Tests not running in Test Explorer

Question

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.

Solution 1

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.

Solution 2

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

The tests were then active and runnable in Test Explorer.

Solution 3

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.

Solution 4

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

Solution 5

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.

View more solutions

Comments

[kmhigashioka]

Update your ReSharper. Refer to this stackoverflow.com/questions/16011775/…

[Bernhard Hofmann]

Wouldn't it be wonderful if VS said why a test was not run? Mismatched target platform, missing test adapter, ... :(

[Alex 75]

Where is it mentioned they use ReSharper ?

[JLRishe]

@BernhardHofmann I encountered an issue just like this right now and it turns out that VS was spitting out some error messages in Output > Tests. Important. Frustrating that VS doesn't make them more visible, but that's a place to look in a situation like this.

[Kyle Delaney]

You all might be interested in upvoting this feature request: developercommunity.visualstudio.com/idea/947742/…

[hk1ll3r]

Year is 2020, 5 years since this questions, and still after trying 10 different answers, I couldn't get the nunit tests to run. Creating a console project to run the test code. sigh

[Werner Bisschoff]

So, very simple solution, as none of the answers actually helped... I had an syntax issue in by App.Config file for the test project.... Instead of <?xml version="1.0" encoding="utf-8"?> i had ?xml version="1.0" encoding="utf-8"?>

[Ken Lyon]

@BernhardHofmann Great reminder about Output > Tests. It'd definitely be so much easier if these details were surfaced by the "Not Run" message. i.e. "Not run because..." In my case, I had changed a TestMethod to async but not changed the return type from void to Task. I don't write these often enough to remember! Simple fix when you can find the error message!

[profimedica]

@hk1ll3r, can you share that project bit that does not run?

[Stefan Varga]

I had this error in Output -> Test... "Multiple versions of same extension found. Selecting the highest version. Microsoft.VisualStudio.TestPlatform.MSTest.TestAdapter ..." So I had to update MSTest.TestAdapter and MSTest.TestFramework

[Steve Rakebrandt]

Uninstall Resharper?! I don't think that this is a solution^^

[lukkea]

my previous comment for why I gave this downvote was deleted, so I'll be a little clearer. This isn't a solution for the problem; it's a very temporary fix that doesn't solve the underlying issue. I don't think SO should be a place people should be coming to be told "turn it off and on again", that is knowledge to be learned way before you get here. Please see Joseph Simpson answer for a solution.

[Sascha]

@lukkea I followd Joseph Simpson's answer and confirmed, that all my projects where AnyCpu. I still had the problem described here. For me simply restarting VS helped. That is not the first time VS2012 has these kind of hickups (and not only on my machine). I agree with you, that this isn't a good solution, but if there is nothing wrong with the project, that might be the only help. One should check if cleaning an rebuilding doesn't help either, though.

[Westerlund.io]

This helped me figure that that i needed to install the "NUnit 3 Test Adapter": marketplace.visualstudio.com/…

[Marcel Studer]

this one fixed my issues (switching from mixed platforms to anycpu)

[user2033412]

make sure your testprojects are not netstandard2.0 but netcoreapp2.2

[Palle Due]

In my case it's the exact opposite: Any unit test project, that has the MSTest nuget packages will not run, where as the others do. Strange.

[Palle Due]

Solved: I have a .testsettings file. MSTest packages require a .runsettings file. That's why the tests aren't running.

[anon]

Worked. I really with VS would, you know, give us a clear warning or error message or something.

[Halvard]

+1 I tried to debug a specific test. When I finally ran another, simpler test, then I could debug the specific test. This answer got me to try that.

[JamesHoux]

Temporarily changing the values and changing them back to Any CPU followed by hitting Save fixed it for me. Using VS 2019 Community Edition, in a project that was originally created in VS 2017.

[maylon]

In VS 2019 worked for me to install the adapter from the package manager nuget.org/packages/NUnit3TestAdapter

[Ketobomb]

There is no way to wait for an async void method to finish. Async void is "fire and forget". That's why they cannot be tested.

[Numan]

You saved me that day and a half! I upgraded a 4.5 FW version project and tried removing all unnecessary stuff from packages and ended up in this situation. Thanks!

[Donald.Record]

This was the fix for me, along with restarting VS and deleting the .vs folder. Thank you.

[J_L]

This solved my issue with a .NET Core 3.1 project that refused to execute tests in Test Explorer. Nothing else would fix it but this.

[Éric Bergeron]

After switching from .NET Framework 4.6.2 to .NET Framework 4.7.2 my tests weren't running anymore. After hours of trying, only this solution worked for me.

[StackOverthrow]

VS2019 version: Main Menu -> Test -> Processor Architecture for AnyCPU Projects -> X64.

[Eru]

this fixed my issue as well! :)

[BlueRaja - Danny Pflughoeft]

According to this page you also need to install Microsoft.NET.Test.Sdk from Nuget

[Richard Garside]

If only 'turning it on and off again' would fix all my problems. Still surprising how many it does fix. It's slightly embarrassing that I had to go to stackoverflow to be reminded to do it, but I found this answer useful.

[Bob Lokerse]

In VS 2017 I installed the Extension Nunit 3 Test Adapter and it worked.

[Bob Lokerse]

In VS 2019 I also installed the Extension Nunit 3 Test Adapter and it worked. One note: I also needed to update Visual Studio.

[Samiron]

I wish I could give you a bunch of likes. Thanks a lot.

[Adam Cox]

Note to self: My original MSTest proj ref'd Microsoft.VisualStudio.QualityTools.UnitTestFramework (unsure which version). Resolved issues where method not run (or found) by removing that ref, and installing the latest (v2.1.0) MSTest.TestAdapter (and Framework)

[jr-juxtaposition]

This answer helped me find a similar cause. In my case some test projects had references to Microsoft.VisualStudio.TestPlatform.TestFramework (and did not run) while others had references to Microsoft.VisualStudio.QualaityTools.UnitTestFramework (which were the projects that would run).

[ebyrob]

@AdamCox Is Microsoft.VisualStudio.TestTools.UnitTesting deprecated? I had some tests using this that suddenly quit running as above after re-adding some references to a project they depended on.

[JSON]

@lukka sometimes visual studio is the underlying problem and restarting is the solution

[benmccallum]

@ebyrob, Athanasios' answer below might be relevant. Seems he not only had to upgrade/upgrade to the MSTest.* packages, but also add some dependencies and fix up some binding redirects. Check your warnings output.

[ebyrob]

I think I was experiencing something similar. Eventually I just re-created the project from scratch. Apparently there is a line in the *.csproj file that sets ToolsVersion and bumping mine messed everything up. All I can say is "buyer beware" for MS unit testing and be ready to replace your *.csproj files at a moment's notice this stuff is tightly integrated and very version dependent.

[Nele Kosog]

+1 Thank you! Even with the latest version of VS 2019 16.5.5 I got no message at all that indicated what was wrong. It silently failed.

[Stephan Møller]

"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.)" - Fixed it for me :)

[JP Chapleau]

The facepalming I did when I read this echoed over the land... Thanks for pointing out my stupidity. That worked for me. Upvoted

[pat8719]

Although filed under the "no duh" category. I wish this could get up-voted more as its super obvious that your return type must be Task but easy to forget (because seemingly no other unit test in the world returns anything but void) and sends you down the rabbit hole of fixing your unit test configuration when there is no actual configuration problem. Really wish this just caused a compiler or the very least throws a runtime error.

[benmccallum]

@pat8719, sounds like a good idea for a code analyzer. They're not too hard to write. I just wrote out an xunit fact doing async void Foo() and their analyzers didn't complain, but they could certainly add one that would. cc: @bradwilson

[Iain Carlin]

Thanks, while not directly my problem, the tip to check the console output showed me the error (DBContext Dispose method had an error in it) that was preventing my tests from running.

[Guillaume LaHaye]

I can't believe that this is still a problem... Hopefully, Microsoft with output some kind of warning for that classic snag at one point.

[bkwdesign]

After switching from .NET Framework 4.6.2 to .NET Framework 4.7.2 - I had to delete all the binding redirects in app.config

[Jen]

I had the opposite work for me. Changed from release to debug and got my green ticks

[Christiano Kiss]

This was my problem, too. In VS 2019, it doesn't seem to happen with Xunit, though. But it always occur when using MsTest + async void.

[Bob]

Installing NUnit3TestAdapter worked for me. I'm using VS 2019

[JohnLBevan]

Thanks; I had a similar error; I'd mistyped a Parameter's name in the code I was testing... The test should have failed reporting that error; instead it showed as just not running.

[mike gold]

This fixed it for me as well! I also kept trying and realized from this post that Microsoft seems to be adding the wrong reference to the project when you create an MSTest UnitTest and its not recognized when you run in Visual Studio. Thanks so much for figturing this out!

[Stephen Holt]

@BlueRaja-DannyPflughoeft - the missing Microsoft.NET.Test.Sdk was what was causing me problems. For some reason your comment was collapsed by StackOverflow, so I missed it initially. I've upvoted it now.

[rjacobsen0]

Yes! This was my problem. Thank you! I am using xUnit. I upgraded - <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.3.0" /> + <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.0" /> And it started running my tests.

[Pinte Dani]

This helped me also for MSTest, although I had to install MSTest.TestAdapter NuGet Package instead of NUnit TestAdapter

[Jared Beach]

For me, I had to install the xunit test runner that matched my xunit version. Then restart visual studio. Then it worked

[Guilherme de Jesus Santos]

Exactly the same situation I had issued. Installing xunit.runner.visualstudio fix the problem. My unit tests use xUnit, but Visual Studio said that nUnit Test Adapter could'nt find with that name. So installing this package solved it.

[jkulpe]

I had the same issue. I am in the middle of a code refactor and just a few tests were aborting due to this exception yet 160 of my 316 tests would not run at all. Further, if you run the nunit tests via the command line in PowerShell you'll see the StackOverFlow exception and can use that output to work on the debug

[Russell Dow]

I ran into a similar issue. TestContext needs to be a public property so the test runner can assign a new context to it.

[rud0x1]

I just added "NUnit 3 Test Adaper" in Extensions Manager of my Visual Studio 2019. NUnit adapter has disappeared for some reasons. I remember that I already ran tests a month ago. ))

[Chai]

You are answering to a very old questions that has many answers. Please make sure to contribute something there that adds a new solution or insights.

[Bruno Martins]

I changed target framework from netstandard2.0 to net472 and it worked, thank you @MarcelStuder!!

[Dawood ibn Kareem]

The fact that the tests run in the Resharper test runner indicates that there is no [Ignore] attribute on them.

[JBSnorro]

Yes, for example when upgrading to .NET 6; everything will still compile, but those packages need to be upgraded too

[User1]

This fixed mine.. Just spent ages looking into this!

[Zapnologica]

This worked for me, a Great solution.. Our tests where just doing nothng. We removed those 2 and included the one and it worked perfectly.

[Eric Hirst]

This step appears to be necessary when you manually unload/edit/reload the xxx.test.csproj file in VS2019 using Power Commands.

[Gustaf Liljegren]

Nice. I already had MS Test 2.x, but updating the test packages to the latest version (2.2.7) still fixed it for me.

[rafael matovelle]

This works thanks.

[this.myself]

The Test Output Log helped me to find an Exception deep down in Reactive Call Stack cause I had no mock for an Observable. Testing with Rx is quite challenging sometimes. But worth nonetheless.

[Display name]

I can confirm this works. At least for me. My tests were literally all working and then mid development they stopped and would not start. I tried several of the suggestions above: nothing. updating all the test packages restored function for me.

[Ruli]

You are answering to a very old question that has many answers. Please make sure to contribute something that adds a new solution or insights.

[pbell]

This was the issue for me when using XUnit, I needed to install xunit.runner.visualstudio

[Matthew Conradie]

Thank you - this was my issue

[Jeremy Caney]

There are sixty eight existing answers already, and several already mention this. Please upvote existing answers as a way of validating their feedback, instead of repeating their guidance.

[Joel Wiklund]

I had to close VS, then remove all bin and obj files and vs file, then start VS again, then it worked.

[AyCe]

Only changing the Processor Architecture for AnyCPU Projects in the Test settings did not work, I (also?) had to change the PlatformTarget of the Test project.

[Vinicius Bassi]

Adding the [TestFixture] attribute solved my problem