feat(core)!: overhaul exception handling

composer.json

@@ -212,6 +212,7 @@
             "Tempest\\Cryptography\\Tests\\": "packages/cryptography/tests",
             "Tempest\\Database\\Tests\\": "packages/database/tests",
             "Tempest\\DateTime\\Tests\\": "packages/datetime/tests",
+            "Tempest\\Debug\\Tests\\": "packages/debug/tests",
             "Tempest\\EventBus\\Tests\\": "packages/event-bus/tests",
             "Tempest\\Generation\\Tests\\": "packages/generation/tests",
             "Tempest\\HttpClient\\Tests\\": "packages/http-client/tests",
@@ -249,11 +250,14 @@
         "lint:fix": "vendor/bin/mago lint --fix --format-after-fix",
         "style": "composer fmt && composer lint:fix",
         "test": "composer phpunit",
+        "test:stop": "composer phpunit --stop-on-error --stop-on-failure",
         "lint": "vendor/bin/mago lint --potentially-unsafe --minimum-fail-level=note",
         "phpstan": "vendor/bin/phpstan analyse src tests --memory-limit=1G",
         "rector": "vendor/bin/rector process --no-ansi",
         "merge": "php -d\"error_reporting = E_ALL & ~E_DEPRECATED\" vendor/bin/monorepo-builder merge",
         "intl:plural": "./packages/intl/bin/plural-rules.php",
+        "exceptions:dev": "cd ./packages/router/src/Exceptions/local && bun i && bun run dev",
+        "exceptions:build": "cd ./packages/router/src/Exceptions/local && bun i && bun run build",
         "release": [
             "composer qa",
             "./bin/release"
@@ -267,7 +271,8 @@
             "./bin/validate-packages",
             "./tempest discovery:clear --no-interaction",
             "composer phpunit",
-            "composer phpstan"
+            "composer phpstan",
+            "composer exceptions:build"
         ]
     }
 }

docs/1-essentials/01-routing.md

@@ -299,7 +299,7 @@ final class PasswordlessAuthenticationController
     public function __invoke(Request $request): Response
     {
         if (! $this->uri->hasValidSignature($request)) {
-            return new Invalid();
+            throw new HttpRequestFailed(Status::UNPROCESSABLE_CONTENT);
         }
 
         // …
@@ -704,7 +704,6 @@ Tempest provides several response classes for common use cases, all implementing
 - {b`Tempest\Http\Responses\Back`} — redirects to previous page, accepts a fallback.
 - {b`Tempest\Http\Responses\Download`} — downloads a file from the browser.
 - {b`Tempest\Http\Responses\File`} — shows a file in the browser.
-- {b`Tempest\Http\Responses\Invalid`} — a response with form validation errors, redirecting to the previous page.
 - {b`Tempest\Http\Responses\NotFound`} — the 404 response. Accepts an optional body.
 - {b`Tempest\Http\Responses\ServerError`} — a 500 server error response.
 

docs/2-features/14-exception-handling.md

@@ -1,66 +1,58 @@
 ---
 title: Exception handling
-description: "Learn how to gracefully handle exceptions in your application by writing exception processors."
+description: "Learn how exception handling works, how to manually report exceptions, and how to customize exception rendering for HTTP responses."
 ---
 
 ## Overview
 
-Tempest comes with its own exception handler, which provides a simple way to catch and process exceptions. During local development, Tempest uses [Whoops](https://github.com/filp/whoops) to display detailed error pages. In production, it will show a generic error page.
+Tempest comes with an exception handler that provides a simple way to report exceptions and render error responses.
 
-When an exception is thrown, it will be caught and piped through the registered exception processors. By default, the only registered exception processor, {b`Tempest\Core\LogExceptionProcessor`}, will simply log the exception.
+Custom [exception reporters](#writing-exception-reporters) can be created by implementing the {b`Tempest\Core\Exceptions\ExceptionReporter`} interface, and custom [exception renderers](#customizing-exception-rendering) can be created by implementing {b`Tempest\Router\Exceptions\ExceptionRenderer`}. These classes are automatically [discovered](../1-essentials/05-discovery.md) and do not require manual registration.
 
-Of course, you may create your own exception processors. This is done by creating a class that implements the {`Tempest\Core\ExceptionProcessor`} interface. Classes implementing this interface are automatically [discovered](../1-essentials/05-discovery.md), so you don't need to register them manually.
+## Processing exceptions
 
-## Reporting exceptions
+Exceptions can be reported without throwing them using the `process()` method of the {b`Tempest\Core\Exceptions\ExceptionProcessor`} interface. This allows putting exceptions through the reporting process without stopping the application's execution.
 
-Sometimes, you may want to report an exception without necessarily throwing it. For example, you may want to log an exception, but not stop the execution of the application. To do this, you can use the `Tempest\report()` function.
+```php app/CreateUser.php
+use Tempest\Core\Exceptions\ExceptionProcessor;
 
-```php
-use function Tempest\report;
-
-try {
-    // Some code that may throw an exception
-} catch (SomethingFailed $e) {
-    report($e);
-}
-```
-
-## Disabling default logging
-
-Exception processors are discovered when Tempest boots, then stored in the `exceptionProcessors` property of {`Tempest\Core\AppConfig`}. The default logging processor, {b`Tempest\Core\LogExceptionProcessor`}, is automatically added to the list of processors.
-
-To disable exception logging, you may remove it in a `KernelEvent::BOOTED` event handler:
-
-```php
-use Tempest\Core\AppConfig;
-use Tempest\Core\KernelEvent;
-use Tempest\Core\LogExceptionProcessor;
-use Tempest\EventBus\EventHandler;
-use Tempest\Support\Arr;
-
-final readonly class DisableExceptionLogging
+final readonly class CreateUser
 {
     public function __construct(
-        private AppConfig $appConfig,
-    ) {
-    }
+        private ExceptionProcessor $exceptions
+    ) {}
 
-    #[EventHandler(KernelEvent::BOOTED)]
     public function __invoke(): void
     {
-        Arr\forget_values($this->appConfig->exceptionProcessors, LogExceptionProcessor::class);
+        try {
+            // Some code that may throw an exception
+        } catch (SomethingFailed $somethingFailed) {
+            $this->exceptions->process($somethingFailed);
+        }
     }
 }
 ```
 
+## Disabling exception logging
+
+The default logging reporter, {b`Tempest\Core\Exceptions\LoggingExceptionReporter`}, is automatically added to the list of reporters. To disable it, create a {b`Tempest\Core\Exceptions\ExceptionsConfig`} [configuration file](../1-essentials/06-configuration.md#configuration-files) and set `logging` to `false`:
+
+```php app/exceptions.config.php
+use Tempest\Core\Exceptions\ExceptionsConfig;
+
+return new ExceptionsConfig(
+    logging: false,
+);
+```
+
 ## Adding context to exceptions
 
-Sometimes, an exception may have information that you would like to be logged. By implementing the {`Tempest\Core\HasContext`} interface on an exception class, you can provide additional context that will be logged—and available to other processors.
+Exceptions can provide additional information for logging by implementing the {`Tempest\Core\ProvidesContext`} interface. The context data becomes available to exception processors.
 
 ```php
-use Tempest\Core\HasContext;
+use Tempest\Core\ProvidesContext;
 
-final readonly class UserWasNotFound extends Exception implements HasContext
+final readonly class UserWasNotFound extends Exception implements ProvidesContext
 {
     public function __construct(private string $userId)
     {
@@ -76,47 +68,153 @@ final readonly class UserWasNotFound extends Exception implements HasContext
 }
 ```
 
-## Customizing the error page
+## Writing exception reporters
 
-In production, when an uncaught exception occurs, Tempest displays a minimalistic, generic error page. You may customize this behavior by adding a middleware dedicated to catching {b`Tempest\Http\HttpRequestFailed`} exceptions.
+Exception reporters allow defining custom reporting logic for exceptions, such as sending them to external error tracking services like Sentry or logging them to specific destinations.
 
-For instance, you may display a branded error page by providing a view:
+To create a custom reporter, implement the {b`Tempest\Core\Exceptions\ExceptionReporter`} interface and define a `report()` method:
 
-```php
+```php app/SentryExceptionReporter.php
+use Tempest\Core\Exceptions\ExceptionReporter;
+use Throwable;
+
+final class SentryExceptionReporter implements ExceptionReporter
+{
+    public function __construct(
+        private SentryClient $sentry,
+    ) {}
+
+    public function report(Throwable $throwable): void
+    {
+        $this->sentry->captureException($throwable);
+    }
+}
+```
+
+Exception reporters are automatically [discovered](../4-internals/02-discovery.md) and registered. All registered reporters are invoked whenever an exception is processed, allowing multiple reporters to handle the same exception.
+
+For example, the default logging reporter logs to a file, while the reporter above sends the error to Sentry.
+
+If an exception reporter throws an exception during execution, it is silently caught to prevent infinite loops. This ensures that a failing reporter doesn't prevent other reporters from running.
+
+### Accessing exception context
+
+Exceptions can implement the {b`Tempest\Core\ProvidesContext`} interface, which reporters can leverage to provide additional context data during reporting:
+
+```php app/SentryExceptionReporter.php
+use Tempest\Core\Exceptions\ExceptionReporter;
+use Tempest\Core\ProvidesContext;
+use Sentry\State\HubInterface as Sentry;
+use Sentry\State\Scope;
+
+final class SentryExceptionReporter implements ExceptionReporter
+{
+    public function __construct(
+        private readonly Sentry $sentry,
+    ) {}
+
+    public function report(Throwable $throwable): void
+    {
+        $this->sentry->withScope(function (Scope $scope) use ($throwable) {
+            if ($throwable instanceof ProvidesContext) {
+                $scope->withContext($throwable->context());
+            }
+
+            $scope->captureException($throwable);
+        });
+    }
+}
+```
+
+### Conditional reporting
+
+Reporters can implement conditional logic to only report specific exception types or under certain conditions. There is no built-in filtering mechanism; reporters are responsible for determining when to report an exception.
+
+```php app/CriticalErrorReporter.php
+use Tempest\Core\Exceptions\ExceptionReporter;
+use Throwable;
+
+final class CriticalErrorReporter implements ExceptionReporter
+{
+    public function __construct(
+        private AlertService $alerts,
+    ) {}
+
+    public function report(Throwable $throwable): void
+    {
+        if (! $throwable instanceof CriticalException) {
+            return;
+        }
+
+        $this->alerts->sendCriticalAlert(
+            message: $throwable->getMessage(),
+        );
+    }
+}
+```
+
+## Customizing exception rendering
+
+Exception renderers provide control over how exceptions are rendered in HTTP responses. Custom renderers can be used to display specialized error pages for specific exception types, format errors differently based on content type (JSON, HTML, XML), or provide user-friendly error messages for common scenarios like 404 or validation failures.
+
+To create a custom renderer, implement the {b`Tempest\Router\Exceptions\ExceptionRenderer`} interface. It requires a `canRender()` method to determine if the renderer can handle the given exception and request, and a `render()` method to produce the response:
+
+```php app/NotFoundExceptionRenderer.php
+use Tempest\Http\ContentType;
 use Tempest\Http\HttpRequestFailed;
-use Tempest\Router\HttpMiddleware;
+use Tempest\Http\Request;
+use Tempest\Http\Response;
+use Tempest\Http\Responses\NotFound;
+use Tempest\Http\Status;
+use Tempest\Router\Exceptions\ExceptionRenderer;
+use Throwable;
+
 use function Tempest\view;
 
-final class CatchHttpRequestFailuresMiddleware implements HttpMiddleware
+final class NotFoundExceptionRenderer implements ExceptionRenderer
 {
-    public function __invoke(Request $request, HttpMiddlewareCallable $next): Response
+    public function canRender(Throwable $throwable, Request $request): bool
     {
-        try {
-            return $next($request);
-        } catch (HttpRequestFailed $failure) {
-            return new GenericResponse(
-                status: $failure->status,
-                body: view('./error.view.php', failure: $failure),
-            );
+        if (! $request->accepts(ContentType::HTML)) {
+            return false;
         }
+
+        if (! $throwable instanceof HttpRequestFailed) {
+            return false;
+        }
+
+        return $throwable->status === Status::NOT_FOUND;
+    }
+
+    public function render(Throwable $throwable): Response
+    {
+        return new NotFound(
+            body: view('./404.view.php'),
+        );
     }
 }
 ```
 
+:::info
+Exception renderers are automatically [discovered](../4-internals/02-discovery.md) and checked in {b`#[Tempest\Core\Priority]`} order.
+:::
+
 ## Testing
 
-By extending {`Tempest\Framework\Testing\IntegrationTest`} from your test case, you gain access to the exception testing utilities, which allow you to make assertions about reported exceptions.
+By extending {`Tempest\Framework\Testing\IntegrationTest`} from a test case, exception testing utilities may be accessed for making assertions about processed exceptions.
 
 ```php
-// Prevents exceptions from being actually processed
-$this->exceptions->preventReporting();
+// Allows exceptions to be processed during tests
+$this->exceptions->allowProcessing();
 
-// Asserts that the exception was reported
-$this->exceptions->assertReported(UserNotFound::class);
+// Assert that the exception was processed
+$this->exceptions->assertProcessed(UserNotFound::class);
 
-// Asserts that the exception was not reported
-$this->exceptions->assertNotReported(UserNotFound::class);
+// Assert that the exception was not processed
+$this->exceptions->assertNotProcessed(UserNotFound::class);
 
-// Asserts that no exceptions were reported
-$this->exceptions->assertNothingReported();
+// Assert that no exceptions were processed
+$this->exceptions->assertNothingProcessed();
 ```
+
+By default, Tempest disables exception processing during tests. It is recommended to unit-test your own {b`Tempest\Core\Exceptions\ExceptionReporter`} implementations.

packages/console/src/Exceptions/ConsoleExceptionHandler.php

@@ -9,11 +9,9 @@
 use Tempest\Console\GlobalFlags;
 use Tempest\Console\HasExitCode;
 use Tempest\Console\Input\ConsoleArgumentBag;
-use Tempest\Container\Container;
 use Tempest\Container\Tag;
-use Tempest\Core\AppConfig;
 use Tempest\Core\ExceptionHandler;
-use Tempest\Core\ExceptionReporter;
+use Tempest\Core\Exceptions\ExceptionProcessor;
 use Tempest\Core\Kernel;
 use Tempest\Highlight\Escape;
 use Tempest\Highlight\Highlighter;
@@ -25,20 +23,18 @@
 final readonly class ConsoleExceptionHandler implements ExceptionHandler
 {
     public function __construct(
-        private AppConfig $appConfig,
-        private Container $container,
         private Kernel $kernel,
         #[Tag('console')]
         private Highlighter $highlighter,
         private Console $console,
         private ConsoleArgumentBag $argumentBag,
-        private ExceptionReporter $exceptionReporter,
+        private ExceptionProcessor $exceptionProcessor,
     ) {}
 
     public function handle(Throwable $throwable): void
     {
         try {
-            $this->exceptionReporter->report($throwable);
+            $this->exceptionProcessor->process($throwable);
 
             $this->console
                 ->writeln()

packages/core/src/AppConfig.php

@@ -15,9 +15,6 @@ public function __construct(
 
         ?string $baseUri = null,
 
-        /** @var class-string<\Tempest\Core\ExceptionProcessor>[] */
-        public array $exceptionProcessors = [],
-
         /**
          * @var array<class-string<\Tempest\Core\InsightsProvider>>
          */