Throw exception if script for patching TFS task version is called with invalid arguments.

Author: Pascal Berger

src/GitVersionTfsTask/Update-GitVersionTfsTaskVersion.ps1

@@ -5,6 +5,24 @@ param (
 [string] $patch
 )
 
+if ([string]::IsNullOrWhiteSpace($filePath)) {
+    throw "File path needs to be provided."
+}
+
+if ([string]::IsNullOrWhiteSpace($major)) {
+    throw "Major version number needs to be provided."
+}
+
+if ([string]::IsNullOrWhiteSpace($minor)) {
+    throw "Minor version number needs to be provided."
+}
+
+if ([string]::IsNullOrWhiteSpace($patch)) {
+    throw "Patch level needs to be provided."
+}
+
+Write-Host "Set version in '$filePath' to $major.$minor.$patch"
+
 # Get the task.json as a powershell object
 $task = Get-Content -Raw -Path $filePath | ConvertFrom-Json