Update build definition paths by branch

Set-BuildDefinitionPaths.ps1

#requires -version 2.0
[CmdletBinding()]
param (
    [parameter(Mandatory=$true)]
    [string]
    $BuildDefinitionName,
    
    [parameter(Mandatory=$true)]
    [string]
    $ProjectName)


$ErrorActionPreference = 'Stop'
Set-StrictMode -Version Latest

Add-Type -AssemblyName 'Microsoft.TeamFoundation.Client, Version=10.0.0.0, Culture=Neutral, PublicKeyToken=b03f5f7f11d50a3a'
Add-Type -AssemblyName 'Microsoft.TeamFoundation.Build.Client, Version=10.0.0.0, Culture=Neutral, PublicKeyToken=b03f5f7f11d50a3a'

$Collection = New-Object -TypeName Microsoft.TeamFoundation.Client.TfsTeamProjectCollection -ArgumentList
$BuildServer = $Collection.GetService([Microsoft.TeamFoundation.Build.Client.IBuildServer])

if ($BuildDefinitionName.Contains('*')) {
    $BuildServer.QueryBuildDefinitions($ProjectName) |
        Where-Object { 
            $_.Name -like $BuildDefinitionName -and 
            $_.Name -match $BranchNamePattern 
        } |
        ForEach-Object {
            & $MyInvocation.MyCommand.Path $_.Name $ProjectName
        }
    return
}

$Definition = $BuildServer.GetBuildDefinition($ProjectName, $BuildDefinitionName)

$BranchNamePattern = '^(?<branch>[^_]+)_'
if ($Definition.Name -match $BranchNamePattern) {
    $BranchName = $Matches.branch
} else {
    throw "Build definition name '{0}' does not match expected '<branch>_' pattern." -f $Definition.Name
}

$BranchRoot = '$/{0}/Branches/{1}' -f $ProjectName, $BranchName
if ($BranchName -eq 'Trunk') {
    $BranchRoot = '$/{0}/{1}' -f $ProjectName, $BranchName
}
$BranchRootReplacePattern = '^\$/{0}/(?:Trunk|Branches/{1})' -f [Regex]::Escape($ProjectName), [Regex]::Escape($BranchName)

"Using branch root '$BranchRoot' for build '$BuildDefinitionName'."

$Dirty = $false

$Definition.Workspace.Mappings | 
    Where-Object {
        $_.ServerItem -match $BranchRootReplacePattern -and
        -not $_.ServerItem.StartsWith($BranchRoot) 
    } |
    ForEach-Object {
        $Old = $_.ServerItem
        $_.ServerItem = $Old -replace $BranchRootReplacePattern, $BranchRoot
        "Changed workspace mapping '$Old' to '$($_.ServerItem)'."
        $Dirty = $true
    }
    
if ($Definition.Process.ServerPath -match $BranchRootReplacePattern -and
    -not $Definition.Process.ServerPath.StartsWith($BranchRoot)) {
    $Old = $Definition.Process.ServerPath 
    $New = $Old -replace $BranchRootReplacePattern, $BranchRoot
    $Templates = $BuildServer.QueryProcessTemplates($ProjectName)
    $Template = $Templates | 
        Where-Object { $_.ServerPath -eq $New } |
        Select-Object -First 1
    if (-not $Template) {
        $Template = $BuildServer.CreateProcessTemplate($ProjectName, $New)
        $Template.Save()
    }
    $Definition.Process = $Template
    "Changed process template '$Old' to '$New'."
    $Dirty = $true
} 

$Parameters = [xml]$Definition.ProcessParameters
$Old = $Parameters.Dictionary.BuildSettings.ProjectsToBuild 
$Projects = $Old -split ',' |
    ForEach-Object {
        $_ -replace $BranchRootReplacePattern, $BranchRoot
    }
$New = [string]::Join(',', @($Projects))
if ($Old -ne $New) {
    $Parameters.Dictionary.BuildSettings.ProjectsToBuild = $New
    $Definition.ProcessParameters = $Parameters.InnerXml
    "Changed projects to build '$Old' to '$New'."
    $Dirty = $true
}

if ($Dirty) {
    $Definition.Save()
    'Saved.'
}