Script generating a code coverage report with dotCover and later converting it with Report Generator so that Azure DevOps task Publish Code Coverage Results can use it.

dotcover-report-generator-code-coverage-for-azure-devops.ps1

#region Basic configuration variables

# Comment out or remove $dotnetExecutable or $vsTestExecutable depending on needs.
# Adjust paths so that they lead to executables on a build server.
$dotCoverExecutable = 'C:\Program Files\DotCover\dotCover.exe'
$dotnetExecutable = 'C:\Program Files\dotnet\dotnet.exe'
$vsTestExecutable = 'C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\Common7\IDE\Extensions\TestPlatform\vstest.console.exe'
$reportGeneratorExecutable = 'C:\Windows\ServiceProfiles\NetworkService\.dotnet\tools\reportgenerator.exe'

# This pattern will be used to identify test projects. Use array if necessary.
$testProjectPattern = '*Tests.csproj'

# For more info on dotCover assembly filter visit:
# https://www.jetbrains.com/help/dotcover/Running_Coverage_Analysis_from_the_Command_LIne.html#filters.
$dotCoverAssemblyFilter = '+:Module=MyApplication*;'

#endregion

#region Checks if paths to executables are correct

# If you commented or removed any executable paths do the same for apropriate check.
if (-not (Test-Path -Path $dotcoverExecutable)) {
    Throw "Path to DotCover executable is not correct."
}

if (-not (Test-Path -Path $dotnetExecutable)) {
    Throw "Path to dotnet executable is not correct."
}

if (-not (Test-Path -Path $vsTestExecutable)) {
    Throw "Path to vsTest executable is not correct."
}

if (-not (Test-Path -Path $reportGeneratorExecutable)) {
    Throw "Path to Report Generator executable is not correct."
}

#endregion

# If necessary use -Exclude parameter to get full benefits of Get-ChildItem
$testProjectsArguments = @{
    Path = "$(System.DefaultWorkingDirectory)"
    Include = $testProjectPattern
}

$testProjects = Get-ChildItem @testProjectsArguments -Recurse -File

if ($testProjects.count -eq 0) {
    throw "No files matched the $testProjectPattern pattern. The script cannot continue."
}

#region Directory structure creation

<#
    The script will create the following directory structure.

    $(System.DefaultWorkingDirectory)
    └──coverage-report/
       ├── cobertura/  
       └── html/
#>

$reportDirectory = Join-Path -Path "$(System.DefaultWorkingDirectory)" -ChildPath "coverage-report"

if (Test-Path -Path $reportDirectory) {
    Remove-Item -Path ( Join-Path -Path $reportDirectory -ChildPath "*" ) -Recurse
}
else {
    New-Item -Path $reportDirectory -ItemType Directory
}

$reportDirectoryCobertura = Join-Path -Path $reportDirectory -ChildPath "cobertura"
New-Item -Path $reportDirectoryCobertura -ItemType Directory

$reportDirectoryHtml = Join-Path -Path $reportDirectory -ChildPath "html"
New-Item -Path $reportDirectoryHtml -ItemType Directory

#endregion

#region Test coverage with DotCover

foreach ($testProject in $testProjects) {
    
    $reportOutputPathArguments = @{
        Path = $reportDirectory
        ChildPath = "$( $testProject.BaseName )_coverage.xml"
    }
    $reportOutputPath = Join-Path @reportOutputPathArguments
    
    # Again depending on needs remove or comment out unnecessary region below

    #region Arguments and dotCover execution for dotnet

    # CoreInstructionSet is handy when launching dotCover as a service account.
    # Set its value to either x86 or x64 depending on project bitness
    $dotCoverDotnetArguments = @( 
        "cover",
        "/TargetExecutable=$dotnetExecutable",
        "/TargetArguments=test $( $testProject.FullName ) --configuration=$(BuildConfiguration)",
        "/Output=$reportOutputPath",
        "/ReportType=DetailedXML",
        "/Filters=$dotCoverAssemblyFilter"
        "/CoreInstructionSet=x64"
    )
    
    Write-Output "Executing DotCover with following arguments: $dotCoverDotnetArguments."
    
    & "$dotCoverExecutable" @dotCoverDotnetArguments

    #endregion

    #region Arguments and dotCover execution with vsTest
    
    # In case of VsTest the test projects needs to be built before execution of this scrip.
    # The dll file containing tests assemblies needs to be found.
    $testProjectDllArguments = @{
        Path = Join-Path -Path "$( $testProject.DirectoryName )" -ChildPath "\bin\$(BuildConfiguration)"
        Include = "$( $testProject.BaseName ).dll"
    }
    
    $testProjectDll = Get-ChildItem @testProjectDllArguments -Recurse -File
    
    if ($testProjectDll.Count -ne 1) {
        Throw "Make sure that tests projects are built before running this script."
    }

    # CoreInstructionSet is handy when launching dotCover as a service account.
    # Set its value to either x86 or x64 depending on project bitness
    $dotCoverVsTestArguments = @(
        "cover",
        "/TargetExecutable=$vsTestExecutable",
        "/TargetArguments=$( $testProjectDll.FullName )",
        "/Output=$reportOutputPath",
        "/ReportType=DetailedXML",
        "/Filters=$dotCoverAssemblyFilter",
        "/CoreInstructionSet=x64" 
    )
    
    Write-Output "Executing DotCover with following arguments: $dotCoverVsTestArguments."
    
    & "$dotCoverExecutable" @dotCoverVsTestArguments
    
    #endregion

    if ( -not $? ) {
        Throw "At least one unit test haven't passed. The script cannot continue."
    }
}

#endregion

# region Generating reports in html and Cobertura format
$coverageReports = Get-ChildItem -Path $reportDirectory -Include '*_coverage.xml' -File -Recurse

if ($coverageReports.Count -eq 0) {
    Throw "No coverage reports were generated. The script cannot continue."
}

$reportsFilePaths = $coverageReports.FullName -join ';'

$reportGeneratorCoberturaParams = @(
    "-reports: $reportsFilePaths",
    "-targetdir:$reportDirectoryCobertura",
    "-reporttypes:Cobertura"
)

Write-Output "Executing Report Generator with following parameters: $reportGeneratorCoberturaParams."
& "$reportGeneratorExecutable" @reportGeneratorCoberturaParams

$reportGeneratorHtmlParams = @(
    "-reports:$reportsFilePaths",
    "-targetdir:$reportDirectoryHtml",
    "-reporttypes:HtmlInline_AzurePipelines"
)

Write-Output "Executing Report Generator with following parameters: $reportGeneratorHtmlParams."
& "$reportGeneratorExecutable" @reportGeneratorHtmlParams