Unit Tests not discovered in Visual Studio 2017

Question

I have been struggling with VS 2017 since I installed it  Now it seems Unit Tests will only run from the command line  dotnet test    My project is  NET Core 1 1 1  I have the SDK and the framework update for 1 1 1 installed    I have tried the sample at MSDN  https   msdn microsoft com en-us library ms182532 aspx  which also fails exactly the same way    All NuGet packages for the tests and the main project are current  And both the test project and the main project build without errors  An the tests run successfully from the command line   Has anyone gotten Unit Tests to run in VS 2017  if so how   Thanks  John    Update - Extend  Here is an example of a simple test project that is not working on GitHub  This is an example with xUnit but I have tried NUnit and visual studio built in MS tests  No matter what testing or what changes I make I cannot get the VS test runner to find any tests    What I ve Tried   Deleting VS test cache files DEL  TEMP  VisualStudioTestExplorerExtensions Restarting VS Closing Opening test explorer for xUnit installed Microsoft DotNet InternalAbstractions  see SO post  for NUnit ensure adapter installed and same version  3  as NUnit package test - gt  test settings - gt  default processor architecture is set to x86   The Question Can anyone please provide a working example of a  Net Core 1 1 0 solution in VS2017   csproj project files  where the VS test explorer successfully finds the unit tests OR show me the issue in the example given

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On my case none of the above help to me  But  i downgrade NUNit3TestAdapter to version 3 8 0  then upgrade to the latest  3 10 0

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In my case  the problem was that the project type was set to static library  lib   and it should be a dynamic library  dll

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Forgetting to make the test class public prevents the test methods inside to be discovered  I had a default xUnit project and deleted the sample UnitTest1 cs  replacing it with a controller test class  with a couple of tests  but none were found  Long story short  after updating xUnit  Test Sdk  xUnit runner packages and rebuilding the project  I encountered a build error   Error xUnit1000 Test classes must be public  Thankfully  the updated version threw this exception to spare me some trouble  Modifying the test class to be public fixed my issue

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Solution was removing my app config file from my unit test project  The tests will re-appear   This file referenced some dll s in the bindingredirects that were not actually present in the project references  Re-add the assemblybindings that are strictly necessary for your project

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For me  I needed to run this  which updated all the nunit adapter links for the unit test projects  Install-Package Nunit3TestAdapter

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For me  the issue was that I mistakenly placed test cases in an internal class  TestClass  internal class TestLib      That was causing test cases not being identified

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For me was easier to create a new test project that works perfectly fine with Visual Studio 2017    and just copy the test files  add references  and NuGet packages as required

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The Issue  The problem is that Visual Studio is getting  confused  over the dotnet core versions on the machine  When I went to control panel -  uninstall programs I had 8 different dotnet core SDK s and Runtimes installed  This was somehow causing VS to silently have an error when trying to find tests   Validate The Issue  You can validate the issue by going to the command line and getting the version of dotnet your on   dotnet --version  If you see anything except the latest version you have installed then your machine has some mismatch and is not using the correct version  Example   If you have dotnet core 1 0 1 installed but when you get the version at command prompt and it says 1 0 0 thats a problem   The Solution  Delete all the old stuff  I started with only what I though I needed to remove  the oldest dotnet rc versions  but it still gave the wrong version when testing the issue  Eventually I conceded to do a full clean  I        Uninstalled all visual studio applications  on my machine VS2015 and VS2017  Uninstalled all versions of dotnet core  even most recent    After my machine was completely empty of all VS and donet I installed only VS2017  it comes packaged with latest dotnet   I created a xUnit test project and the test explorer found the test immediately SOLVED  This may seem like overkill but I spent two weeks trying to fix this in other ways  If your having the issue just do it  even though it may take you hours to uninstall reinstall items it will probably save you time   References   See  epestic blog post where he gives more detail on fixing the issue

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I had the same issue  My solution was OK but suddenly when I opened the solution I found out the tests are gone   Finally I downgraded Microsoft VisualStudio TestPlatform TestFramework and Microsoft VisualStudio TestPlatform TestFramework Extensions packages to a very old version  using NuGet manager  and test methods showed up  Then I upgraded to latest version and still there were there    So just downgrade and upgrade packages

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In my case  I target the test project to x64 Architecture and the test setting Architecture  test  gt  Default Processor Architecture  changed was set to x86  They didn t match  After setting the test setting Architecture back to x64 and rebuilding  all tests were discovered again

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Just had this problem with visual studio being unable to find my tests  couldn t see the button to run them besides the method  and they weren t picked up by running all tests in the project   Turns out my test class wasn t public  Making it public allowed VS to discover the tests

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I know that OP has listed this on his checklist  but it s easy to overlook that point while doing clean install of Visual Studio 2017 and setting up new project  Apart from NUnit project template and NUnit Framework one needs to install NUnit adaptor separately  e g  using NuGet command Install-Package NUnit3TestAdapter -Version 3 9 0  After that Visual Studio Community 2017 started discovering unit tests without any issues

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For me  changing the TargetFramework in the test project s  csproj file from  lt PropertyGroup gt     lt TargetFramework gt netcoreapp2 0 lt  TargetFramework gt   lt  PropertyGroup gt   to  lt PropertyGroup gt     lt TargetFramework gt net46 lt  TargetFramework gt   lt  PropertyGroup gt   worked

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I had the same issue and got it to work by doing the following   First  close all open Visual Studio instances and delete this folder   TEMP  VisualStudioTestExplorerExtensions  Running tests with Visual Studio  Go to your NuGet package manager and install Microsoft NET Test Sdk  15 3 0-preview-20170425-07  first and then install xunit runner visualstudio  2 3 0-beta1-build1309   See attached NuGet screenshot to see all the packages I had to install to get the latest VS 2017 to detect my tests

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Don t read out of date articles under MSDN   NET Core relevant materials are under docs microsoft com  https   docs microsoft com en-us dotnet articles core testing   Generally speaking you need a  NET Core console app to contain the unit test cases

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At first  i ve tried to use MSTest  After that  i change it to Nunit test  Then i wanted to back MSTest  I removed all nUnit codes and references but Test Explorer did not show MSTest methods  Solution  I removed all mstest nuget references and reinstalled  Done

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I had the same issue when migrating from Visual Studio 2017 to 2019  I had to reinstall Microsoft NET Test Sdk in all my test projects

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For C     As there is no special question for C   tests  but the topic is very much the same  here is what helped me when I had the trouble with test discovery   If you have only installed Desktop development with C    then the solution is to also install Universal Windows Platform development with the optional C   Universal Windows Platform tools  You can select these in the visual studio web installer   Afterwards  rebuild your test project and the test discovery should work   Btw  I created the unit test project in VS2017  It might be important  because some users mentioned  that they had discovery issues in projects  that were migrated from VS2015 to VS2017

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The API for test adapters for  NET Core changed with the release of Visual Studio 2017 and the move from the project json format to the csproj format  This made the existing dotnet-test-  adapters like dotnet-test-nunit obsolete  The adapters have been updated  but the way you set up and run tests in Visual Studio or on the command line with dotnet test requires different references in your test projects  Beware of any documentation you find that reference packages in the dotnet-test-  format because they are outdated  First  your test project must target a specific platform  either  NET Core or  NET Framework  It cannot target  NET Standard even if the code you are testing is  NET Standard  This is because the target of the tests indicates which platform to run the tests under   NET Standard is like a PCL  Portable Class Library  in that it can run on many platforms  Next  you need to add references to Microsoft NET Test Sdk  your test framework of choice and a compatible test adapter  For NUnit  your references will look like this   lt itemgroup gt       lt packagereference Include  quot Microsoft NET Test Sdk quot  Version  quot 15 0 0 quot  gt  lt  packagereference gt       lt packagereference Include  quot NUnit quot  Version  quot 3 7 1 quot  gt  lt  packagereference gt       lt packagereference Include  quot NUnit3TestAdapter quot  Version  quot 3 8 0 quot  gt  lt  packagereference gt   lt  itemgroup gt   A comment above mentions adding   lt ItemGroup gt       lt Service Include  quot  82a7f48d-3b50-4b1e-b82e-3ada8210c358  quot    gt   lt  ItemGroup gt   This isn t strictly required  but can help  It is added automatically to all unit test projects by Visual Studio to help it quickly find projects with tests  If your tests don t appear in Visual Studio  the first thing to try is closing your solution and then re-opening them  There appear to be bugs in Visual Studio not detecting changes to projects when you edit them  For more information  see Testing  NET Core with NUnit in Visual Studio 2017

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In my case  it turned out that I simply had to upgrade my test adapters and test framework  Done   Example using the NuGet Package Manager

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In the case of  NET Framework  in the test project there were formerly references to the following DLLs   Microsoft VisualStudio TestPlatform TestFramework Microsoft VisualStudio TestPlatform TestFramework Extentions   I deleted them and added reference to   Microsoft VisualStudio QualityTools UnitTestFramework   And then all the tests appeared and started working in the same way as before   I tried almost all of the other suggestions above before  but simply re-referencing the test DLLs worked alright   I posted this answer for those who are in my case

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In my case  it was UWP project present in the solution causing the issue   When I unloaded the UWP project  tests were discovered  When I loaded it back  test disappeard again   Try to unload all projects and keep test project only  Ten rebuild solution and test shound appear in Test Runner  Load projects one by one and rebuild solution each time to find out what project are causing the problem  sample repo  VS bug report

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This just worked for me  don t know if it is the result of changing workspaces that corrupted something    Deleting VS test cache files in  TEMP  VisualStudioTestExplorerExtensions and restart VS2017

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Discovery The top answers above did not work for me  restarting  updating to version 1 1 18     I was already updated  deleting the temp files  clearning NuGet cache etc   What I discovered is that I had differing references to MSTest TestAdapter and MSTest Framework in different test projects  my solution has two   One was pointed to 1 1 18 like    packages config  lt package id  quot MSTest TestAdapter quot  version  quot 1 1 18 quot  targetFramework  quot net461 quot    gt   lt package id  quot MSTest TestFramework quot  version  quot 1 1 18 quot  targetFramework  quot net461 quot    gt       but another has the references to 1 1 11  Some of the answers above lead to this discovery when two versions of the libraries showed up in my temp directory   TEMP  VisualStudioTestExplorerExtensions   after restarting Visual Studio  Solution Simply updating my packages config to the 1 1 18 version is what restored my unit tests functionality in VS  It appears that there are some bugs that do not allow side-by-side references of the MSTest libraries  Hope this helps you  More info   Visual Studio 2017 Ent  15 5 6  I had updated from 15 0 1 with hopes to fix this issue  but I had it in both

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In my case the Test Explorer couldn t find my tests after I moved the project to a new solution    The answer was simply that I had a reference to the old MS Test Adapter in my project   I had a duplicate of the line below for version 1 1 11 of the MS Test Adapter in my cs proj file    lt Import Project     packages MSTest TestAdapter 1 1 18 build net45 MSTest TestAdapter props  Condition  Exists     packages MSTest TestAdapter 1 1 18 build net45 MSTest TestAdapter props      gt   To fix the problem    Right click on project and select  Unload Project   Right click project and select  Edit  Remove line that imports old version of adapter  Right click on project and select  Reload Project   Rebuild Solution Project

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I deleted the BIN and OBJ folders for the project   Once I did that  everything worked properly

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In my case  it was a project I had upgraded the test project from an earlier  NET version  in the app config I had assemblybindings to previous versions of the dependant assemblies  After fixing the assembnlybindings in the app config  my tests got discovered

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I was facing the same issue  in my case in order to resolved    I opened the windows console  windows key   cmd   Navigate to the folder where the project was created  Executed the command  dotnet test  it is basically the same test that visual studio executes but when you run it thru console it allows you to see the complete trace  I got this error message  TestClass attribute defined on non-public class MSTest TestController BaseTest  So I went to the test case and mark it as public  build again and my tests are being displayed correctly

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Sometimes changing the namespace of the tests work  I had the folder structure as follows   A     B         D     C   E   The namespace was flat like Tests  lt  name   and they did not show up in the test window  When I changed the namespace to the structure of the directory  all the tests showed up  Now I could revert back to any other namespace structure I want   Do not forget to build your project

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Removing old  dll should help  Clearing temp files located in the  TEMP  directory at C  Users yourusername  AppData Local Temp

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I had trouble with VS 2017 finding my UnitTest as well  It wasn t the exact problem John was asking - but this was the first result in google that I came looking for so I wanted to share my issue   I had a legacy solution coming back from VS2010 going over VS2013  VS2015  Now in VS2017 it seems namespaces for the  TestMethod  Attribute have changed   Before it was using  Microsoft VisualStudio QualityTools UnitTestFramework  Version 10 0 0 0   I created a new Test dll in the project and that one used by default   Microsoft VisualStudio TestPlatform TestFramework  Version 14 0 0 0   So my solution was to create a new UnitTest project from within VS2017  Maybe changing assembly references for the old test project would have worked as well  With the new reference VS2017 did discover those unit tests

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Sometimes  I find if you have stackoverflow exceptions in your unit test code  visual studio will mark that unit test case as not run and will stop running other test cases that follow this case   In this case  you have to find out which case is causing the stackoverflow exception

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Check if the NUnit 3 Test Adapter is enabled  In my case  I already installed it a long time ago  but suddenly it got disabled somehow  Took me quite a while before I decided to check that part

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Be sure that you are using the correct Microsoft NET Test Sdk   lt PackageReference Include  quot Microsoft NET Test Sdk quot  Version  quot 15 0 0 quot    gt   Do not use pre-release ones  Or you have to change to console app  not library   I have the similar issue  but with the latest release  15 0 0   it starts working again  Also  you may have to add   lt ItemGroup gt     lt Service Include  quot  82a7f48d-3b50-4b1e-b82e-3ada8210c358  quot    gt   lt  ItemGroup gt   but I do not think it is nessesary

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I ve tried everything but nothing helped  In my case  I had a solution with several test projects and some of them were using the old ms-test framework so Visual Studio found only those  I installed the test framework packages for all test projects as showed in this answer  then removed the references to the old quality-tools  restarted Visual Studio  and now I can see all tests

[unit-testing] Unit Tests not discovered in Visual Studio 2017

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