Adding IArgumentCompleterFactory for parameterized ArgumentCompleters (#12605)

test/powershell/Language/Parser/ExtensibleCompletion.Tests.ps1

@@ -175,6 +175,77 @@ function TestFunction
     )
 }
 
+
+class NumberCompleter : IArgumentCompleter
+{
+
+    [int] $From
+    [int] $To
+    [int] $Step
+
+    NumberCompleter([int] $from, [int] $to, [int] $step)
+    {
+        if ($from -gt $to) {
+            throw [ArgumentOutOfRangeException]::new("from")
+        }
+        $this.From = $from
+        $this.To = $to
+        $this.Step = if($step -lt 1) { 1 } else { $step }
+    }
+
+    [IEnumerable[CompletionResult]] CompleteArgument(
+        [string] $CommandName,
+        [string] $parameterName,
+        [string] $wordToComplete,
+        [CommandAst] $commandAst,
+        [IDictionary] $fakeBoundParameters)
+    {
+        $resultList = [List[CompletionResult]]::new()
+        $local:to = $this.To
+        for ($i = $this.From; $i -le $to; $i += $this.Step) {
+            if ($i.ToString().StartsWith($wordToComplete, [System.StringComparison]::Ordinal)) {
+                $num = $i.ToString()
+                $resultList.Add([CompletionResult]::new($num, $num, "ParameterValue", $num))
+            }
+        }
+
+        return $resultList
+    }
+}
+
+class NumberCompletionAttribute : ArgumentCompleterAttribute, IArgumentCompleterFactory
+{
+    [int] $From
+    [int] $To
+    [int] $Step
+
+    NumberCompletionAttribute([int] $from, [int] $to)
+    {
+        $this.From = $from
+        $this.To = $to
+        $this.Step = 1
+    }
+
+    [IArgumentCompleter] Create() { return [NumberCompleter]::new($this.From, $this.To, $this.Step) }
+}
+
+function FactoryCompletionAdd {
+    param(
+        [NumberCompletion(0, 50, Step = 5)]
+        [int] $Number
+    )
+}
+
+Describe "Factory based extensible completion" -Tags "CI" {
+    @{
+        ExpectedResults = @(
+            @{CompletionText = "5"; ResultType = "ParameterValue" }
+            @{CompletionText = "50"; ResultType = "ParameterValue" }
+        )
+        TestInput       = 'FactoryCompletionAdd -Number 5'
+    } | Get-CompletionTestCaseData | Test-Completions
+}
+
 Describe "Script block based extensible completion" -Tags "CI" {
     @{
         ExpectedResults = @(