AutoMapper: InvalidOperationException : ValueFactory attempted to access the Value property of this instance.

This issue was introduced to us after updating to version 5.2.0.

We have a test helper which creates our mapper and adds profiles for us via reflection (we also tried to wrap it with a lock).

private static IMapper MapAutoMapper()
{
	lock (new object())
	{
		var profiles = from assembly in AppDomain.CurrentDomain.GetAssemblies().Where(x => x.FullName.StartsWith("ProjectName."))
					   from profileType in assembly.GetExportedTypes()
					   where typeof(Profile).IsAssignableFrom(profileType) && !profileType.GetTypeInfo().IsAbstract
					   select (Profile)Activator.CreateInstance(profileType);

		var config = new MapperConfiguration(cfg =>
		{
			foreach (var profile in profiles)
			{
				cfg.AddProfile(profile);
			}
		});

		return config.CreateMapper();
	}
}

This often throws the exception down below on our build server (TeamCity). This should be related to a multi-threading issue as Lazy<> is involved which is not thread-safe, right?

System.InvalidOperationException : ValueFactory attempted to access the Value property of this instance.
   at System.Lazy`1.CreateValue()
   at System.Lazy`1.LazyInitValue()
   at AutoMapper.Mappers.ConvertMapper.MapExpression(TypeMapRegistry typeMapRegistry, IConfigurationProvider configurationProvider, PropertyMap propertyMap, Expression sourceExpression, Expression destExpression, Expression contextExpression)
   at AutoMapper.Execution.TypeMapPlanBuilder.MapExpression(TypeMapRegistry typeMapRegistry, IConfigurationProvider configurationProvider, TypePair typePair, Expression sourceParameter, Expression contextParameter, PropertyMap propertyMap, Expression destinationParameter)
   at AutoMapper.Execution.TypeMapPlanBuilder.CreatePropertyMapFunc(PropertyMap propertyMap)
   at AutoMapper.Execution.TypeMapPlanBuilder.TryPropertyMap(PropertyMap propertyMap)
   at AutoMapper.Execution.TypeMapPlanBuilder.CreateAssignmentFunc(Expression destinationFunc, Boolean constructorMapping)
   at AutoMapper.Execution.TypeMapPlanBuilder.CreateMapperLambda()
   at AutoMapper.TypeMap.Seal(TypeMapRegistry typeMapRegistry, IConfigurationProvider configurationProvider)
   at AutoMapper.MapperConfiguration.Seal()
   at AutoMapper.MapperConfiguration..ctor(MapperConfigurationExpression configurationExpression, IEnumerable`1 mappers)
   at AutoMapper.MapperConfiguration..ctor(Action`1 configure)
   at Shared.TestHelper.WithFakes.MapAutoMapper() in C:\Something\Something\Project\Path\WithFakes.cs:line xx

Any ideas?

About this issue

Original URL
State: closed
Created 8 years ago
Comments: 27 (16 by maintainers)

Most upvoted comments

We’ve got a pending PR for this one.

On Thu, Dec 15, 2016 at 9:58 PM, Cindy notifications@github.com wrote:

I am having the same error. It only happens when I try to run all our tests at once. I create a new mapper in each test class, but if all of the tests are running at the same time, then we have multiple threads, each creating a mapper in the test class, so we get this collision. This didn’t happen before upgrading to 5.2.0 - we were able to run all of them at one time just fine. Each of our test classes has code in the constructor that looks like this:

` // create the mapping configuration var config = new MapperConfiguration ( map => { map.AddProfile(); map.AddProfile(); });
        // assert that the configuration is valid
        config.AssertConfigurationIsValid();

        this.mapper = config.CreateMapper();
`

We are quite dependent on AutoMapper in our application, and having it not work in test or on a Build Server when it runs all of the tests for an application at one time, is not really acceptable.

What is the correct way to solve this problem?

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jbogard on Dec 16, 2016

Updating to the latest stable release 6.0.2 fixed my solution. Just wanted to say great work.

AggieCMD on Apr 13, 2017

Try the MyGet build.

lbargaoanu on Dec 19, 2016