Add unit test.

framework/src/Volo.Abp.Core/Volo/Abp/AbpApplicationBase.cs

@@ -23,7 +23,7 @@ public abstract class AbpApplicationBase : IAbpApplication
     public IServiceCollection Services { get; }
 
     public IReadOnlyList<IAbpModuleDescriptor> Modules { get; }
-    
+
     public string ApplicationName { get; }
 
     private bool _configuredServices;
@@ -43,7 +43,7 @@ public abstract class AbpApplicationBase : IAbpApplication
 
         var options = new AbpApplicationCreationOptions(services);
         optionsAction?.Invoke(options);
-        
+
         ApplicationName = GetApplicationName(options);
 
         services.AddSingleton<IAbpApplication>(this);
@@ -147,7 +147,7 @@ public abstract class AbpApplicationBase : IAbpApplication
     public virtual async Task ConfigureServicesAsync()
     {
         CheckMultipleConfigureServices();
-        
+
         var context = new ServiceConfigurationContext(Services);
         Services.AddSingleton(context);
 
@@ -312,7 +312,7 @@ public abstract class AbpApplicationBase : IAbpApplication
 
         _configuredServices = true;
     }
-    
+
     private static string GetApplicationName(AbpApplicationCreationOptions options)
     {
         if (!string.IsNullOrWhiteSpace(options.ApplicationName))
@@ -324,12 +324,12 @@ public abstract class AbpApplicationBase : IAbpApplication
         if (configuration != null)
         {
             var appNameConfig = configuration["ApplicationName"];
-            if (string.IsNullOrWhiteSpace(appNameConfig))
+            if (!string.IsNullOrWhiteSpace(appNameConfig))
             {
                 return appNameConfig;
             }
         }
-        
+
         var entryAssembly = Assembly.GetEntryAssembly();
         if (entryAssembly != null)
         {

framework/test/Volo.Abp.Core.Tests/Volo/Abp/AbpApplication_Initialize_Tests.cs

@@ -1,10 +1,16 @@
-using System.Threading.Tasks;
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using NSubstitute;
 using Shouldly;
 using Volo.Abp.DependencyInjection;
 using Volo.Abp.Modularity;
 using Volo.Abp.Modularity.PlugIns;
 using Xunit;
+using IConfiguration = Castle.Core.Configuration.IConfiguration;
 
 namespace Volo.Abp;
 
@@ -147,8 +153,8 @@ public class AbpApplication_Initialize_Tests
     [Fact]
     public void Should_Set_And_Get_ApplicationName()
     {
-        const string applicationName = "MyApplication";
-        
+        var applicationName = "MyApplication";
+
         using (var application = AbpApplicationFactory.Create<IndependentEmptyModule>(options =>
                {
                    options.ApplicationName = applicationName;
@@ -156,16 +162,49 @@ public class AbpApplication_Initialize_Tests
         {
             application.ApplicationName.ShouldBe(applicationName);
             application.Services.GetApplicationName().ShouldBe(applicationName);
-            
+
             application.Initialize();
-            
+
+            application.ServiceProvider
+                .GetRequiredService<IApplicationNameAccessor>()
+                .ApplicationName
+                .ShouldBe(applicationName);
+        }
+
+        using (var application = AbpApplicationFactory.Create<IndependentEmptyModule>(options =>
+               {
+                   options.Services.ReplaceConfiguration(new ConfigurationBuilder()
+                       .AddInMemoryCollection(new Dictionary<string, string> {{"ApplicationName", applicationName}})
+                       .Build());
+               }))
+        {
+
+            application.ApplicationName.ShouldBe(applicationName);
+            application.Services.GetApplicationName().ShouldBe(applicationName);
+
+            application.Initialize();
+
+            application.ServiceProvider
+                .GetRequiredService<IApplicationNameAccessor>()
+                .ApplicationName
+                .ShouldBe(applicationName);
+        }
+
+        applicationName = Assembly.GetEntryAssembly()?.GetName().Name;
+        using (var application = AbpApplicationFactory.Create<IndependentEmptyModule>())
+        {
+            application.ApplicationName.ShouldBe(applicationName);
+            application.Services.GetApplicationName().ShouldBe(applicationName);
+
+            application.Initialize();
+
             application.ServiceProvider
                 .GetRequiredService<IApplicationNameAccessor>()
                 .ApplicationName
                 .ShouldBe(applicationName);
         }
     }
-    
+
     [Fact]
     public async Task Should_Resolve_Root_Service_Provider()
     {