OpenCover all mstest fail when -register:user is set

Question

Not sure what I am doing wrong while trying to use opencover. I am able to generate reports by running it against executable console apps however whenever I try to run it against actual test code I am in no luck. I have mstest and opencover added to system path.

The library code:

namespace SimpleLibrary
{
    public class SimpleClass
    {

        public string HelloWorld()
        {
            return "HelloWorld!";
        }
    }
}

Test Code :

namespace SimpleTestProj
{  
    [TestClass()]
    public class SimpleClassTest
    {
        [TestMethod()]
        public void HelloWorldTest()
        {
            SimpleClass target = new SimpleClass(); 
            string expected = "HelloWorld!"; 
            string actual;
            actual = target.HelloWorld();
            Assert.AreEqual(expected, actual);
        }
    }
}

With '-register:user' flag the tests fail for some reason:

C:\nickolay\SimpleLibrary\SimpleTestProj\bin\Release>opencover.console.exe  -output:"coverage.xml" -mergebyhash -target:
"mstest.exe" -targetdir:"C:\nickolay\SimpleLibrary\SimpleTestProj\bin\Release" -targetargs:"/testcontainer:SimpleTestPro
j.dll" -filter:+[*]* -register:user
Executing: C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE\mstest.exe
Microsoft (R) Test Execution Command Line Tool Version 10.0.30319.1
Copyright (c) Microsoft Corporation. All rights reserved.

Loading SimpleTestProj.dll...
Starting execution...

Results               Top Level Tests
-------               ---------------
Failed                SimpleTestProj.SimpleClassTest.HelloWorldTest
0/1 test(s) Passed, 1 Failed

Summary
-------
Test Run Failed.
  Failed  1
  ---------
  Total   1
Results file:  C:\nickolay\SimpleLibrary\SimpleTestProj\bin\Release\TestResults\labuser.SDKiosk_SAN-D5RHRCK1 2013-07-24
21_04_25.trx
Test Settings: Default Test Settings
Committing...
Visited Classes 0 of 2 (0)
Visited Methods 0 of 4 (0)
Visited Points 0 of 9 (0)
Visited Branches 0 of 4 (0)

==== Alternative Results (includes all methods including those without corresponding source) ====
Alternative Visited Classes 0 of 2 (0)
Alternative Visited Methods 0 of 6 (0)

Without '-register:user' it says that assemblies were not instrumented:

C:\nickolay\SimpleLibrary\SimpleTestProj\bin\Release>opencover.console.exe  -output:"coverage.xml" -mergebyhash -target:
"mstest.exe" -targetdir:"C:\nickolay\SimpleLibrary\SimpleTestProj\bin\Release" -targetargs:"/testcontainer:SimpleTestPro
j.dll" -filter:+[*]*
Executing: C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE\mstest.exe
Microsoft (R) Test Execution Command Line Tool Version 10.0.30319.1
Copyright (c) Microsoft Corporation. All rights reserved.

Loading SimpleTestProj.dll...
Starting execution...

Results               Top Level Tests
-------               ---------------
Passed                SimpleTestProj.SimpleClassTest.HelloWorldTest
1/1 test(s) Passed

Summary
-------
Test Run Completed.
  Passed  1
  ---------
  Total   1
Results file:  C:\nickolay\SimpleLibrary\SimpleTestProj\bin\Release\TestResults\labuser.SDKiosk_SAN-D5RHRCK1 2013-07-24
21_08_43.trx
Test Settings: Default Test Settings
Committing...
No results - no assemblies that matched the supplied filter were instrumented
    this could be due to missing PDBs for the assemblies that match the filter
    please review the output file and refer to the Usage guide (Usage.rtf)

Mstest successfully runs from the directory :

C:\nickolay\SimpleLibrary\SimpleTestProj\bin\Release>mstest /testcontainer:SimpleTestProj.dll
Microsoft (R) Test Execution Command Line Tool Version 10.0.30319.1
Copyright (c) Microsoft Corporation. All rights reserved.

Loading SimpleTestProj.dll...
Starting execution...

Results               Top Level Tests
-------               ---------------
Passed                SimpleTestProj.SimpleClassTest.HelloWorldTest
1/1 test(s) Passed

Summary
-------
Test Run Completed.
  Passed  1
  ---------
  Total   1
Results file:  C:\nickolay\SimpleLibrary\SimpleTestProj\bin\Release\TestResults\labuser.SDKiosk_SAN-D5RHRCK1 2013-07-24
21_11_00.trx
Test Settings: Default Test Settings

My head is tired of being banged up against a wall here any help is appreciated.

Shaun Wilde Shaun Wilde · Accepted Answer · 2013-08-04T05:32:56

MStest loads the assemblies twice

1) once in the location where the PDB resides 2) in a secondary location (no PDB)

OpenCover does not analyse assemblies without the PDB so to avoid this MSTest behaviour you can use the MSTest switch /noisolation.

Alternatively if that is not an option you can use the OpenCover switch -mergebyhash and OpenCover will instrument an assembly as long as it has already been loaded with a PDB.

OpenCover all mstest fail when -register:user is set

1 Answers