New-Guid add -Empty and -InputObject parameters (#20014)

src/Microsoft.PowerShell.Commands.Utility/commands/utility/NewGuidCommand.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+#nullable enable
+
 using System;
 using System.Management.Automation;
 
@@ -9,16 +11,48 @@ namespace Microsoft.PowerShell.Commands
     /// <summary>
     /// The implementation of the "new-guid" cmdlet.
     /// </summary>
-    [Cmdlet(VerbsCommon.New, "Guid", HelpUri = "https://go.microsoft.com/fwlink/?LinkId=2097130")]
+    [Cmdlet(VerbsCommon.New, "Guid", DefaultParameterSetName = "Default", HelpUri = "https://go.microsoft.com/fwlink/?LinkId=2097130")]
     [OutputType(typeof(Guid))]
-    public class NewGuidCommand : Cmdlet
+    public class NewGuidCommand : PSCmdlet
     {
         /// <summary>
-        /// Returns a guid.
+        /// Gets or sets a value indicating that the cmdlet should return a Guid structure whose value is all zeros.
         /// </summary>
-        protected override void EndProcessing()
+        [Parameter(ParameterSetName = "Empty")]
+        public SwitchParameter Empty { get; set; }
+
+        /// <summary>
+        /// Gets or sets the value to be converted to a Guid.
+        /// </summary>
+        [Parameter(Position = 0, ValueFromPipeline = true, ParameterSetName = "InputObject")]
+        [System.Diagnostics.CodeAnalysis.AllowNull]
+        public string InputObject { get; set; }
+
+        /// <summary>
+        /// Returns a Guid.
+        /// </summary>
+        protected override void ProcessRecord()
         {
-            WriteObject(Guid.NewGuid());
+            Guid? guid = null;
+
+            if (ParameterSetName is "InputObject")
+            {
+                try
+                {
+                    guid = new(InputObject);
+                }
+                catch (Exception ex)
+                {
+                    ErrorRecord error = new(ex, "StringNotRecognizedAsGuid", ErrorCategory.InvalidArgument, null);
+                    WriteError(error);
+                }  
+            }
+            else
+            {
+                guid = ParameterSetName is "Empty" ? Guid.Empty : Guid.NewGuid();
+            }
+
+            WriteObject(guid);
         }
     }
 }

test/powershell/Modules/Microsoft.PowerShell.Utility/New-Guid.Tests.ps1

@@ -2,17 +2,43 @@
 # Licensed under the MIT License.
 Describe "New-Guid" -Tags "CI" {
 
-    It "returns a new guid" {
+    It "Returns a new guid" {
         $guid = New-Guid
         $guid | Should -BeOfType System.Guid
     }
 
-    It "should not be all zeros" {
+    It "Should not be all zeros" {
         $guid = New-Guid
         $guid.ToString() | Should -Not -BeExactly "00000000-0000-0000-0000-000000000000"
     }
 
-    It "should return different guids with each call" {
+    It "Should be all zeros" {
+        $guid = New-Guid -Empty
+        $guid.ToString() | Should -BeExactly "00000000-0000-0000-0000-000000000000"
+    }
+
+    It "Should convert a string to a guid" {
+        $guid1 = New-Guid
+        $guid2 = New-Guid -InputObject $guid1.ToString()
+        $guid3 = New-Guid $guid1.ToString()
+        $guid2 | Should -BeOfType System.Guid
+        $guid1.ToString() | Should -BeExactly $guid2.ToString()
+        $guid1.ToString() | Should -BeExactly $guid3.ToString()
+    }
+
+    It "Should convert a string to a guid, value from pipeline" {
+        $guids = '11c43ee8-b9d3-4e51-b73f-bd9dda66e29c','0f8fad5bd9cb469fa16570867728950e' | New-Guid
+        $guids[0].ToString() | Should -BeExactly '11c43ee8-b9d3-4e51-b73f-bd9dda66e29c'
+        $guids[1].ToString() | Should -BeExactly '0f8fad5b-d9cb-469f-a165-70867728950e'
+    }
+
+    It "Should accept pipeline input" {
+        $guids = 1..10 | foreach-object { [guid]::newguid() }
+        $observed = $guids.Foreach({$_.ToString()}) | New-Guid
+        $observed | Should -Be $guids
+    }
+
+    It "Should return different guids with each call" {
         $guid1 = New-Guid
         $guid2 = New-Guid
         $guid1.ToString() | Should -Not -Be $guid2.ToString()