平台订单列表锁定订阅：订阅号链接 back 护栏测试

tests/Feature/AdminPlatformOrderIndexCurrentSubscriptionLinkContainsBackTest.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Merchant;
+use App\Models\Plan;
+use App\Models\SiteSubscription;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Arr;
+use Tests\TestCase;
+
+class AdminPlatformOrderIndexCurrentSubscriptionLinkContainsBackTest extends TestCase
+{
+    use RefreshDatabase;
+
+    protected function loginAsPlatformAdmin(): void
+    {
+        $this->seed();
+
+        $this->post('/admin/login', [
+            'email' => 'platform.admin@demo.local',
+            'password' => 'Platform@123456',
+        ])->assertRedirect('/admin');
+    }
+
+    public function test_index_current_subscription_link_should_carry_back_to_platform_orders_index_without_nested_back(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $merchant = Merchant::query()->firstOrFail();
+
+        $plan = Plan::query()->create([
+            'code' => 'po_index_current_sub_back_plan',
+            'name' => '平台订单列表锁定订阅 back 链接测试套餐',
+            'billing_cycle' => 'monthly',
+            'price' => 10,
+            'list_price' => 10,
+            'status' => 'active',
+            'sort' => 10,
+            'published_at' => now(),
+        ]);
+
+        $sub = SiteSubscription::query()->create([
+            'merchant_id' => $merchant->id,
+            'plan_id' => $plan->id,
+            'status' => 'active',
+            'source' => 'manual',
+            'subscription_no' => 'PO_INDEX_CURRENT_SUB_BACK_0001',
+            'plan_name' => $plan->name,
+            'billing_cycle' => $plan->billing_cycle,
+            'period_months' => 1,
+            'amount' => 10,
+            'starts_at' => now(),
+            'ends_at' => now()->addMonth(),
+        ]);
+
+        // 带 back 访问列表页（模拟从其它页面跳回）
+        $res = $this->get('/admin/platform-orders?' . Arr::query([
+            'site_subscription_id' => $sub->id,
+            'status' => 'pending',
+            'back' => '/admin/plans',
+        ]));
+        $res->assertOk();
+
+        // 订阅号链接应携带 back 回到列表页自身（去掉 back query），不应包含嵌套 back
+        $expectedBack = '/admin/platform-orders?' . Arr::query([
+            'site_subscription_id' => $sub->id,
+            'status' => 'pending',
+        ]);
+
+        $expectedSubShowUrl = '/admin/site-subscriptions/' . $sub->id . '?' . Arr::query([
+            'back' => $expectedBack,
+        ]);
+
+        $res->assertSee($expectedSubShowUrl, false);
+        $res->assertDontSee('back%3D', false);
+    }
+}