public/build/Get-PSTSBuildDefinition.ps1

function Get-PSTSBuildDefinition
{
    param(
        [Parameter(ParameterSetName="set1")][string] $project,
        [Parameter(ParameterSetName="set1")][string] $buildId =$null,
        [Parameter(ParameterSetName="set2")][string] $inFile
    )

    process {

        if ($PSCmdlet.ParameterSetName -eq "set1" ) {

            if ($null -ne $buildId ) {
                $content = `
                _PSTSAPI `
                    -project $project `
                    -resource "Build/Definitions" `
                    -apiVersion "api-version=5.1" `
                    -id $buildId `
                    -method "GET"
            }
            else {
                $content = `
                _PSTSAPI `
                    -project $project `
                    -apiVersion "api-version=5.1" `
                    -resource "Build/Definitions" `
                    -method "GET"
            }

            return [BuildDefinition[]]$content.value
        }
        else {
            return $(`
            Get-Content $inFile | `
            Out-String) | `
            ConvertFrom-Json
        }
    }
}