. However, you cannot replace built-in PHP functions easily (http://no.php.net/manual/en/function.override-function.php">see here).

Short of that, the only way is to abstract time() call to some class/function of your own that would return the time you need for testing.

Alternatively, you could run the test system (operating system) in a virtual machine and change the time of the entire virtual computer.

Here's an addition to fab's post. I did the namespace based override using an eval. This way, I can just run it for tests and not the rest of my code. I run a function similar to:

function timeOverrides($namespaces = array()) {
  $returnTime = time();
  foreach ($namespaces as $namespace) {
    eval("namespace $namespace; function time() { return $returnTime; }");
  }
}

then pass in timeOverrides(array(...)) in the test setup so that my tests only have to keep track of what namespaces time() is called in.

> Disclaimer: I wrote this library.

If you are free to install php extensions in your system, you could then use https://github.com/slope-it/clock-mock.

That library requires ext-uopz >= 6.1.1 and by using ClockMock::freeze and ClockMock::reset you can move the internal php clock to whatever date and time you like. The cool thing about it is that it requires zero modifications to your production code because it mocks transparently \DateTime and \DateTimeImmutable objects as well as some of the global functions (e.g. date(), time(), etc...).