chore: fixes equals implementation

Signed-off-by: Vincent Biret <[email protected]>

Author: baywet

src/Microsoft.OpenApi/Expressions/RuntimeExpression.cs

@@ -78,23 +78,29 @@ public static RuntimeExpression Build(string expression)
         /// </summary>
         public override int GetHashCode()
         {
-            return Expression.GetHashCode();
+            return StringComparer.Ordinal.GetHashCode(Expression);
         }
 
         /// <summary>
         /// Equals implementation for IEquatable.
         /// </summary>
         public override bool Equals(object? obj)
         {
-            return Equals(obj as RuntimeExpression);
+            if (obj == null)
+            {
+                return false;
+            }
+            if (ReferenceEquals(this, obj))
+            {
+                return true;
+            }
+            return obj is RuntimeExpression runtimeExpression && Equals(runtimeExpression);
         }
 
-        /// <summary>
-        /// Equals implementation for object of the same type.
-        /// </summary>
-        public bool Equals(RuntimeExpression? obj)
+        /// <inheritdoc />
+        public bool Equals(RuntimeExpression? other)
         {
-            return obj != null && obj.Expression == Expression;
+            return other is not null && StringComparer.Ordinal.Equals(Expression, other.Expression);
         }
 
         /// <inheritdoc />

test/Microsoft.OpenApi.Tests/PublicApi/PublicApi.approved.txt

@@ -115,7 +115,7 @@ namespace Microsoft.OpenApi.Expressions
         public const string Prefix = "$";
         protected RuntimeExpression() { }
         public abstract string Expression { get; }
-        public bool Equals(Microsoft.OpenApi.Expressions.RuntimeExpression? obj) { }
+        public bool Equals(Microsoft.OpenApi.Expressions.RuntimeExpression? other) { }
         public override bool Equals(object? obj) { }
         public override int GetHashCode() { }
         public override string ToString() { }