Attempt to replace OpenCover with coverlet, see rubberduck-vba#5950

RubberduckTests/RubberduckTests.csproj

@@ -94,6 +94,9 @@
     <PackageReference Include="System.Threading.Tasks.Extensions">
       <Version>4.4.0</Version>
     </PackageReference>
+    <PackageReference Include="coverlet.msbuild">
+      <Version>3.1.2</Version>
+    </PackageReference>
   </ItemGroup>
   <Choose>
     <When Condition="'$(VisualStudioVersion)' == '10.0' And '$(IsCodedUITest)' == 'True'">

RubberduckTestsCodeAnalysis/RubberduckTestsCodeAnalysis.csproj

@@ -136,6 +136,9 @@
     <PackageReference Include="System.Xml.XPath.XDocument">
       <Version>4.3.0</Version>
     </PackageReference>
+    <PackageReference Include="coverlet.msbuild">
+      <Version>3.1.2</Version>
+    </PackageReference>
   </ItemGroup>
   <ItemGroup>
     <Compile Update="RubberduckCodeAnalysisUnitTests.cs">

appveyor.yml

@@ -49,7 +49,6 @@ before_build:
   - cinst innosetup --version 6.0.5
   # - cinst codecov
   # - cinst gnupg
-  - cinst opencover.portable
   - nuget restore RubberduckMeta.sln
   - nuget restore Rubberduck.sln
 build_script:
@@ -59,13 +58,9 @@ build_script:
 # TestScript depends on the build matrix to only contain Release cpu
 # Otherwise we might run tests against artifacts that do not exist
 test_script:
-  # we use -returntargetcode to fail the build if tests fail
   # when using test_script, after_test seems to not be executed
-  # Manually select coverage instrumentation using "-register:Path64" to fix coverage generation
-  # Limit number of visits recorded with threshold to improve performance
   - |
-    OpenCover.Console.exe -register:Path64 -returntargetcode -target:"nunit3-console.exe" -threshold:10 -targetargs:".\RubberduckTests\bin\RubberduckTests.dll" -output:".\Rubberduck_Coverage.xml"
-    OpenCover.Console.exe -register:Path64 -returntargetcode -target:"nunit3-console.exe" -threshold:10 -targetargs:".\RubberduckTestsCodeAnalysis\bin\RubberduckTestsCodeAnalysis.dll" -output:".\RubberduckCodeAnalysis_Coverage.xml"
+    dotnet test /p:CollectCoverage:true /p:CoverletOutputFormat=cobertura /p:CoverletOutput=Combined_Coverage.xml
 
 on_success:
   - ps: |
@@ -82,9 +77,6 @@ on_success:
 #        gpg.exe --verify codecov.exe.SHA256SUM.sig codecov.exe.SHA256SUM
 #        If ($(Compare-Object -ReferenceObject  $(($(certUtil -hashfile codecov.exe SHA256)[1], "codecov.exe") -join "  ") -DifferenceObject $(Get-Content codecov.exe.SHA256SUM)).length -eq 0) { echo "SHASUM verified" } Else {exit 1}
 
-  # codecov -f "Rubberduck_Coverage.xml" -n "Main Project Coverage" --flag unit
-  # codecov -f "RubberduckCodeAnalysis_Coverage.xml" -n "Meta Coverage" --flag meta
-
 # Define the installer-name depending on what branch we're building on
 for:
 -