Accept text/plain events from the Plausible tracker

The Plausible tracker posts its JSON payload with Content-Type text/plain,
  which Laravel does not parse, so every real event failed validation and
  was redirected instead of being forwarded.

  - Decode the raw body when the request is not JSON
  - Respond with 400 instead of a redirect on invalid non-JSON requests
  - Trim trailing slash from the configured domain when forwarding events
  - Add a 5s timeout and respond with 502 when Plausible is unreachable

src/Http/Controllers/PlausibleEventApiController.php

@@ -2,18 +2,30 @@
 
 namespace Mattitja\LaravelPlausibleProxy\Http\Controllers;
 
+use Illuminate\Http\Client\ConnectionException;
 use Illuminate\Http\Response;
 use Illuminate\Support\Facades\Http;
+use Illuminate\Support\Facades\Log;
 use Mattitja\LaravelPlausibleProxy\Http\Requests\PlausibleEventRequest;
 
 class PlausibleEventApiController
 {
     public function __invoke(PlausibleEventRequest $request): Response
     {
-        $upstream = Http::withHeaders([
-            'User-Agent' => (string) $request->userAgent(),
-            'X-Forwarded-For' => (string) $request->ip(),
-        ])->post(config('plausible-proxy.domain').'/api/event', $request->all());
+        $url = rtrim((string) config('plausible-proxy.domain'), '/').'/api/event';
+
+        try {
+            $upstream = Http::timeout(5)
+                ->withHeaders([
+                    'User-Agent' => (string) $request->userAgent(),
+                    'X-Forwarded-For' => (string) $request->ip(),
+                ])
+                ->post($url, $request->all());
+        } catch (ConnectionException $e) {
+            Log::error('Failed to forward Plausible event: '.$e->getMessage());
+
+            return response('Bad Gateway', 502);
+        }
 
         return response($upstream->body(), $upstream->status())
             ->header('Content-Type', $upstream->header('Content-Type') ?: 'text/plain');

src/Http/Requests/PlausibleEventRequest.php

@@ -2,7 +2,9 @@
 
 namespace Mattitja\LaravelPlausibleProxy\Http\Requests;
 
+use Illuminate\Contracts\Validation\Validator;
 use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Http\Exceptions\HttpResponseException;
 
 class PlausibleEventRequest extends FormRequest
 {
@@ -11,6 +13,32 @@ class PlausibleEventRequest extends FormRequest
         return true;
     }
 
+    /**
+     * The Plausible tracker sends its JSON payload with a text/plain content
+     * type, which Laravel does not parse automatically.
+     */
+    protected function prepareForValidation(): void
+    {
+        if ($this->isJson()) {
+            return;
+        }
+
+        $payload = json_decode($this->getContent(), true);
+
+        if (is_array($payload)) {
+            $this->merge($payload);
+        }
+    }
+
+    protected function failedValidation(Validator $validator): void
+    {
+        if (! $this->expectsJson()) {
+            throw new HttpResponseException(response('Bad Request', 400));
+        }
+
+        parent::failedValidation($validator);
+    }
+
     public function rules(): array
     {
         return [

tests/PlausibleProxyTest.php

@@ -1,5 +1,6 @@
 <?php
 
+use Illuminate\Http\Client\ConnectionException;
 use Illuminate\Support\Facades\Http;
 
 it('fetches plausible script and caches it', function () {
@@ -145,3 +146,56 @@ it('rejects invalid props', function () {
         'p' => 'not-json',
     ])->assertStatus(422)->assertJsonValidationErrors(['p']);
 });
+
+it('accepts events sent as text/plain by the plausible tracker', function () {
+    Http::fake([
+        'https://plausible.io/api/event' => Http::response('ok', 202),
+    ]);
+
+    $this->call('POST', '/api/event', [], [], [], ['CONTENT_TYPE' => 'text/plain'], json_encode([
+        'n' => 'pageview',
+        'u' => 'https://example.com/page',
+        'd' => 'example.com',
+        'r' => null,
+    ]))->assertStatus(202);
+
+    Http::assertSent(fn ($request) => $request->url() === 'https://plausible.io/api/event'
+        && $request['n'] === 'pageview'
+        && $request['u'] === 'https://example.com/page'
+        && $request['d'] === 'example.com');
+});
+
+it('responds with 400 for invalid text/plain events', function () {
+    Http::fake();
+
+    $this->call('POST', '/api/event', [], [], [], ['CONTENT_TYPE' => 'text/plain'], 'not-json')
+        ->assertStatus(400);
+
+    Http::assertNothingSent();
+});
+
+it('handles a trailing slash in the domain when forwarding events', function () {
+    config()->set('plausible-proxy.domain', 'https://plausible.example.com/');
+
+    Http::fake([
+        'https://plausible.example.com/api/event' => Http::response('ok', 202),
+    ]);
+
+    $this->postJson('/api/event', [
+        'n' => 'pageview',
+        'u' => 'https://example.com/page',
+        'd' => 'example.com',
+    ])->assertStatus(202);
+
+    Http::assertSent(fn ($request) => $request->url() === 'https://plausible.example.com/api/event');
+});
+
+it('responds with 502 when plausible is unreachable', function () {
+    Http::fake(fn () => throw new ConnectionException('Connection refused'));
+
+    $this->postJson('/api/event', [
+        'n' => 'pageview',
+        'u' => 'https://example.com/page',
+        'd' => 'example.com',
+    ])->assertStatus(502);
+});