From 638bff0ac3cfdd5608b89cfa75973ae8d30bd66b Mon Sep 17 00:00:00 2001
From: KirtiRamchandani <kirtiar15502@gmail.com>
Date: Sun, 24 May 2026 12:49:22 +0530
Subject: [PATCH] Bound member invocation logging argument strings

---
 .../engine/runtime/Operations/MiscOps.cs      | 21 +++++++++++++--
 .../Logging/MemberInvocationLogging.Tests.ps1 | 27 +++++++++++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)
 create mode 100644 test/powershell/engine/Logging/MemberInvocationLogging.Tests.ps1

diff --git a/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs b/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs
index d584666ab62..74d434ed80f 100644
--- a/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs
+++ b/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs
@@ -3657,6 +3657,23 @@ internal static class MemberInvocationLoggingOps
         );
 #endif
 
+        private const int MaxLoggedArgumentStringLength = 4096;
+
+        private static string LimitLoggedArgumentString(string value)
+        {
+            if (value is null || value.Length <= MaxLoggedArgumentStringLength)
+            {
+                return value;
+            }
+
+            string originalLength = value.Length.ToString(CultureInfo.InvariantCulture);
+            return string.Concat(
+                value.AsSpan(0, MaxLoggedArgumentStringLength),
+                "...<truncated; original length: ".AsSpan(),
+                originalLength.AsSpan(),
+                ">".AsSpan());
+        }
+
         private static string ArgumentToString(object arg)
         {
             object baseObj = PSObject.Base(arg);
@@ -3669,7 +3686,7 @@ private static string ArgumentToString(object arg)
             // The comparisons below are ordered by the likelihood of arguments being of those types.
             if (baseObj is string str)
             {
-                return str;
+                return LimitLoggedArgumentString(str);
             }
 
             // Special case some types to call 'ToString' on the object. For the rest, we return its
@@ -3683,7 +3700,7 @@ private static string ArgumentToString(object arg)
                 || baseType == typeof(BigInteger)
                 || baseType == typeof(decimal))
             {
-                return baseObj.ToString();
+                return LimitLoggedArgumentString(baseObj.ToString());
             }
 
             return baseType.FullName;
diff --git a/test/powershell/engine/Logging/MemberInvocationLogging.Tests.ps1 b/test/powershell/engine/Logging/MemberInvocationLogging.Tests.ps1
new file mode 100644
index 00000000000..fe93994ce28
--- /dev/null
+++ b/test/powershell/engine/Logging/MemberInvocationLogging.Tests.ps1
@@ -0,0 +1,27 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+Describe 'Member invocation logging' -Tags 'CI' {
+    BeforeAll {
+        $type = [psobject].Assembly.GetType('System.Management.Automation.MemberInvocationLoggingOps')
+        $argumentToString = $type.GetMethod(
+            'ArgumentToString',
+            [System.Reflection.BindingFlags]'NonPublic, Static')
+    }
+
+    It 'Keeps short string arguments unchanged' {
+        $value = 'short argument'
+
+        $argumentToString.Invoke($null, [object[]]@($value)) | Should -BeExactly $value
+    }
+
+    It 'Limits long string arguments' {
+        $value = 'a' * 5000
+
+        $result = $argumentToString.Invoke($null, [object[]]@($value))
+
+        $result.Length | Should -BeLessThan $value.Length
+        $result.StartsWith(('a' * 4096), [System.StringComparison]::Ordinal) | Should -BeTrue
+        $result | Should -Match '<truncated; original length: 5000>'
+    }
+}