AutoMapper: After upgrade to 6.2.0 - xUnit test fixtures throw exception

Hi , After upgrade from 6.1.1 to 6.2.0 i get the following “Mapper already initialized. You must call Initialize once per application domain/process.”.

I have a xunit test fixture for Microsoft.AspNetCore.TestHost.TestServer and it used in many tests

at AutoMapper.Mapper.set_Configuration(IConfigurationProvider value) at AutoMapper.Mapper.Initialize(Action1 config) at AutoMapper.ServiceCollectionExtensions.AddAutoMapperClasses(IServiceCollection services, Action1 additionalInitAction, IEnumerable1 assembliesToScan) at My.Startup.ConfigureServices(IServiceCollection services) in C:\My\src\My\Startup.cs:line 37 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at Microsoft.AspNetCore.Hosting.ConventionBasedStartup.ConfigureServices(IServiceCollection services) at Microsoft.AspNetCore.Hosting.Internal.WebHost.EnsureApplicationServices() at Microsoft.AspNetCore.Hosting.Internal.WebHost.BuildApplication() at Microsoft.AspNetCore.Hosting.WebHostBuilder.Build() at Microsoft.AspNetCore.TestHost.TestServer..ctor(IWebHostBuilder builder, IFeatureCollection featureCollection) at My.Tests.Fixtures.TestServerFixture1…ctor() in C:\My\src\My\Tests\Fixtures\TestServerFixture.cs:line 27

About this issue

Original URL
State: closed
Created 7 years ago
Comments: 29 (10 by maintainers)

Most upvoted comments

You don’t have to do that any more, the AutoMapper.Extensions.Microsoft.DependencyInjection project has configuration for this:

AutoMapper.ServiceCollectionExtensions.UseStaticRegistration = false;

That will then do all the other stuff.

Or you can call Mapper.Reset right before you do services.AddAutoMapper

On Fri, Jan 5, 2018 at 3:06 PM, John-Luke Laue notifications@github.com wrote:

@mquelcutti https://github.com/mquelcutti Your solution worked for me. Except I suspect most people will be injecting IMapper, so this is what I have:

services.AddSingleton<IMapper>(new Mapper(new MapperConfiguration(cfg => cfg.AddProfile<OneOfMyProfileClasses>())));

The major downside is that you’ll have to manually add the profiles (with cfg.AddProfile) yourself instead of AutoMapper discovering/adding them for you like it does with services.AddAutoMapper();

— You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub https://github.com/AutoMapper/AutoMapper/issues/2399#issuecomment-355665502, or mute the thread https://github.com/notifications/unsubscribe-auth/AAGYMm4WtvT9IO7lHa96_6ruJRoW6JUOks5tHo7jgaJpZM4QdDZ8 .

jbogard on Jan 5, 2018

I’m running into this issue only when I’m using services.AddAutoMapper(typeof(Startup)) in Startup. I’m only calling it once. This works great when just running the server. However, when I try to use entity framework core database and migrations commands it dies with the “Initialize once” error. If I then remove that line, the database and migrations work fine, but the service will fail with a not initialized error

linuxninja39 on Dec 6, 2017

The issue is we’re running xunit to test an dotnet core aspnet project and the TestServer is being created each time a test runs (because we inject a DbContext which contains data required for the specific test using the InMemory db). So services.AddAutoMapper() has to be called multiple times?

ghost on May 3, 2018

I am having the exact same issue as @david-waterworth I am also using XUnit which I suspect may be the culprit. We need to find a way to fix this.

VictorioBerra on Jul 12, 2018

I didn’t think we were, originally we just called services.AddAutoMapper() which I assumed was creating it’s own instance. But then it started failing so we added Mapper.Reset() before it. Is there an example of how to configure AutoMapper to not use the static version in aspnet core 2.0?

ghost on May 4, 2018

i am using 1700 places where i use Mapper.Initialize, before updating automapper its work fine but now it throws mapper already initialized exception, any solution please?

mrmkamranmalik on Apr 3, 2018