Unit Tests Fail With Could not load file or assembly errors when using Entity Framework Core 2.0

[bigswede74]

Description

After upgrading my projects to use Entity Framework Core 2.0 most of my unit tests are failing with various assembly errors. Some of the unit tests use the Entity Framework Core InMemory provider to mock database data.

System.IO.FileLoadException: Could not load file or assembly 'Microsoft.EntityFrameworkCore, Version=2.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'

System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Extensions.Logging.Abstractions, Version=2.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'

System.IO.FileLoadException: Could not load file or assembly 'System.ValueTuple, Version=0.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'

Steps to reproduce

1. Create a project that uses Entity Framework Core 2.0 for data access
2. Create a test project that uses Entity Framework Core 2.0 InMemory provider to mock the data access for testing
3. Use the memory provider to verify data in a unit test
4. Unit test fails with below error

System.IO.FileLoadException: Could not load file or assembly 'System.ValueTuple, Version=0.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'

Expected behavior

UnitTests should pass

Actual behavior

Unit tests fail with below error

System.IO.FileLoadException: Could not load file or assembly 'System.ValueTuple, Version=0.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'

Environment

Visual Studio 2017 15.3.3
Project Console Application targeting .net 4.7 framework
Test Project with NuGetPackages

[AbhitejJohn]

@bigswede74: Could you help us with a project repro please?

[bigswede74]

Hello AbhitejJohn,
Attached is a sample project.
HelloWorld.zip

[AbhitejJohn]

Thanks Brad. Will get back on this.

[bigswede74]

Hello @AbhitejJohn
Any movement on this issue?
Thanks

[AbhitejJohn]

@bigswede74: Looks like a .Net issue reported at dotnet/standard#476 and dotnet/efcore#9046. The workaround with bindingredirects worked for me on the repro you shared.

[bigswede74]

@AbhitejJohn the problem with this fix is when you add the app.config file to a test project the tests disappear from the text explorer and are no longer discoverable.

see issue
https://developercommunity.visualstudio.com/content/problem/32282/test-explorer-doesnt-populate-with-tests.html

[AbhitejJohn]

@bigswede74: That's odd. That issue seems to be talking about a stale config file. This config file Appconfig.zip works for me. Can you give it a shot please?

[bigswede74]

@AbhitejJohn the assembly redirect worked.