admendments as suggested by Wes

eng/common/scripts/Package-Properties.ps1

@@ -105,18 +105,36 @@ function Get-PkgProperties
     return $null
 }
 
+function Get-PackageFolderFromPath($file) {
+    $parts = $file -split "/"
+
+    if ($parts.Length -lt 3) {
+        return ""
+    }
+    return [System.IO.Path]::Combine($parts[0], $parts[1], $parts[2])
+}
+
+# Takes an input diff json file generated from eng/common/scripts/Generate-PR-Diff.ps1
+# On PR builds, this function should be utilized instead of Get-AllPkgProperties.
 function Get-PrPkgProperties([string]$InputDiffJson) {
-    $pkgPropsResult = @()
+    $packagesWithChanges = @()
 
-    Write-Host "In Get-PRPkgProperties function"
+    $allPackageProperties = Get-AllPkgProperties
+    $diff = Get-Content $InputDiffJson | ConvertFrom-Json
+    $targetedFiles = $diff.ChangedFiles
 
-    if ($GetPRPackageInfoFromRepoFn -and (Test-Path "Function:$GetPRPackageInfoFromRepoFn"))
+    foreach($pkg in $allPackageProperties)
     {
-        Write-Host "Attempting to invoke the language one"
-        $pkgPropsResult = &$GetPRPackageInfoFromRepoFn -InputDiffJson $InputDiffJson
+        foreach($file in $targetedFiles)
+        {
+            $pkgFolder = Get-PackageFolderFromPath($file)
+            if ($pkgFolder.EndsWith($pkg.ArtifactName)) {
+                $packagesWithChanges += $pkg
+            }
+        }
     }
 
-    return $pkgPropsResult
+    return $packagesWithChanges
 }
 
 # Takes ServiceName and Repo Root Directory