From a25e94fe23e17de6bb833bfd70634f0d499cf216 Mon Sep 17 00:00:00 2001
From: maliming <malimings@gmail.com>
Date: Tue, 7 Apr 2026 10:13:16 +0800
Subject: [PATCH] Address Copilot review: fix nullability and add whitespace
 tests

---
 .../QueryStringTenantResolveContributor.cs       |  2 +-
 ...eMultiTenancy_Without_DomainResolver_Tests.cs | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/framework/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/QueryStringTenantResolveContributor.cs b/framework/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/QueryStringTenantResolveContributor.cs
index 47f3b8eb99..80706a5669 100644
--- a/framework/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/QueryStringTenantResolveContributor.cs
+++ b/framework/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/QueryStringTenantResolveContributor.cs
@@ -21,7 +21,7 @@ public class QueryStringTenantResolveContributor : HttpTenantResolveContributorB
                 var tenantValue = httpContext.Request.Query[tenantKey].ToString();
                 if (!tenantValue.IsNullOrWhiteSpace())
                 {
-                    return Task.FromResult(tenantValue)!;
+                    return Task.FromResult<string?>(tenantValue);
                 }
             }
         }
diff --git a/framework/test/Volo.Abp.AspNetCore.MultiTenancy.Tests/Volo/Abp/AspNetCore/MultiTenancy/AspNetCoreMultiTenancy_Without_DomainResolver_Tests.cs b/framework/test/Volo.Abp.AspNetCore.MultiTenancy.Tests/Volo/Abp/AspNetCore/MultiTenancy/AspNetCoreMultiTenancy_Without_DomainResolver_Tests.cs
index 24cdc3591a..dd648ad725 100644
--- a/framework/test/Volo.Abp.AspNetCore.MultiTenancy.Tests/Volo/Abp/AspNetCore/MultiTenancy/AspNetCoreMultiTenancy_Without_DomainResolver_Tests.cs
+++ b/framework/test/Volo.Abp.AspNetCore.MultiTenancy.Tests/Volo/Abp/AspNetCore/MultiTenancy/AspNetCoreMultiTenancy_Without_DomainResolver_Tests.cs
@@ -86,4 +86,20 @@ public class AspNetCoreMultiTenancy_Without_DomainResolver_Tests : AspNetCoreMul
         var result = await GetResponseAsObjectAsync<Dictionary<string, string>>($"http://abp.io?{_options.TenantKey}=");
         result["TenantId"].ShouldBe("");
     }
+
+    [Fact]
+    public async Task Should_Use_Header_Tenant_Id_When_QueryString_Tenant_Is_Whitespace()
+    {
+        Client.DefaultRequestHeaders.Add(_options.TenantKey, _testTenantId.ToString());
+
+        var result = await GetResponseAsObjectAsync<Dictionary<string, string>>($"http://abp.io?{_options.TenantKey}=%20");
+        result["TenantId"].ShouldBe(_testTenantId.ToString());
+    }
+
+    [Fact]
+    public async Task Should_Fallback_To_Host_When_QueryString_Tenant_Is_Whitespace_And_No_Other_Resolver()
+    {
+        var result = await GetResponseAsObjectAsync<Dictionary<string, string>>($"http://abp.io?{_options.TenantKey}=%20");
+        result["TenantId"].ShouldBe("");
+    }
 }