TeamCity : NUnit fails to find dependency of target assembly - windows

Question

Windows 10
Visual Studio 2017
TeamCity 2017.1.2
GitHub
I'm working with a VS solution that locally behaves as expected. Main-project has some package dependencies. Test-project has project-ref to main project. VS local compile succeeds. Main-project refs + dependencies are copied to MyProject/bin/debug; test-project refs + dependencies are copied to MyProject.Tests/bin/debug; ReSharper local run of tests succeeds.
However my TC project has problems running tests.
My build-config steps are : pull from GitHub , run Visual Studio (sln) build , trigger NUnit.ConsoleRunner to run tests vs built assembly - which throws a file not found error (can't find package dependency assembly ) that perhaps indicate the build steps needs to save as artifact the dependent assembly and copy it to the test output dir.
However looking at the agent work dir I find the dependency assembly present in both the main-project and the test-project :
C:\TeamCity\buildAgent\work\64f706c42d79250c\{main-project}\bin\Debug\{dependency}.dll
and
C:\TeamCity\buildAgent\work\64f706c42d79250c\{tests-project}\bin\Debug\{dependency}.dll
which indicates that VS build step copied {dependency}.dll into bin as expected.
So why can't NUnit find it ?
[19:27:48][Step 5/5] MyProject.dll
[19:27:48][MyProject.dll] MyProject.UnitTests.MyTest
[19:27:49][MyProject.UnitTests.MyTest] System.IO.FileNotFoundException : Could not load file or assembly 'MyProjectDependency, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.
[19:27:49]
[MyProject.UnitTests.MyTest] at ReferencingCode()
at MyProject.MyClass.Answer() in C:\TeamCity\buildAgent\work\64f706c42d79250c\MyProject\MyClass.cs:line 9
at MyProject.UnitTests.MyTest() in C:\TeamCity\buildAgent\work\64f706c42d79250c\MyProject\UnitTests.cs:line 10
[19:27:51][Step 5/5] Failed tests detected
I'm wondering if the output dirs are different for the VS Build and NUnit steps ? But my agent work dir is identical to my local VS solution dir - so where would TC be locating the NUnit work dir ?

Answer 1

It looks as if you have two completely separate output directories, one under the test project and one under the main project. Your tests, of course, are run in the directory that contains the test assembly.
The output messages seem to say that the main assembly is being copied into the test assembly directory - the reference from the test project must call for a local copy. We can tell that because the test assembly and the main assembly both have entries in your stack trace. The dependent assembly, however, is probably not referenced by your tests, and so does not get copied. At least that's how I read it - verify by looking at the directory contents.
You could solve this by using the same output directory for everything, but that would probably involve changing the directory structure you are using. A simple fix is to add a reference to the dependent assembly to your test project and set local copy true.

Answer 2

For your tests to run, locally or in TeamCity, your test project must have a project reference to the project you are testing. It does not work any other way. How else would it know what to test? So check your references in the test project, and make sure the output is the same place when the build runs as "Debug" and "Release".
On a side note, letting TC do the actual build and test is fine for simple stuff but it's very hard to troubleshoot. I recommend you build a PowerShell script with PSake and create a "Test" task. That way you can run the script locally and TeamCity can use the same script you are running locally.