[11.x] Unify exception renderer

[seriquynh]

Nuno's changed the default exception renderer since #51261. Now, there are two ways to customize how Laravel renders an exception.

// Bind/rebind the \Illuminate\Contracts\Foundation\ExceptionRenderer interface.
$this->app->singleton(Illuminate\Contracts\Foundation\ExceptionRenderer::class, function () {
    return new SomeExceptionRendererImpl;
});

// Or bind/rebind the \Illuminate\Foundation\Exceptions\Renderer class.
// It doesn't implement the ExceptionRenderer interface.
$this->app->singleton(Illuminate\Foundation\Exceptions\Renderer\Renderer::class, function () {
    return new SomeRendererSubClass;
});

I think it's complex, inconsistent and introduces more additional checks when actual displaying exceptions because both of them refer to the same thing/category. They defines how an exception should be rendered, right?

Therefore, we can create LaravelRenderer class which implements the ExceptionRenderer interface to unify the concept of rendering exceptions.

Then, inside FoundationServiceProvider, we'll bind the ExceptionRenderer interface to an instance of LaravelRenderer class by default. People can rebind it later.

use Illuminate\Foundation\Exceptions\Renderer\Renderer;

$this->app->singleton(ExceptionRenderer::class, function ($app) {
    return new LaravelRenderer(
        $app[Renderer::class], $app['request']
    );
});

// It's really clear, isn't it?
$this->app->singleton(ExceptionRenderer::class, IgnitionExceptionRenderer::class);
$this->app->singleton(ExceptionRenderer::class, WhoopsExceptionRenderer::class);
$this->app->singleton(ExceptionRenderer::class, AnotherCustomExceptionRenderer::class);

The renderExceptionContent method looks simple as it did before.

protected function renderExceptionContent(Throwable $e)
{
    try {
        if (config('app.debug') && app()->has(ExceptionRenderer::class)) {
            return $this->renderExceptionWithCustomRenderer($e);
        }

        return $this->renderExceptionWithSymfony($e, config('app.debug'));
    } catch (Throwable $e) {
        return $this->renderExceptionWithSymfony($e, config('app.debug'));
    }
}

[seriquynh]

This method just registers macro methods for the Request class. Validation exceptions are only thrown when $request->validate() or $request->validateWithBag() are called and failed.

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If applicable, please consider releasing your code as a package so that the community can still take advantage of your contributions!