New in Symfony 6.2: Clock Component
Testing time-related functions is difficult and produces transient test errors.
That’s why we introduced Clock mocking for tests in Symfony 2.8, more than
six years ago. In Symfony 6.2 we’re expanding those efforts with the introduction
of a new component called Clock.
This new component will improve the testability of your time-sensitive code. The
PHP-FIG group is working on a similar proposal in PSR-20, so we designed
Symfony Clock component to ease compatibility with it.
First, this component defines the following ClockInterface:
// returns the current datetime (it’s designed to be compatible with PSR-20)
public function now(): DateTimeImmutable;
// advances the clock by the provided number of seconds
public function sleep(float|int $seconds): void;
// changes the time zone returned by now()
public function withTimeZone(DateTimeZone|string $timezone): static;
In addition to the interface, the component provides three concrete implementations:
NativeClock, uses the system clock, so it returns the real current time,
it sleeps the actual number of seconds given, etc.;
MockClock, suited for tests, it always returns the same datetime (the one
passed to its constructor) and it advances time instantly, without calling to
the real sleep() function of PHP;
MonotonicClock, suited for performance profiling, it uses the monotonic
clock provided by PHP via hrtime() function and it sleeps the actual number
of seconds given).
Related to this, in Symfony 6.2 we’ve also improved the existing ClockMock
class of PHPUnit Bridge component. In #47295,
Christian Flothmann added support
for mocking the hrtime() function.