function Invoke-UnitTest {
    <#
    .SYNOPSIS
        Runs all Pester tests within this repo.

    .DESCRIPTION
        This Cmdlet is used in Drone pipeline to perform the Pester based unit tests.

    .PARAMETER CoverageFormat
        Pester provides the formats JaCoCo ans CoverageGutters. Default is JaCoCo.
        These are the known use cases:
        - JaCoCo -> Used as standard coverage report used by sonar
        - CoverageGutters -> Custom Format to show coverage in VSCode.

    .PARAMETER Verbosity
        This parameter sets the Pester detail level. Default is 'Normal.' Available values are:
        'None', 'Normal', 'Detailed', 'Diagnostic'

    .PARAMETER PassThru
        Tells Invoke-UnitTest to write back the Pester results into your variable / output.

    .PARAMETER Tag
        Pester build in tag filter as string array.

    .PARAMETER ExcludeTag
        Pester build in exclude filter for tests as string array.

    .INPUTS
        [None] No pipeline input.

    .OUTPUTS
        [None] No pipeline output.

    .EXAMPLE
        Invoke-UnitTest
    #>
    [CmdletBinding()]
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute(
        'PSUseConsistentWhitespace',
        '',
        Justification = 'Hashtable bug in ScriptAnalyzer 1.19.1'
    )]
    param (
        [Parameter( Mandatory = $false )]
        [ValidateSet('JaCoCo', 'CoverageGutters')]
        [string]$CoverageFormat = 'JaCoCo',

        [Parameter(Mandatory = $false)]
        [ValidateSet('None', 'Normal', 'Detailed', 'Diagnostic')]
        [string]$Verbosity = 'Normal',

        [Parameter(Mandatory = $false)]
        [switch]$PassThru,

        [Parameter(Mandatory = $false)]
        [ValidateNotNullOrEmpty()]
        [string[]]$Tag,

        [Parameter(Mandatory = $false)]
        [ValidateNotNullOrEmpty()]
        [string[]]$ExcludeTag
    )

    process {
        $Repo = Get-RepoPath
        Write-Verbose -Message '===== Running Pester =====' -Verbose:$VerbosePreference
        $PesterConf = New-PesterConfiguration
        $PesterConf.Run.Path = (Resolve-Path -Path './src').Path
        $PesterConf.Run.Exit = $false
        $PesterConf.Run.PassThru = $true
        $PesterConf.CodeCoverage.Enabled = $true
        $PesterConf.CodeCoverage.OutputFormat = $CoverageFormat
        $PesterConf.TestResult.Enabled = $true
        $CovFiles = Get-ChildItem -Path $Repo.Src.PS1Filter -Recurse | Where-Object {
            $_.BaseName -notmatch '.Tests'
        } | Select-Object -ExpandProperty 'FullName'
        $PesterConf.CodeCoverage.Path = $CovFiles
        $PesterConf.Output.Verbosity = $Verbosity

        # Set Tags if given
        if ($Tag) {
            $PesterConf.Filter.Tag = $Tag
        }
        if ($ExcludeTag) {
            $PesterConf.Filter.ExcludeTag = $ExcludeTag
        }
        $TestResults = Invoke-Pester -Configuration $PesterConf -ErrorAction 'Stop'
        try {
            $ResFileParams = @{
                InputObject = $TestResults
                Path        = $Repo.Build.PesterLogPath
                Type        = 'Pester'
                ErrorAction = 'Stop'
            }
            Write-ResultFile @ResFileParams
        }
        catch {
            Write-FailureStateFile -StepName 'Pester'
            throw ('{0} tests failed!' -f $TestResults.FailedCount)
        }

        if ($TestResults.FailedCount -gt 0) {
            Write-FailureStateFile -StepName 'Pester'
            throw ('{0} tests failed!' -f $TestResults.FailedCount)
        }
        if ($PassThru.IsPresent) {
            Write-Output -InputObject $TestResults
        }
    }
}