From 5314099e532fdbce8c2198e00683645d77ec0a4f Mon Sep 17 00:00:00 2001
From: Zsolt Kolbay <zsolt.kolbay@sonarsource.com>
Date: Fri, 10 Mar 2023 10:38:03 +0100
Subject: [PATCH] Update RSPEC

---
 analyzers/rspec/cs/S3900_c#.html | 57 ++++++++++++++++++++------------
 1 file changed, 35 insertions(+), 22 deletions(-)

diff --git a/analyzers/rspec/cs/S3900_c#.html b/analyzers/rspec/cs/S3900_c#.html
index 57509e5eb08..1de43aa95eb 100644
--- a/analyzers/rspec/cs/S3900_c#.html
+++ b/analyzers/rspec/cs/S3900_c#.html
@@ -1,5 +1,6 @@
-<p>A publicly accessible method can be called from anywhere, which means you should validate parameters to be within the expected constraints. In
-general, checking against <code>null</code> is recommended defensive programming.</p>
+<p>Methods declared as <code>public</code>, <code>protected</code>, or <code>protected internal</code> can be accessed from other assemblies, which
+means you should validate parameters to be within the expected constraints. In general, checking against <code>null</code> is recommended in defensive
+programming.</p>
 <p>This rule raises an issue when a parameter of a publicly accessible method is not validated against <code>null</code> before being
 dereferenced.</p>
 <h2>Noncompliant Code Example</h2>
@@ -9,16 +10,11 @@ <h2>Noncompliant Code Example</h2>
     private MyOtherClass other;
 
     public void Foo(MyOtherClass other)
-    {
-        this.other = other; // Compliant: other not being dereferenced
-    }
-
-    public void Bar(MyOtherClass other)
     {
         this.other = other.Clone(); // Noncompliant
     }
 
-    protected void FooBar(MyOtherClass other)
+    protected void Bar(MyOtherClass other)
     {
         this.other = other.Clone(); // Noncompliant
     }
@@ -31,11 +27,6 @@ <h2>Compliant Solution</h2>
     private MyOtherClass other;
 
     public void Foo(MyOtherClass other)
-    {
-        this.other = other;
-    }
-
-    public void Bar(MyOtherClass other)
     {
         if (other != null)
         {
@@ -43,26 +34,51 @@ <h2>Compliant Solution</h2>
         }
     }
 
-    protected void FooBar(MyOtherClass other)
+    protected void Bar(MyOtherClass other)
     {
         if (other != null)
         {
             this.other = other.Clone();
         }
     }
+
+    public void Baz(MyOtherClass other)
+    {
+        ArgumentNullException.ThrowIfNull(other);
+
+        this.other = other.Clone();
+    }
+
+    public void Qux(MyOtherClass other)
+    {
+        this.other = other; // Compliant: "other" is not being dereferenced
+    }
+
+    private void Xyzzy(MyOtherClass other)
+    {
+        this.other = other; // Compliant: method is not publicly accessible
+    }
 }
 </pre>
 <h2>Exceptions</h2>
-<p>To create a custom null validation method declare an attribute with name <code>ValidatedNotNullAttribute</code> and mark the parameter that is
-validated for null in your method declaration with it:</p>
+<ul>
+  <li> Arguments validated for <code>null</code> via helper methods should be annotated with the <a
+  href="https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/attributes/nullable-analysis#postconditions-maybenull-and-notnull"><code>[NotNull</code></a>] attribute. </li>
+  <li> Method parameters marked with the <code>[NotNull]</code> <a
+  href="https://www.jetbrains.com/help/resharper/Reference__Code_Annotation_Attributes.html#ItemNotNullAttribute">Resharper code annotation
+  attribute</a> are supported as well. </li>
+  <li> To create a custom null validation method declare an attribute with name <code>ValidatedNotNullAttribute</code> and mark the parameter that is
+  validated for null in your method declaration with it: </li>
+</ul>
 <pre>
 using System;
 
+[AttributeUsage(AttributeTargets.Parameter, Inherited=false)]
 public sealed class ValidatedNotNullAttribute : Attribute { }
 
 public static class Guard
 {
-    public static void NotNull&lt;T&gt;([ValidatedNotNullAttribute] this T value, string name) where T : class
+    public static void NotNull&lt;T&gt;([ValidatedNotNullAttribute] T value, [CallerArgumentExpression("value")] string name = "") where T : class
     {
         if (value == null)
             throw new ArgumentNullException(name);
@@ -73,11 +89,8 @@ <h2>Exceptions</h2>
 {
     public static string ToUpper(string value)
     {
-        Guard.NotNull(value, nameof(value));
-        if (value == null)
-        {
-            return value.ToString();
-        }
+        Guard.NotNull(value);
+
         return value.ToUpper(); // Compliant
     }
 }