.NET Code Coverage with OpenCover

I made more progress in improving my Code Quality Pipeline. I added test code coverage reporting to my build script. I am using OpenCover and ReportBuilder to generate the code coverage reports. After getting these two tools from Nuget and Binging a few tips I got this going by writing a batch script to handle the details and having NAnt run the bat in a CodeCoverage target. Here is my bat

REM This is to run OpenCover and ReportGenerator to get test coverage data.
REM OpenCover and ReportGenerator where added to the solution via NuGet.
REM Need to make this a real batch file or execute from NANT.
REM See reference, https://github.com/sawilde/opencover/wiki/Usage, http://blog.alner.net/archive/2013/08/15/code-coverage-via-opencover-and-reportgenerator.aspx
REM Bring dev tools into the PATH.
call "C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\Tools\VsDevCmd.bat"
mkdir .\Reports
REM Restore packages
msbuild .\.nuget\NuGet.targets /target:RestorePackages
REM Ensure build is up to date
msbuild "MyTestSolution.sln" /target:Rebuild /property:Configuration=Release;OutDir=.\Releases\Latest\NET40\
REM Run unit tests
.\packages\OpenCover.4.5.2316\OpenCover.Console.exe -register:user -target:"C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\mstest.exe" -targetargs:"/testcontainer:.\source\tests\MytestProjectFolder\bin\Debug\MyTestProject.dll" -filter:"+[MyTestProjectNamespace]* -[MyTestProjectNamespace.*]*" -mergebyhash -output:.\Reports\projectCoverageReport.xml

REM the filter +[MyTestProjectNamespace]* includes all tested classes, -[MyTestProjectNamespace.*]* excludes items not tested
REM Generate the report
.\packages\ReportGenerator.\ReportGenerator.exe -reports:".\Reports\projectCoverageReport.xml" -targetdir:".\Reports\CodeCoverage" -reporttypes:Html,HtmlSummary^ -filters:-MyTestProject*
REM Open the report - this is just for local running
start .\Reports\CodeCoverage\index.htm


I have integration tests that depend on files in the local file system. These were failing because OpenCover runs the tests from a different path than the one the files are copied to during build. To overcome this I added the DepoloymentItem attribute to my test classes for all of the files I depend on for tests. This attribute will cause the files to be moved to the test run location with the DLLs with OpenCover does its thing.

[DeploymentItem("YourFile.xml")] //Can also be applied to [TestMethod]
public class YourAwesomeTestClass


Another problem I had prevented the database connection strings from being read from the app.config. I was running MSTest with the /noisolation command line option. I removed the option and it worked. It seems like noisolation is there to improve performance of the test run. I don’t see much difference in timing right now and when I hit a wall in the time of my test execution I will revisit…no premature optimization for me. See

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