mouragilvan / deprecations

Thin library around different deprecation strategies

Doctrine Deprecations

A small (side-effect free by default) layer on top of trigger_error(E_USER_DEPRECATED) or PSR-3 logging.

• no side-effects by default, making it a perfect fit for libraries that don't know how the error handler works they operate under
• options to avoid having to rely on error handlers global state by using PSR-3 logging
• deduplicate deprecation messages to avoid excessive triggering and reduce overhead

We recommend to collect Deprecations using a PSR logger instead of relying on the global error handler.

Usage from consumer perspective:

Enable Doctrine deprecations to be sent to a PSR3 logger:

\Doctrine\Deprecations\Deprecation::enableWithPsrLogger($logger);

Enable Doctrine deprecations to be sent as @trigger_error($message, E_USER_DEPRECATED) messages.

\Doctrine\Deprecations\Deprecation::enableWithTriggerError();

If you only want to enable deprecation tracking, without logging or calling trigger_error then call:

\Doctrine\Deprecations\Deprecation::enableTrackingDeprecations();

Tracking is enabled with all three modes and provides access to all triggered deprecations and their individual count:

$deprecations = \Doctrine\Deprecations\Deprecation::getTriggeredDeprecations();

foreach ($deprecations as $identifier => $count) {
    echo $identifier . " was triggered " . $count . " times\n";
}

Suppressing Specific Deprecations

Disable triggering about specific deprecations:

\Doctrine\Deprecations\Deprecation::ignoreDeprecations("https://link/to/deprecations-description-identifier");

Disable all deprecations from a package

\Doctrine\Deprecations\Deprecation::ignorePackage("doctrine/orm");

Other Operations

When used within PHPUnit or other tools that could collect multiple instances of the same deprecations the deduplication can be disabled:

\Doctrine\Deprecations\Deprecation::withoutDeduplication();

Disable deprecation tracking again:

\Doctrine\Deprecations\Deprecation::disable();

Usage from a library/producer perspective:

When you want to unconditionally trigger a deprecation even when called from the library itself then the trigger method is the way to go:

\Doctrine\Deprecations\Deprecation::trigger(
    "doctrine/orm",
    "https://link/to/deprecations-description",
    "message"
);

If variable arguments are provided at the end, they are used with sprintf on the message.

\Doctrine\Deprecations\Deprecation::trigger(
    "doctrine/orm",
    "https://github.com/doctrine/orm/issue/1234",
    "message %s %d",
    "foo",
    1234
);

When you want to trigger a deprecation only when it is called by a function outside of the current package, but not trigger when the package itself is the cause, then use:

\Doctrine\Deprecations\Deprecation::triggerIfCalledFromOutside(
    "doctrine/orm",
    "https://link/to/deprecations-description",
    "message"
);

Based on the issue link each deprecation message is only triggered once per request.

A limited stacktrace is included in the deprecation message to find the offending location.

Note: A producer/library should never call Deprecation::enableWith methods and leave the decision how to handle deprecations to application and frameworks.

Usage in PHPUnit tests

There is a VerifyDeprecations trait that you can use to make assertions on the occurrence of deprecations within a test.

use Doctrine\Deprecations\PHPUnit\VerifyDeprecations;

class MyTest extends TestCase
{
    use VerifyDeprecations;

    public function testSomethingDeprecation()
    {
        $this->expectDeprecationWithIdentifier('https://github.com/doctrine/orm/issue/1234');

        triggerTheCodeWithDeprecation();
    }

    public function testSomethingDeprecationFixed()
    {
        $this->expectNoDeprecationWithIdentifier('https://github.com/doctrine/orm/issue/1234');

        triggerTheCodeWithoutDeprecation();
    }
}

What is a deprecation identifier?

An identifier for deprecations is just a link to any resource, most often a Github Issue or Pull Request explaining the deprecation and potentially its alternative.