Helpers/Helpers.ps1

Function Get-TfsRestClient
{
    [CmdletBinding()]
    [OutputType('Microsoft.VisualStudio.Services.WebApi.VssHttpClientBase')]
    Param
    (
        [Parameter(Mandatory=$true, Position=0)]
        [string]
        $Type,

        [Parameter()]
        [object] 
        $Collection
    )

    Process
    {
        return _GetRestClient @PSBoundParameters
    }
}
<#
.SYNOPSIS
    Short description
.DESCRIPTION
    Long description
.EXAMPLE
    PS C:> <example usage>
    Explanation of what the example does
.INPUTS
    Inputs (if any)
.OUTPUTS
    Output (if any)
.NOTES
    General notes
#>

Function Invoke-TfsRestApi
{
    [CmdletBinding()]
    Param
    (
        [Parameter(Position=0, Mandatory=$true, ParameterSetName="Library call")]
        [Alias("Name")]
        [Alias("API")]
        [string]
        $Operation,

        [Parameter(ParameterSetName="Library call")]
        [Alias("Client")]
        [Alias("Type")]
        [string]
        $ClientType,

        [Parameter(ParameterSetName="Library call")]
        [object[]]
        $ArgumentList,

        [Parameter(ParameterSetName="Library call")]
        [string]
        $ErrorMessage,

        [Parameter(ParameterSetName="Library call")]
        [object]
        $Collection,

        [Parameter()]
        [switch]
        $AsTask
    )

    End
    {
        $tpc = Get-TfsTeamProjectCollection -Collection $Collection; if (-not $tpc -or ($tpc.Count -ne 1)) {throw "Invalid or non-existent team project collection $Collection."}

        $client = _GetRestClient $ClientType -Collection $tpc

        $task = $client.$Operation.Invoke($ArgumentList)

        if ($AsTask)
        {
            return $task
        }

        $result = $task.Result; if($task.IsFaulted) { _throw $Message $task.Exception.InnerExceptions }

        return $result
    }
}