Why does visual studio 2012 not find my tests?

I had same symptoms, but under different circumstances.

I had to add one additional step to Peter Lamberg's solution — Clean your solution/project.

My unittest project targets x64. When I created the project it was originally targeting x86.

After switching to x64 all my unit tests disappeared.

I had to go to the Test Menu -> Test Setting -Default Processor Architecture -> x64.

They still didn't show up.

Did a build.

Still didn't show up.

Finally did a Clean

Then they showed up.

I find Clean Solution and Clean to be quite useful at getting the solutions to play ball when setting have changed. Sometimes I have to go to the extreme and delete the obj and bin directories and do a rebuild.

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Please add the keyword public to your class definition. Your test class is currently not visible outside its own assembly.

namespace tests {
    [TestClass]
    public class SimpleTest {
        [TestMethod]
        public void Test() {
            Assert.AreEqual("a","a", "same");
        }
    }
}

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This sometimes works.

Check that the processor architecture under Test menu matches the one you use to build the solution.

Test -> Test Settings -> Default Processor Architecture -> x86 / x64

As mentioned in other posts, make sure you have the Test Explorer window open. Test -> Windows -> Test Explorer

Then rebuilding the project with the tests should make the tests appear in Test Explorer.

Edit: As Ourjamie pointed out below, doing a clean build may also help. In addition to that, here is one more thing I encountered:

The "Build" checkbox was unticked in Configuration Manager for a new test project I had created under the solution.

Go to Build -> Configuration Manager. Make sure your test project has build checkbox checked for all solution configurations and solution platforms.

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I have Visual Studio 2012 and i couldn't see the Tests in Test Explorer,

So I installed the following: NUnit Test Adapter

That fixed the issue for me !

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In my recent experience all of the above did not work. My test method

public async void ListCaseReplace() { ... }

was not showing up but compiling fine. When I removed the async keyword the test the showed up in the Test Explorer. This is bacause async void is a 'fire-and-forget' method. Make the method async Task and you will get your test back!

In addition, not having the Test project's configuration set to "Build" will also prevent tests from showing up. Configuration Manager > Check your Test to build.

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Since the project is on a shared drive as the original poster have indicated. VS.NET needs to trust network location before it will load and run your test assemblies. Have a read of this blog post.

To allow VS.NET to load things of a network share one needs to add them (shares) to trusted locations. To add a location to a full trust list run (obviously amend as required for you environment):

 caspol -m -ag 1.2 -url file:///H:/* FullTrust

To verify or list existing trusted locations run:

 caspol -lg

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A problem I've found is that tests don't get found in the Test Explorer (nothing shows up) if the solution is running off a network drive / network location / shared drive

You can fix this by adding an environment variable.

COMPLUS_LoadFromRemoteSources and set its value to 1

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I had the same problem.. In my case it was caused by a private property TestContext.

Changing it to the following helped:

public TestContext TestContext
{
    get;
    set;
}

After cleaning and building the solution (as described in @Ourjamie 's answer), the test methods in the affected test class were available in the Test Explorer.

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I ran into the same issue while trying to open the solution on a network share. No unit test would be detected by Test Explorer in this case. The solution turns out to be:

Control Panel -> Internet Options -> "Security" Tab -> Click "Intranet" and add the server IP address or host name holding the network share to the "Sites" list.

After doing this, I recompiled the solution and now tests appeared. This should be quite similar to the answer made by @BigT.

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Quick check list for solving some common test problems. Make sure that:

Test class and test methods are public Test class has [TestClass] attribute Test methods have [TestMethod] attribute

If this does not help, try cleaning, rebuilding solution and restarting Visual Studio.

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I was getting the error: "Failed to initialize client proxy: could not connect to vstest.discoveryengine.exe."

Try to run Visual Studio as Administrator. That worked for me.

There is another Stack Overflow post discussing this error, and the same solution works for them. The question remains why this works.

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I sometimes get the same symptoms.

What I did is: 1. Closed the Test Explorer window 2. Cleaned the solution 3. Rebuild the solution 4. Relaunched Test Explorer window from Test -> Windows -> Test Explorer.

And I got my test in Test Explorer window.

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From menu bar on top...

Test -> Run -> All Tests

You may also view all tests from Test Explorer (Test -> Windows -> Test Explorer)

Further with VS 2012, if you miss out anything try searching it using Quick Launch bar on top right (Ctrl + Q) "Test"

Hope this helps.

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I found the best way to troubleshoot this issue is to create a .proj msbuild file and add your unit test projects which you hare having an issue into this file and execute the tests using the command line version of mstest. I found a small configuration issue in my app.config which only appeared when running the tests from mstest - otherwise the test project built just fine. Also you will find any indirect reference issues with this method as well. Once you can run the Unit test from the command line using mstest you can then do a clean solution, rebuild solution and your test should be discovered properly.

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In My case it was something else. I had installed a package and then uninstall it and reinstall an earlier version. That left a residual configuration/runtime/asssemblyBinding/dependencyIdentity redirecting in my app.config. I had to correct it. I figured it out by looking at the Output window and selecting "Tests" in the drop down. The error message was there. This was a pain... I hope it helps someone else.

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This is more to help people who end up here rather than answer the OP's question:

Try closing and re-opening visual studio, did the trick for me.

Hope this helps someone.

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I know this is an older question but with Visual Studio 2015 I was having issues where my newly created test class was not being recognized. Tried everything. What ended up being the issue was that the class was not "included in the project". I only found this on restarting Visual Studio and noticing that my test class was not there. Upon showing hidden files, I saw it, as well as other classes I had written, were not included. Hope that helps

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I was experiencing this issue many times when I try to build the solution in a different PC.

I am using NUnit and Specflow as well. By default My test project targets X86 But I have to change this to X64. Steps are 1. Test Menu -> Test Setting -Default Processor Architecture -> x64. 2. Clean Build 3. Build 4. If still tests didn't show up. 5. Go to Tools  Extensions and Updates Then Install NUnit and Specflow libraries 6. Clean Build 7. Build

Then usually test will showed up in Test Editor.

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I've updated VS 2012 to the Latest Update . ie visual studio update 3. That fixed the issue for me.

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For Me the solution was just a little bit less complicated.

I had just brought an existing solution on to my machine (cloned from gitHub) and we do not track the auto-generated .cs files that Visual Studio created. (For each feature file there is a .cs file with the same name)

Opening the solution without having the associated .cs files actually allow me to navigate to the bound methods, so it appeared as if specflow was wired up properly, but I was not able to view the test names in the Test Explorer.

For this problem simply excluding the feature files from the project and then re-including them, forced VS to regenerate these auto generated codebehind files.

After that, I was able to view the tests in the test explorer.

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I had this problem when upgrading my solution from Microsoft Visual Studio 2012 Express for Web to Microsoft Visual Studio 2013.

I had created a Unit Tests project in 2012, and after opening in 2013 the Unit Test project wouldn't show any tests in the tests explorer. Everytime I tried to run or debug tests it failed, saying the following in the output window:

    Failed to initialize client proxy: 
    could not connect to vstest.discoveryengine.x86.exe

I also noticed that on debugging the tests, it was launching an instance of Visual Studio 2012. This clued me into the fact that the Unit Tests project was still referencing 2012. Looking at the test project reference I realised it was targeting the wrong Microsoft Visual Studio Unit Test Framework DLL for this version of Visual Studio:

C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\PublicAssemblies\Microsoft.VisualStudio.QualityTools.UnitTestFramework.dll

I changed the version number from 11.0 to 12.0:

C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\PublicAssemblies\Microsoft.VisualStudio.QualityTools.UnitTestFramework.dll

I rebuilt all and this fixed the issue - all tests were found in the Test Explorer and now all tests are found and running perfectly.

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Check that your test project is not set to Delay sign only in your project properties -> Signing. If it is, deselect it and do a clean rebuild.

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I hit the same problem while trying to open the solution on a network share in VS2013 Ultimate.

I corrected the problem by turning on

Control Panel -> Internet Options -> "Security" Tab -> Click "Local intranet", click on sites and make sure "Automatically detect intranet network" is ticked.

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These are all great answers, but there is one more reason that I know of; I just ran into it. In one of my tests I had a ReSharper message indicating that I had an unused private class. It was a class I'm going to use in an upcoming test. This actually caused all of my tests to disappear.

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Check referenced assemblies for any assemblies that may have "Copy Local" set to "False".

If your test project builds to it's own folder (bin/Debug for example) and the project depends on another assembly and one of those assemblies in the References list is marked Copy Local = "False", the assembly cannot load due to missing dependencies and your tests will not load after a build.

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It looks like NUnit Framework 2.6.4 does not work well with NUnit Test Adapter. In the website it mentions the test adapter will only work with NUnit Framework 2.6.3.

This was my problem: 1. I had downloaded NUnit and NUnit Test Adapter separately through Nuget in the VS2012. Somehow NUnit got updated to 2.6.4 Suddenly i did not see my test cases listed.

Fix:

Uninstall Nuget and Nuget Test adapter a. Go to Tools> Nuget > Nuget Pkg manager > Manage Nuget Pkg for Solution b. List installed packages c. Click manage d. Un-check your projects Install NUnit Test Adapter including NUnit 2.6.3 Framework Clean/Rebuild solution Open Test > Test Explorer > Run All

I see all the test cases

Hope this helps

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None of the solutions here helped me. The tests wouldn't be discovered for one solution whereas another solution referencing the same projects worked fine. I finally solved this by deleting the solutionname.v12.suo file.

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I had same issue, but a bit different.

I was using visual studio 2012. For some reason, only the tests of the initial generated file was running. But tests in another file were not running. Tried out different solutions posted here, did not work.

Finally I figured out that I had a private method in the test class which was the first method inside the class. I just moved the private method after a test method; so now, a method with [TestMethod] attribute is the first method inside the class. Strange, but now it works.

Hope this helps someone someday.

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Tests do not like async methods. Eg:

    [TestMethod]
    public async void TestMethod1()
    {
        TestLib oLib = new TestLib();
        var bTest = await oLib.Authenticate();

    }

After doing this:

    [TestMethod]
    public void TestAuth()
    {
        TestMethod1();
    }

    public async void TestMethod1()
    {
        TestLib oLib = new TestLib();
        var bTest = await oLib.Authenticate();

    }

It saw the test.

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Adding my answer as this is the top result on Google for this.

I'm using Visual Studio 2015 and (unknowingly - I just ran Install-Package NUnit) installed the NUnit3 package NuGet to my test project. I already had the NUnit Test Adapter extension installed, and my tests were still not showing up.

Installing the NUnit3 Test Adapter through Tools > Extensions and Updates fixed this for me.

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