Tests not running in Test Explorer

I am currently working on a solution that has currently 32 Unittests. I have been working with the resharper test runner - which works fine. All tests are running, all tests are showing the right test outcome.

However, the tests are not running when using the Visual Studio test explorer.

The Test Explorer is showing all unit tests, but once clicking on "Run All", all tests are getting greyed out and show no result of the test run:

• All test classes are public
• All test classes are having the [TestClass] attribute declared
• All test methods are using the [TestMethod] attribute
• Both the productivity code and the test projects are targeting .NET 3.5.
• I have already tried to clean build my solution, and / or delete all obj, bin, Debug and Release folders

I'd appreciate any hints which would explain this behaviour.

If your projects aren't all AnyCpu then you may also want to check that the following 2 settings match:

1. [Right click test project] -> properties -> Build -> Platform target - e.g. x64

2. [Main Menu] -> Test -> Test Settings -> Default Processor Architecture -> X64

I found that when these didn't match my test project would silently fail to run.

I had to change my async test methods to return Task instead of void.

The tests were then active and runnable in Test Explorer.

If you are using NUnit rather than MSTest then you will need either the NUnit 2 Test Adapter or NUnit 3 Test Adapter for Visual Studio ≥ 2012/2013.

I had the same problem in VS 2017. In my case it solved by restarting VS.

> TLDR: Update the testing packages, look into the output -> test > console

I struggled with this for a day and a half. so here's what I did to solve it:

Symptoms

1. 5 Unit test projects, all discoverable in TestExplorer
2. 2 out of 5 executed properly
3. 3 stating not run at all
4. The problem started after a .net framework update

Investigation

Since all the packages were updated during the .net framework update, I started with the differences between the working and not working projects. The first clue was that all 3 projects were using: MSTest.TestAdapter and MSTest.TestFramework

Naturally I went to the -> Output console -> Test dropdown in VS 2019 and looked at the output. Nothing useful there.

Step one of the solution: Update the MSTest.TestAdapter and MSTest.TestFramework to version 2.0.0

Step two of the solution: Now the Output console -> Test dropdown output started showing one after the other, missing packages and wrong binding redirects

Step three of the solution: Manually add the missing packages. For me those were

1. System.Runtime.Extentions
2. System.Reflection
3. Maybe some more that I'm missing

Step 4 of the solution: Removed/Fixed the unnecessary binding redirects.

I hope this will help someone else.

Check what framework the tests are written against (e.g. nunit, xunit, VS test, etc.) and make sure you've got the correct test adapter/runner extension installed.

For me it was NUnit 3 Test Adapter that was missing and I confirmed the version number required by looking at the nunit.framework dependency version (select the .dll in the Dependencies tree in Solution Explorer and hit F4 to bring up the Properties window).

You can view the error-output of your test runner by opening the Output panel (view-->output) and choosing "tests" from the "Show output from" dropdown

---

Additionally, if you have Resharper installed you can open a test file and hover over the test-circle next to a test to get additional error info

Clicking that will bring you to a window with more detailed information. Alternatively, you can open that window by going to Extensions --> Reshaper --> Windows --> Unit Test Exploration Results

I found that in the project it was not referencing the Microsoft.VisualStudio.QualityTools.UnitTestFramework assembly. Instead, it was referencing Microsoft.VisualStudio.TestPlatform.TestFramework and Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions. When I removed those two references and added the reference to the Microsoft.VisualStudio.QualityTools.UnitTestFramework assembly the tests that were previously marked with the blue exclamation point suddenly became active and started working.

Clean-Rebuild solution worked for me.

I had this issue and for me it was caused by having multiple Test Projects with different versions of :

• MSTest.TestAdapter
• MSTest.TestFramework

Consolidating the nuget packages for the projects so they were the same resolved the issue for me.

Install Nunit3TestAdapter Nuget has solved this problem

Had same issue after clean install of VS 2019. Tests are found but not run with "Unexpected error occurred". Fixed by setting up x64 instead of x86 which was selected by default.

In my case, it was because one test project in my solution had the MSTest.TestFramework and MSTest.TestAdapter nuget packages installed but the others did not. These packages were apparently not required to run tests until one project in the solution had them installed.

The issue was fixed by installing those packages on test projects missing them.

What fixed it for me was upgrading the MS.Test nuget packages

Have tried many options with Visual Studio 2019 Version 16.4.6 and Microsoft.VisualStudio.TestTools.UnitTesting, but for now the only way to run tests successfully was by invoking next command in console

dotnet test

Tests are discovered in Test Explorer but outcome is "Not Run".

Updating Visual Studio did not help.

Have resolved issue with "No test matches the given testcase filter FullyQualifiedName" by running updates to latest version for next packages:

Microsoft.NET.Test.Sdk
MSTest.TestAdapter
MSTest.TestFramework

Setting Processor Architecture for AnyCPU Projects in Test Explorer fixed my issue! See screenshot above.

In my case I had an async void Method and I replaced with async Task ,so the test run as i expected :

    [TestMethod]
    public async  void SendTest(){}

replace with :

    [TestMethod]
    public async  Task SendTest(){}

Had the same symptoms, in my case it was the dotnet core SDK version that was the problem.

The projects was targeting 2.2, and was able to build using 3.0. After installing newest 2.2 SDK version they were able to run.

I am using XUnit and was missing the xunit.runner.visualstudio package. Installing it and my tests ran.

What works for me is to delete the bin folder, then rebuild the project.

I had same symptoms.

Please ensure you have the proper Visual Studio extension installed via Tools - Extensions and Updates. In my case, I had to install XUnit and Specflow from the Online option.

Then clean the solution and rebuild it.

If that still doesn't help, clear your temp directory (search for %temp% in the Start menu search and delete all contents in Temp)

And then finally try uninstalling Resharper which finally fixed my problem.

Here it was the test project was not marked to be built:

Build -> Configuration Manager... -> check build for your test project

I had different version of NUnit (3.11.0) and NunitTestAdapter (3.12.0) nuget packages. When I updated NUnit to 3.12.0, Visual Studio ran tests.

In my case it worked to update the MSTest nuget packages. Could reproduce this problem even on blank MSTest project and updating the packages worked.

This issue is also observed when the test method being run throws a StackOverflowException, making the test runner abort the test run, resulting in the output 0 tests run.

To find the culprit and solve it put a break point at the start of both TestInitialize and TestMethod decorated methods, run the unit test in debug mode, proceed stepping over (F10) until the exception is thrown.

I had a slightly different scenario, but this is the top Google result so I'll answer my issue too. I could run the tests but only about half of them actually ran, with no error output.

Eventually I debugged and stepped through all the tests, and came upon a Stack Overflow Error when creating Test Instances of some models.

In the test instance methods, a child model created a parent and the parent created a child, which created an infinite loop. I removed the parent creation from the child, and now all my tests work!

I changed "Debug" to "Release" and it worked again (Any CPU.)

I had a different solution to get my tests to run. My global packages folder didn't match what was in my .csproj This is what my .csproj looked like:

I had to change my Version to 16.5.0 which i found was installed in my global packages folder. Now my tests are able to run:

I managed to figure out the reason for VS 2019/2022 skipping some tests by running the test cli with blame option:

vstest.console.exe myproject-test.dll /blame

This will generate an xml file with one test with "Completed="False".

In my case, the test host process crashed due to a memory access violation while running that test. The memory access violation was caused by an infinite recursion. You can right-click and debug that certain test.

For me solution was to change the Resharper Unit Testing settings "Default platform architecture" to "x64"

Since I got here with this kind of error I post my problem/solution:

Symptoms:

• Not all tests running, but they didn't depend per project, just some of them were executed.
• All executed ones were green.
• Tech stack: dotnet core / XUnit / FluentAssertions
• All tests detected and updated if it changed.
• By selection or running "Not runned tests" several times they could be executed.

Problem:

There was an error in the code that throw an exception inside another thread. All test assertions passed but it cancelled the test execution. I could see the error in the "Tests output" (NullException).

Check in your project file for references to NUnit of different versions:

In my case, I had installed version 3.11.0 of both NUnit and NUnit3TestAdapter, but there were old references to version 2.6.4, in the project file, that weren't removed with the new installation.

• Solution (Recomended to fix references issues, see docs):

Reinstall NUnit and NUnit3TestAdapter, this fixed the references in my project.

PM> Update-Package NUnit -reinstall
...
PM> Update-Package NUnit3TestAdapter -reinstall

• Solution 2 (In case of reinstalling didn't fix the references):

Uninstall and install NUnit and NUnit3TestAdapter.

PM> Uninstall-Package NUnit
...
PM> Uninstall-Package NUnit3TestAdapter
...
PM> Install-Package NUnit
...
PM> Install-Package NUnit3TestAdapter

There are already a lot of answers to this question, but I had a different scenario and resolution.

We moved functionality of a type being tested from one class to a new class, and as such created a new test class, with the old test class ending up being empty.

Original:

• Old test class

• Test initialize method
• Test methods

Broken:

• Old test class (initializer kept, class kept as placeholder for future)

• Test initialize method (remains, by itself)
• No test methods (the original test methods appear in test runner but don't exist in code so never execute)

• New test class

• Test initialize method
• Test methods

Fixed:

• Old test class (removed)
• New test class

• Test initialize method
• Test methods

Clean the project, close Visual Studio, delete the TestResults folder, then restart VS, then rebuild the project. (This alone might fix your problem, but for me didn't suffice until a deleted the old test class.)

I added <PackageReference Include="NUnit3TestAdapter" Version="3.16.1"> <PrivateAssets>all</PrivateAssets> <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets> </PackageReference>

in my Test.csproj file

Maybe it's an Infinite Loop.

Almost half of my tests were not running. The new changes I made to the code brought the tests to create an infinite loop. After fixing this issue (adding the correct arguments to the right method call) every test ran normally.

Hope this can help anyone - if you're adding new logic to someone else's code try debugging the tests that are not running, maybe you ran into an infinite loop too and VS just stopped the tests.

When using a mix of MSTests and NUnit tests it is possible to mix them. Also, remove other testing frameworks NuGet packages. Remove, Clean solution, Rebuild

This is the case:

[TestFixture]
public class NUnitTestClass
{
    [TestMethod]
    public void MSTestMethod()
    {
         // Will detect it but it won't run
    }
}

With Visual Studio 2019 and test project targeting .NET 5.0 you need to install also xunit.runner.visualstudio. So, your packages should be like in this example:

• xunit (2.4.1)
• xunit.runner.visualstudio (2.4.3)

For me restarting VS2017 did not work. I had to clean sln then found a file with tests that didn't run and run that file only. After that I did run all and it worked normal again.

For me (not quite a solution) it was deselecting the .testsettings file in the Menu [Test]->[Test Settings]->[{current File}] to uncheck the currently used file.

In my case it starts so.

<TestSettings name="Local (with code coverage)" id="e81d13d9-42d0-41b9-8f31-f719648d8d2d" xmlns="http://microsoft.com/schemas/VisualStudio/TeamTest/2010">
  <Deployment>
    <DeploymentItem filename="ConfigurationImportExportTest\Configurations\" />
    <DeploymentItem filename="output\Debug\" />
  </Deployment>
  <Execution>

Apparently the DeploymentItem interferes.

because this was in the Output tab:

Warning: Test Run deployment issue: The assembly or module 'Microsoft.SqlServer.Management.SqlParser' directly or indirectly referenced by deployment item 'output\Debug\' specified by the test settings was not found.
.... more of the same

It does not tell me lots.
Seems like it has to do with the way that all projects put their compilation products in a common \output\Debug folder

however that seems not to hinder it. It puts out another warning mentioning things like

A testsettings or runsettings file with `ForcedLegacyMode = TRUE or VSMDI files are not supported by MSTest-V2.

That seems to stop it.

For me having a property called TestContext in a base class was causing this behavior. For example:

[TestClass]
public abstract class TestClassBase
{
    protected object TestContext { get; private set; }
}

[TestClass]
public class TestClass : TestClassBase
{
    // This method not found
    [TestMethod]
    public void TestCase() {}
}

I can tell from your attributes that you're using MSTest. I had a similar issue: my tests were showing up in the Test Explorer, but when I would try to run them (either by choosing Run All or individually selecting them) they would not.

My problem was that I had created the unit test project manually from an empty .NET Standard Class Library project. I had installed the MSTest.TestFramework NuGet package, but not the MSTest.TestAdapter package. As soon as I installed the adapter package, they ran as expected.

Seems obvious in retrospect, but when you create unit test projects from a template, you take these things for granted.

It is worth mentioning that sometimes NUnit Test Adapter files get corrupted in user folder C:\Users[User]\AppData\Local\Temp\VisualStudioTestExplorerExtensions\NUnit3TestAdapter.3.8.0/build/net35/NUnit3.TestAdapter.dll on Windows 10 and that causes Test Explorer to stop working as it should.

I use VS2019 with .Net 4.7. I installed NUnit extension v3, and changed the Test settings to use X64. My unit test project is Any CPU (would work if I changed it to x64). Now I can debug through my code.

Well i know i am late to the party, but logging my answer here , incase, someone is facing similar issue as mine. I have faced this issue many times. 90% it gets solved by these two steps

project > properties > Build > Platform target > x64 (x32)

Test -> Test Settings > Default Processor Architecture > X64 (x32)

However i found one more common cause. The Solution files often change developer systems and they start pointing to wrong MSTest.TestAdapter. Especially if you are using custom path of nuget packages. I solved this issue by

1. Opening the .csproj file in notepad.

2. Manually correcting reference to MSTest.TestAdapter in import instructions like this.

Please make sure that you choose the right type of project. In my case, I chose the 'Unit Test Project' and I should have 'xUnit Test Project'.

This problem occurred for me when creating a separate test project within Visual Studio 2022 for Mac (preview).

• Repro Steps:
  • Open project in VS 2022
  • right click on solution, add new project
  • tests > nunit > continue
  • Target Framework: NET 6.0
  • Name : random-tests > create
  • VS 2022 for mac inclues a dependency for coverlet.collector - deleting this nuget reference fixed the problem for me.

For me, the issue was my ClassInit() method did not have the right signature.

MSTest class initialization and clean-up attributes

> In particular, note the [ClassInitialize] attribute on the ClassInit() method.

Works:

[ClassInitialize]
public static void ClassInit(TestContext context)
{

}

Did Not Work:

[ClassInitialize]
public void ClassInit(TestContext context)
{

}

or

[ClassInitialize]
public static void ClassInit()
{

}

or

[ClassInitialize]
public void ClassInit()
{

}

For me this was caused by a VS extension for measuring code coverage. It could not reference a particular assembly, and therefore would not run any of the tests. Tests would run fine from the command line using:

dotnet test

To solve this issue, you can opt to have ALL dependencies copied to your Test project debug folder. This ensures that any assemblies can be resolved, as "unused" assemblies are not removed. You can add the following to your Test projects .csprog file:

<PropertyGroup>
    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
</PropertyGroup>

I solved my problem completely different to any of the solutions in here:

Each of my tests made a call to a function which in turn called itself meaning it'd not terminate:

public GoogleIntent CreateIntent(BotPath botpath)
{
    return CreateIntent(botpath);
}

Upgrade your test project to the latest target framework version.

I was using Visual studio 2019 with target framework 4.5 whose support ended in 2016, jumping to 4.7 solved my problem.

I had same issue after update to Visual Studio 16.4.1. Go to Test explorer -> Settings button -> Processor Architecture for AnyCPU projects -> x64

I had similar symptoms as OriolBG with the stack .Net Core/xUnit/FluentAssertions but for me updating the Microsoft.NET.Test.Sdk nuget package for the project did the trick.

I had the same issue, but mine was resolved when I created a working copy on my actual desktop. The issue for me was because of the project folder was located on a network drive, and the dependencies were not able to load across the network drive for some reason. Hope this helps someone.

Right click on the file in your solution explorer and make sure it's build action is set to "C# Compiler"

Solution Explorer --> Right Click File --> "Properties" --> Build Action = "C# Compiler"

Same issue. What was actually happening was that the test running was trying to discover tests in a web site project I have loaded (there was some jasmine specs for angular inside the site).

This was causing the runner to hang trying to load some NodeJS Container

Updating containers from Microsoft.NodejsTools.TestAdapter.TestContainer

I removed the website from the solution (obviously, just the solution, not deleting the website!)

I also had some corrupt configuration data that I had to clear out under the TestStore folder in the .vs directory.

After completing these two steps things magically started working again

Yet another ridiculous case: it somehow happened that two projects in the same solution had the same ProjectId - one of those was a test project and that confused Test Runner.

Removing and readding test projects to the solution changed the ProjectId and fixed the issue.

I was having this issue also and my solution was that I needed to make the test class "public". I created the test class via the Create Unit Tests Wizard through VS2019 and by default it doesn't make it public.

I also faced this issue when I used selenium NUnit test in Visual Studio 2019 Community version 16.9.1. Some of the suggestions was to use older versions. But in my case the actual solution was to add Microsoft.NET.Test.Sdk" Version="16.0.1" package to the project.

Packages included in my project

I chose "Debug Selected Tests" in place of "Run Selected Tests" from test explorer.

Depending on the runtime installed, you may need to select:

[Right click test project] -> properties -> Build -> Platform target - e.g. x86

Setting it as x64 caused a "The framework 'Microsoft.NETCore.App', version '3.1.0' was not found." error in the test error output.

This worked for me in VS2019.

Moved Tests to a new NUnit 3 Test Project. All tests ran as is.

I had a similar problem, tried all posted solutions with no luck. After 2 days eventually figured out that it was OneDrive causing the problem.

Turned off OneDrive, waited a bit, restarted VS, and BAM, was working again!

Make sure you reference your test project with your main application project.

I had this issue, it turns out I left off "public" in front of the test class.

There is a warning for this under "Show output from: Tests"

"TestClass attribute defined on non-public class"

Initially I created test project with .Net library and added xunit and xunit.runner.visualstudio, but that didn't help me to run test cases.

Later created test project with xunit test project template, which automatically added coverlet.collector, Microsoft.NET.Sdk, xunit, xunit.runner.visualstudio nuget packages. Now am able to run test cases.

Was facing this issue, my project is huge and have tons of test cases so I had to figure out this

I uncheked the option "Discover tests in real time from c# and visual basic .net source files"

its under Tools->Options->Test->General

I had the same kind of problem in vs2022, but instead of getting blurred test results, the tests disappeared after running them. Also, no result was shown in the Test Explorer.

I could see that all tests worked in the Output window, but not on the Test Explorer Window where no test was shown.

In my case reinstalling vs2022 solved the problem.

I found a test project ran fine in resharper but ran nothing in vs test. The solution was missing nuget package xunit.runner.visualstudio

I guess the test project was developed by someone with resharper, so they were never aware it did not run in visual studio test explorer.

In my case needs to install Microsoft.NET.Test.Sdk

> TLDR: Make sure all used projects are explicitly referenced

In my case I had a net461 unit test project that compiled fine and also ran fine when run from the Test Explorer explicitly.

When running 'all tests' or running 'not run tests', the test would stop halfway (when it got to the test in question).

Only output in test console:

========== Test run aborted: 270 Tests (270 Passed, 0 Failed, 0 Skipped) run in 5,1 sec ==========

When I converted the unit test project to netcoreapp3.1, the compiler complained about a missing project reference. It was referenced by another referenced project (hence implicitly available).

After the explicit project reference was added, I could revert back to net461, and all unit tests could be run from Test Explorer.

I was able to resolve the problem of non-running Testcases by removing (commenting out) the DeploymentItem attributes to the TestMethods. Environment:

• VS2022
• net462
• MSTest.TestAdapter 2.2.8
• MSTest.TestFramework 2.2.8
• Microsoft.NET.Test.Sdk 16.11.0

Try removing the [Ignore] attribute from above the test method.