Testing ID Generation

Html::generateId() produces IDs that include an hrtime(true) timestamp, making them unique across requests but non-deterministic in tests. The file src/test-functions.php provides helpers that make generated IDs predictable during testing.

Setup

Include the file once before running tests:

require_once 'vendor/yiisoft/html/src/test-functions.php';

Functions

\Yiisoft\Html\IdGenerator\disableSeed()

Disables the hrtime() seed: IDs become short and deterministic — i1, i2, test1, etc. Call this in test setup to get predictable, hardcodable IDs.

\Yiisoft\Html\IdGenerator\enableSeed()

Re-enables the hrtime() seed, reverting to the default behaviour where IDs include a timestamp. Call this in test teardown to restore normal operation.

\Yiisoft\Html\IdGenerator\reset()

Resets the counter to zero without changing the current seed mode. Useful when you need a fresh counter mid-test while the seed is disabled.

Usage in PHPUnit

Bootstrap

To load the file automatically for the entire test suite, add it to your bootstrap file.

In phpunit.xml:

<phpunit bootstrap="tests/bootstrap.php">

In tests/bootstrap.php:

// ...
require_once 'vendor/autoload.php';
require_once 'vendor/yiisoft/html/src/test-functions.php';
// ...

Global disableSeed with per-test reset

If all tests in the suite need deterministic IDs, call disableSeed() once in the bootstrap and then call reset() at the start of each test that relies on specific ID values:

In tests/bootstrap.php:

require_once 'vendor/yiisoft/html/src/test-functions.php';

\Yiisoft\Html\IdGenerator\disableSeed();

In the test class:

use Yiisoft\Html\IdGenerator;

final class MyTest extends TestCase
{
    public function testRendersLabel(): void
    {
        IdGenerator\reset();

        $this->assertSame('<label for="i1">Name</label>', ...);
    }
}

setUp() and tearDown()

Useful when only one test class (or a few) needs deterministic IDs while the rest of the suite uses the default hrtime() behaviour — for example, when adding ID assertions to an existing project without touching the global bootstrap.

Call disableSeed() and reset() in setUp() so every test starts with deterministic IDs from i1. Add enableSeed() in tearDown() to restore the default behaviour after the class finishes:

use Yiisoft\Html\IdGenerator;

final class MyTest extends TestCase
{
    protected function setUp(): void
    {
        IdGenerator\disableSeed();
        IdGenerator\reset();
    }

    protected function tearDown(): void
    {
        IdGenerator\enableSeed();
    }

    public function testRendersLabel(): void
    {
        // IDs are now i1, i2, … — safe to hardcode in assertions
        $this->assertSame('<label for="i1">Name</label>', ...);
    }
}