README

A PSR-11 compliant dependency injection container for PHP 8.2+. Supports autowiring, contextual bindings, tagged services, lazy proxies, scoped lifetimes, method injection, decorators, and built-in testing and profiling utilities.

Requirements

PHP ^8.2

Installation

composer require denosyscore/container

Quick Start

use Denosys\Container\Container;

$container = new Container();

// Bind an interface to a concrete class
$container->bind(LoggerInterface::class, FileLogger::class);

// Bind as a singleton
$container->singleton(CacheInterface::class, RedisCache::class);

// Resolve — dependencies are injected automatically
$logger = $container->get(LoggerInterface::class);
$cache  = $container->get(CacheInterface::class);

assert($cache === $container->get(CacheInterface::class)); // same instance

Autowiring

The container inspects constructor type-hints and resolves dependencies automatically. No explicit registration is needed for concrete classes:

class OrderService
{
    public function __construct(
        private readonly PaymentGateway $payment,
        private readonly InventoryRepository $inventory,
    ) {}
}

// PaymentGateway and InventoryRepository are built and injected automatically
$service = $container->get(OrderService::class);

Union-typed parameters are tried in order. Nullable and defaulted parameters fall back gracefully without throwing.

Explicit Bindings

bind()

// Interface to concrete class
$container->bind(LoggerInterface::class, FileLogger::class);

// Factory closure
$container->bind(DatabaseConnection::class, function (Container $c) {
    return new DatabaseConnection(config('db.dsn'));
});

singleton()

Resolved once; the same instance is returned on every subsequent call:

$container->singleton(CacheManager::class, RedisCacheManager::class);

$a = $container->get(CacheManager::class);
$b = $container->get(CacheManager::class);

assert($a === $b); // true

instance()

$container->instance(Config::class, new Config(['debug' => true]));

alias()

Create a short name for a bound abstract. The abstract must already be bound or be an instantiable class:

$container->bind(PaymentGateway::class, StripeGateway::class);
$container->alias('stripe', PaymentGateway::class);

$gateway = $container->get('stripe');

extend()

Wrap an existing binding or resolved instance with additional behavior:

$container->singleton(MailerInterface::class, SmtpMailer::class);

$container->extend(MailerInterface::class, function (MailerInterface $mailer, Container $c) {
    return new LoggingMailerDecorator($mailer);
});

Contextual Bindings

Inject different implementations of the same interface depending on which class is requesting it:

$container->when(OrderController::class)
    ->needs(LoggerInterface::class)
    ->give(OrderLogger::class);

$container->when(PaymentController::class)
    ->needs(LoggerInterface::class)
    ->give(PaymentLogger::class);

Supply all services tagged with a given tag to a context:

$container->when(ReportBuilder::class)
    ->needs(FormatterInterface::class)
    ->giveTagged('report.formatters');

Tagged Services

Group related bindings under a shared tag and resolve all of them at once:

$container->bind(CsvFormatter::class, CsvFormatter::class);
$container->bind(JsonFormatter::class, JsonFormatter::class);

$container->tag(
    [CsvFormatter::class, JsonFormatter::class],
    'report.formatters'
);

$formatters = $container->tagged('report.formatters');
// Returns resolved instances of all tagged services

$abstracts = $container->resolveAll(FormatterInterface::class);
// Keyed by abstract name

A single abstract can carry multiple tags:

$container->tag(AuditLogger::class, ['loggers', 'auditors']);

Scoped Bindings

Override bindings within a bounded scope. The original bindings are automatically restored when the callable returns:

$result = $container->scoped([
    LoggerInterface::class => TestLogger::class,
], function () use ($container, $order) {
    // OrderService receives TestLogger inside this scope
    return $container->get(OrderService::class)->process($order);
});
// LoggerInterface is back to its original binding here

Lazy Loading

Defer resolution until the first method call. Useful for expensive services that may not be needed on every request path:

$proxy = $container->lazy(ReportGenerator::class);

// ReportGenerator is NOT instantiated yet

$report = $proxy->generate($data);
// Resolved on first call, then reused

The proxy implements Denosys\Container\LazyProxy and transparently forwards all method calls to the underlying instance once triggered.

Method Injection

call()

Invoke any callable with automatic injection of type-hinted parameters:

$result = $container->call(function (MailerInterface $mailer, string $subject = 'Hello') {
    return $mailer->send($subject);
});

// Object method
$result = $container->call([$controller, 'index']);

// Pass extra parameters — these override or supplement resolved ones
$result = $container->call([OrderService::class, 'process'], ['orderId' => 42]);

callStatic()

Call a static method with automatic injection:

$result = $container->callStatic(ReportGenerator::class, 'buildSummary');

Decorators

decorate()

Wrap a resolved service. Multiple decorators are applied in descending $priority order (higher runs first):

$container->bind(CacheInterface::class, RedisCache::class);

$container->decorate(CacheInterface::class, function (CacheInterface $cache, Container $c) {
    return new MetricsCollectingCache($cache);
}, priority: 10);

$container->decorate(CacheInterface::class, function (CacheInterface $cache, Container $c) {
    return new LoggingCache($cache);
}, priority: 5);

// Chain: RedisCache -> MetricsCollectingCache -> LoggingCache
$cache = $container->get(CacheInterface::class);

middleware()

Middleware behaves like a decorator without priority ordering. Applied in registration order, after all decorate() layers:

$container->middleware(RepositoryInterface::class, function (RepositoryInterface $repo, Container $c) {
    return new CachingRepository($repo, $c->get(CacheInterface::class));
});

Testing Utilities

mock()

Replace a binding with a test double. Mocks take priority over all other bindings and are never decorated:

$mockMailer = $this->createMock(MailerInterface::class);
$mockMailer->expects($this->once())->method('send');

$container->mock(MailerInterface::class, $mockMailer);

$container->get(OrderService::class)->checkout($order);

spy()

Wrap a real service instance to track its resolution count and timing without replacing it:

$spy = $container->spy(PaymentGateway::class);

// ... exercise code that uses PaymentGateway ...

echo $spy->getResolutionCount();        // number of times resolved
echo $spy->getAverageResolutionTime();  // average ms per resolution
echo $spy->getTotalResolutionTime();    // total ms across all resolutions

$summary = $spy->getSummary();
// ['abstract' => ..., 'resolution_count' => ..., 'average_resolution_time' => ...]

Container Validation

Check for misconfigured or unresolvable bindings without instantiating anything:

$result = $container->validate();

if (!$result->isValid()) {
    foreach ($result->getIssues() as $issue) {
        echo $issue->getDescription();
        // "[error] Cannot resolve 'PaymentGateway' (Abstract: ...) Suggestions: ..."
    }
}

$errors   = $result->getIssuesBySeverity('error');
$warnings = $result->getIssuesBySeverity('warning');

echo $result->getSummary();
// "Validation failed. 2 issues found: 1 errors, 1 warnings."
// or: "Validation passed. No issues found."

ValidationIssue severity levels: error, warning, info.

Performance

getPerformanceMetrics()

Returns a PerformanceReport with timing, cache ratios, and memory stats accumulated since the container was constructed:

$report = $container->getPerformanceMetrics();

echo $report->getSummary();
// Performance Score: 95/100
// Total Resolutions: 342
// Average Resolution Time: 0.42ms
// Cache Hit Ratio: 87.4%
// Peak Memory Usage: 12.30MB

$score  = $report->getPerformanceScore();      // 0-100
$slow   = $report->slowestResolutions;         // array<string, float> abstract => ms
$top    = $report->getMostResolvedServices(5); // top 5 most-resolved services
$issues = $report->getPerformanceIssues();     // array<string> human-readable warnings

getResolutionHistory()

Returns a ring-buffer of recent resolution records (default limit: 1000 entries):

$history = $container->getResolutionHistory();

foreach ($history as $entry) {
    printf(
        "%s resolved in %.2fms (mock: %s)\n",
        $entry['abstract'],
        $entry['resolution_time'],
        $entry['from_mock'] ? 'yes' : 'no'
    );
}
// Keys per entry: abstract, resolution_time, from_mock, timestamp, memory_usage

Lower the ring-buffer size to reduce memory overhead:

$container->setResolutionHistoryLimit(200);

License

MIT

denosyscore / container

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