使用 .NET Core MSTest 运行单元测试：“未找到以下 TestContainer...”

Question

I've searched high and low and can't find answer to this Exception. This question is the main one to come up when I search, but it doesn't address this issue.

[7/8/2018 6:22:22 PM Informational] Executing test method 'CoreScraper.FlyerScraper.GetAllCurrentFlyers'
[7/8/2018 6:22:22 PM Error] System.InvalidOperationException: The following TestContainer was not found 'C:\Users\Username\Documents\Visual Studio 2017\Projects\ProductApp\CoreScraper\bin\Debug\netcoreapp2.0\CoreScraper.dll'
   at Microsoft.VisualStudio.TestWindow.Controller.TestContainerProvider.<GetTestContainerAsync>d__61.MoveNext()

"CoreScraper" is the name of the project. When I look in that ...\\netcoreapp2.0\\ folder, the CoreScraper.dll is definitely in there. I am running the test by right-clicking in the test method and selecting "Run Tests". The test ran fine the very first time I ran it, but it has given me this error ever since. I've closed out of Visual Studio and reopened, deleted the contents of bin\\ , cleaned and rebuilt the project, etc.

Answer 1

What worked for me:

Delete folders inside .vs folder.

But you still can't delete that folder ?

Probably because of Live Unit Testing , testhost.exe or testhost.x86.exe process is the cause.

Answer 2

The problem was that the NuGet package Microsoft.NET.Test.Sdk was not installed. Installing this package in the project via the NuGet Package Manager solved the problem.

This wasn't intuitive to me since I have another unit test project that runs fine without the Microsoft.NET.Test.Sdk package, but that project is .NET Framework 4.6.2.

Answer 3

Today I faced similar issue with Visual Studio 2017 for xUnit Tests. My Observations:

1. Issue arise for me when switching between Release/Debug mode.
2. Solution : Restart Visual Studio and it resolved the issue.

Note After some Google/Bing, I discovered everyone got the solution by installing some packages. However in my case everything was working before and hence decided not to install anything additional.

Hope it helps.

Answer 4

As @Marathon55 said installing Microsoft.NET.Test.Sdk solved the issue but in my case i've to install 2 more packages MSTest.TestFramework & MSTest.TestAdapter . might help someone

Answer 5

I'm Running VS2019, Version 16.7.2. I resolved my problem by deleting the hidden TestStore folder ('.vs[solution name]\\v16\\TestStore'). Seems that a unittest project that exists in another branch is cached in that TestStore folder when switching branch.

Answer 6

This is what has happened in my case.

1. My Visual Studio solution has 9 projects
2. I deleted one test project from solution but still remains on disk
3. Delete above test project from disk
4. Visual Studio's Test Explorer still shows tests from the deleted project, but unable to run them (hence showing the error that OP mentioned)
5. Deleting .vs folder ultimately removed all the references of old project. Now the Test Explorer shows expected number of tests.

Answer 7

I had this problem when I added my new test project as a "Class Library" project instead of a "Unit Test Project". It found my tests but couldn't run them.

Fixed it by deleting the class library project and starting over with the new Unit Test Project.

Answer 8

I had this issue. And I tried every answer that is posted here in this question. In my instance, what was wrong - someone modified app.config file incorrectly. As result, the file gained a new configuration section in it but without definition of this section.

Missing <configSections></configSections>

While having <someConfigSection . . . . /> <someConfigSection . . . . />

I simply fixed app.config and test started to work. This is the source of the original suggestion that app.config can be the culprit of this issue

Answer 9

For me the problem resolved when i switched back from release mode to debug mode.

(While using VS2019)

Answer 10

I don't know if this helps anyone, but I encountered this issue with a Specflow project that I was trying to target .net Standard. In the end the only way to fix this problem was to target .net Core instead.

Answer 11

I am using .NET Framework v4.6.1, not .NET Core, but I also had trouble with this exact same error. I followed a combination of the steps provided by the guys / gals up above.

• Install the MSTest.TestAdapter NuGet package
• Install the MSTest.TestFramework NuGet package
• Install the Microsoft.NET.Test.Sdk NuGet package (may not be required?? unsure)
• close all running instances of VS 2019 and delete the vs/ folder
• reopen VS 2019
• rebuild the test project

...and then it just worked. Hope this helps someone!

Answer 12

I have had the same problem with a .NET Core project. Here is how to solve it:

1. create empty folder (any name you want)
2. run command " dotnet new mstest ". This command creates a unit-test project, with all necessary nuget packages! Then you can examine the.csproj file, here it is:

 <Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <TargetFramework>netcoreapp3.1</TargetFramework> <RootNamespace>my_project_unittest</RootNamespace> <IsPackable>false</IsPackable> </PropertyGroup> <ItemGroup> <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.5.0"> <PackageReference Include="MSTest.TestAdapter" Version="2.1.0" /> <PackageReference Include="MSTest.TestFramework" Version="2.1.0" /> <PackageReference Include="coverlet.collector" Version="1.2.0" /> </ItemGroup> </Project>

Answer 13

In my case I was messing with the test project and at some point decided to change the config from:

<Project Sdk="Microsoft.NET.Sdk">

to

<Project Sdk="Microsoft.NET.Sdk.Web">

but later undid the change.. :)

Then I faced the same issue as everyone here.. After doing countless rebuilds, disabling resharper, cleaning caches, folders, downgrading packages, removal of packages, etc.. - I decided to create a new test project and compare the configuration (surprisingly new project's tests worked in debugging mode)!

To make a long story short - check for the Properties folder.. there should be NO such folder for the Test project! The folder was probably created when I changed the SDK version earlier.

After removal of this folder and project rebuild I was finally able to debug the test! No other solution worked.