test(ApiV1Middlewares): add feature tests for middlewares behavior

Includes tests for ETag handling and content negotiation.

tests/Feature/Api/V1/ApiV1MiddlewaresTest.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\Api\V1;
+
+use Presentation\Api\V1\Http\Middlewares\EnsureApiV1AcceptsJson;
+use Presentation\Api\V1\Http\Middlewares\SetApiV1Etag;
+
+covers(
+    EnsureApiV1AcceptsJson::class,
+    SetApiV1Etag::class
+);
+
+describe('API V1 Middlewares Feature Tests', function (): void {
+    it('returns ETag header on 200 GET requests and 304 Not Modified when If-None-Match matches', function (): void {
+        // GIVEN
+        /** @var \Tests\TestCase $this */
+        $response = $this->getJson('/api/v1/employees');
+
+        // THEN
+        $response->assertStatus(200);
+        $etag = $response->headers->get('ETag');
+        expect($etag)->toBeString()->and($etag)->not->toBeEmpty();
+
+        // WHEN: Sending conditional GET with matching ETag
+        $conditionalResponse = $this->withHeaders([
+            'If-None-Match' => (string) $etag,
+        ])->getJson('/api/v1/employees');
+
+        // THEN: Returns 304 Not Modified
+        $conditionalResponse->assertStatus(304);
+        expect($conditionalResponse->getContent())->toBeEmpty();
+    });
+
+    it('returns 406 Not Acceptable when Accept header explicitly excludes JSON', function (): void {
+        // GIVEN
+        /** @var \Tests\TestCase $this */
+        $response = $this->withHeaders([
+            'Accept' => 'text/html',
+        ])->get('/api/v1/employees');
+
+        // THEN
+        $response->assertStatus(406)
+            ->assertHeader('Content-Type', 'application/problem+json');
+
+        /** @var array<string, mixed> $data */
+        $data = json_decode((string) $response->getContent(), true);
+        expect($data['status'])->toBe(406)
+            ->and($data['title'])->toBe('Not Acceptable');
+    });
+
+    it('allows GET /api/v1/openapi route to return YAML spec without forcing JSON or returning 406', function (): void {
+        // GIVEN
+        /** @var \Tests\TestCase $this */
+        $response = $this->withHeaders([
+            'Accept' => 'application/yaml',
+        ])->get('/api/v1/openapi');
+
+        // THEN
+        $response->assertStatus(200)
+            ->assertHeader('Content-Type', 'application/yaml');
+
+        $etag = $response->headers->get('ETag');
+        expect($etag)->toBeString()->and($etag)->not->toBeEmpty();
+    });
+});