From 358d12ea9300c3225a1e2214a93c04d9c7a8dd58 Mon Sep 17 00:00:00 2001
From: nbkalex <alex.ioan.dragomir@gmail.com>
Date: Thu, 20 Jun 2019 23:22:30 +0300
Subject: [PATCH] Display com method signature with argument names (#9858)

---
 src/System.Management.Automation/engine/COM/ComUtil.cs | 9 +++++++--
 test/powershell/engine/COM/COM.Basic.Tests.ps1         | 8 ++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/System.Management.Automation/engine/COM/ComUtil.cs b/src/System.Management.Automation/engine/COM/ComUtil.cs
index 9ec96bc9f..44e307a69 100644
--- a/src/System.Management.Automation/engine/COM/ComUtil.cs
+++ b/src/System.Management.Automation/engine/COM/ComUtil.cs
@@ -36,7 +36,11 @@ namespace System.Management.Automation
         internal static string GetMethodSignatureFromFuncDesc(COM.ITypeInfo typeinfo, COM.FUNCDESC funcdesc, bool isPropertyPut)
         {
             StringBuilder builder = new StringBuilder();
-            string name = GetNameFromFuncDesc(typeinfo, funcdesc);
+
+            // First value is function name
+            int namesCount = funcdesc.cParams + 1;
+            string[] names = new string[funcdesc.cParams + 1];
+            typeinfo.GetNames(funcdesc.memid, names, namesCount, out namesCount);
 
             if (!isPropertyPut)
             {
@@ -46,7 +50,7 @@ namespace System.Management.Automation
             }
 
             // Append the function name
-            builder.Append(name);
+            builder.Append(names[0]);
             builder.Append(" (");
 
             IntPtr ElementDescriptionArrayPtr = funcdesc.lprgelemdescParam;
@@ -85,6 +89,7 @@ namespace System.Management.Automation
                 else
                 {
                     builder.Append(paramstring);
+                    builder.Append(" " + names[i + 1]);
 
                     if (i < funcdesc.cParams - 1)
                     {
diff --git a/test/powershell/engine/COM/COM.Basic.Tests.ps1 b/test/powershell/engine/COM/COM.Basic.Tests.ps1
index 83dab2256..832b95c53 100644
--- a/test/powershell/engine/COM/COM.Basic.Tests.ps1
+++ b/test/powershell/engine/COM/COM.Basic.Tests.ps1
@@ -48,6 +48,14 @@ try {
             [System.Object]::ReferenceEquals($element, $drives) | Should -BeFalse
             $element | Should -Be $drives.Item($element.DriveLetter)
         }
+
+        It "ToString() should return method paramter names" {
+            $shell = New-Object -ComObject "Shell.Application"
+            $fullSignature = $shell.AddToRecent.ToString()
+
+            $fullSignature | Should -BeExactly "void AddToRecent (Variant varFile, string bstrCategory)"
+        }
+
     }
 
     Describe 'GetMember/SetMember/InvokeMember binders should have more restricted rule for COM object' -Tags "CI" {