Public/Test-PowerShellProfileImportsTiPS.ps1

function Test-PowerShellProfileImportsTiPS
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    Param()

    [string[]] $powerShellProfileFilePaths = GetPowerShellProfileFilePaths
    [string[]] $profileFilePathsThatExist =
        $powerShellProfileFilePaths |
        Where-Object { Test-Path -Path $_ -PathType Leaf }

    if ($null -eq $profileFilePathsThatExist -or $profileFilePathsThatExist.Count -eq 0)
    {
        Write-Verbose "No PowerShell profile files exist."
        return $false
    }

    [string] $requiredContentRegex = 'Import-Module\s.*tiPS'
    [Microsoft.PowerShell.Commands.MatchInfo] $results =
        Select-String -Path $profileFilePathsThatExist -Pattern $requiredContentRegex
    if ($null -ne $results)
    {
        Write-Verbose "The tiPS module is imported by the following profile lines:"
        $results | ForEach-Object {
            Write-Verbose " $($_.Path): $($_.Line)"
        }
        return $true
    }

    Write-Verbose "The tiPS module is not imported by any of the PowerShell profiles: $profileFilePathsThatExist"
    return $false
}

# Use a function to get the file paths so we can mock this function for testing.
function GetPowerShellProfileFilePaths
{
    [string[]] $profileFilePaths = @()

    # The $PROFILE variable may not exist depending on the host or the context in which PowerShell was started.
    if (Test-Path -Path variable:PROFILE)
    {
        $profileFilePaths = @(
            $PROFILE.CurrentUserAllHosts
            $PROFILE.CurrentUserCurrentHost
            $PROFILE.AllUsersAllHosts
            $PROFILE.AllUsersCurrentHost
        )
    }

    return ,$profileFilePaths
}