xunit and System.Interactive.Async

Question

I am trying to get the unit tests running in my .NET Core 1.0 solution. When I run an empty test it works fine. However, as soon as I try to create new instance of ApplicationDbContext the test fails with the following exception:

  System.IO.FileLoadException : Could not load file or assembly 'System.Interactive.Async, Version=3.0.0.0, Culture=neutral, PublicKeyToken=94bc3704cddfc263'. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
  Stack Trace:
       at Microsoft.EntityFrameworkCore.Infrastructure.EntityFrameworkServiceCollectionExtensions.AddQuery(IServiceCollection serviceCollection)
       at Microsoft.EntityFrameworkCore.Infrastructure.EntityFrameworkServiceCollectionExtensions.AddEntityFramework(IServiceCollection serviceCollection)
       at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.<>c__DisplayClass4_0.<GetOrAdd>b__1(Int64 k)
       at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
       at Microsoft.EntityFrameworkCore.DbContext..ctor(DbContextOptions options)
(2 more stack trace lines from my code)

Not sure why the System.Interactive.Async is needed at all, but I added it as dependency to my Tests project. The dll does not seem to be copied to bin\Debug\netcoreapp1.0 folder on build, however. If I copy it there manually the effect it exactly the same. Any ideas what else can I do to get it working?

Answer 1

For me this error was being thrown because in my project.json I had correctly added:

"Microsoft.EntityFrameworkCore.SqlServer": "1.0.0-*",

to use core, but I hadn't removed this line which was further down my file between other dependencies:

"EntityFramework.MicrosoftSqlServer": "7.0.0-rc1-final",

Once I deleted that line, I got past this error.

Answer 2

I am using SQLite and Entity Framework Core. I was facing the below exception.

Could not load file or assembly 'System.Interactive.Async, Version=3.0.3000.0, Culture=neutral, PublicKeyToken=94bc3704cddfc263' or one of its dependencies

I have installed all necessary packages but it didn't solve.

There is a package named System.Interactive.Async (Ix Async) which can be installed through Nuget

Then my runtime exception was solved.

Answer 3

For me it was an errant line

EntityFramework.InMemory

in addition to Microsoft.EntityFrameworkCore.InMemory in project.json. Once I deleted, it started working

Answer 4

In my case problem was same as mentioned above - i found forgotten "EntityFramework.MicrosoftSqlServer" dependency in linked project.

To investigate problem, I use my project's project.lock.json. There was 2 packets with System.Interactive.Async.dll - Ix-Async/1.2.5 and System.Interactive.Async/3.0.0.

Then look which packet dependent from Ix-Async (still surfing in project.lock.json) and found that it was EntityFramework.Core/7.0.0-rc1-final . As there was no more packets that depends on EntityFramework.Core I realized that i have EntityFramework.Core in some of my own dependencies (one of my project's project.json)