How can I run an MSBuild task in Powershell on file changed - powershell

Question

I am trying to write something like a CSharp watch task in PowerShell. So, what I want to happen is when a CSharp file changes in a certain directory, it tries to find the csproj file and initiates a build.
Here's what I have currently
function Watch-CSharp-Files() {
set-location "D:\path\to\csharp\files\"
$originalPath = Get-Location
Write-host "Welcome to The Watcher. It keeps track of changing files in this solution directory (including subdirectories) and triggers a build when something changes..."
$existingEvents = get-eventsubscriber
foreach ($item in $existingEvents) {
Unregister-event -SubscriptionId $item.SubscriptionId
write-host "Unsubscribed existing event:" $item.Action.Name
}
$folder = get-location
$filter = '*.*'
$watcher = New-Object IO.FileSystemWatcher $folder, $filter -Property #{IncludeSubdirectories = $true;NotifyFilter = [IO.NotifyFilters]'FileName, LastWrite'}
Register-ObjectEvent $watcher Changed -SourceIdentifier FileChanged -Action {
$path = $Event.SourceEventArgs.FullPath
if ($path -match "(\.cs~|.cs$)") {
write-host "file changed: $path"
Invoke-Expression -Command "Find-And-Build-Project '$path'"
}
}
}
function Find-And-Build-Project([string]$path) {
write-host "BUILD PROJECT REPORTING FOR DUTY"
$pathParts = "$path".Split("\\")
$end = $pathParts.Count - 2 # skip the file name to the parent directory
$testPath = $pathParts[0..$end] -join "\"
write-host "testing path $testPath"
$csproj = Get-ChildItem -path $testPath *.csproj
For ($i = 0; $i -le 10; $i++) {
$newEnd = $end - $i
$newPath = $pathParts[0..$newEnd] -join "\"
$csproj = Get-ChildItem -path $newPath *.csproj
write-host "$i. trying: $newPath, csproj: $csproj"
if ($csproj) {
write-host "found on $i, at $newPath, $csproj"
break
}
}
write-host "Ready: $newPath\$csproj"
$msbuild = "C:\Program Files (x86)\MSBuild\14.0\Bin\MSBuild.exe"
write-host "trying to MSBUILD"
& $msbuild ("$newPath\$csproj", "/target:Build", "/p:configuration=debug", "/verbosity:n")
}
Watch-CSharp-Files
What I have found is that within the function Find-And-Build-Project, the & $msbuild doesn't get invoked. But, I don't understand why.
Any ideas?

Answer 1

Ok, this helped me: https://stackoverflow.com/a/37724701/1326235.
This script targets the saved .cs file (or .cs~tmp[0-9].cs as Visual Studio seems to create), then searches back up the directory tree to find a .csproj file and builds it.
I published the module to the PowerShell Gallery, it's called CSharp-Watch