fix/key location encoding

src/Microsoft.OpenApi/Services/OpenApiVisitorBase.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Linq;
 using System.Net.Http;
 using System.Text.Json.Nodes;
@@ -27,7 +28,16 @@ public abstract class OpenApiVisitorBase
         /// <param name="segment">Identifier for context</param>
         public virtual void Enter(string segment)
         {
-            this._path.Push(segment);
+            if (string.IsNullOrEmpty(segment))
+            {
+                this._path.Push(string.Empty);
+                return;
+            }
+#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP1_0_OR_GREATER
+            this._path.Push(segment.Replace("~", "~0", StringComparison.Ordinal).Replace("/", "~1", StringComparison.OrdinalIgnoreCase));
+#else
+            this._path.Push(segment.Replace("~", "~0").Replace("/", "~1"));
+#endif
         }
 
         /// <summary>
@@ -41,7 +51,7 @@ public virtual void Exit()
         /// <summary>
         /// Pointer to source of validation error in document
         /// </summary>
-        public string PathString { get => "#/" + String.Join("/", _path.Reverse()); }
+        public string PathString { get => "#/" + string.Join("/", _path.Reverse()); }
 
         /// <summary>
         /// Visits <see cref="OpenApiDocument"/>

src/Microsoft.OpenApi/Services/OpenApiWalker.cs

@@ -485,7 +485,7 @@
 
             _visitor.Visit(pathItem);
 
             if (pathItem != null)
             {
                 if (pathItem.Parameters is { } parameters)
                 {
@@ -835,7 +835,7 @@
         /// <summary>
         /// Visits <see cref="IOpenApiMediaType"/> and child objects
         /// </summary>
         internal void Walk(IOpenApiMediaType mediaType, bool isComponent = false)
         {
             if (mediaType == null)
             {
@@ -1297,15 +1297,6 @@
             }
         }
 
-        private static string ReplaceSlashes(string value)
-        {
-#if NET8_0_OR_GREATER
-            return value.Replace("/", "~1", StringComparison.Ordinal);
-#else
-            return value.Replace("/", "~1");
-#endif
-        }
-
         /// <summary>
         /// Adds a segment to the context path to enable pointing to the current location in the document
         /// </summary>
@@ -1315,7 +1306,7 @@
         /// <param name="walk">An action that walks objects within the context.</param>
         private void WalkItem<T>(string context, T state, Action<OpenApiWalker, T> walk)
         {
-            _visitor.Enter(ReplaceSlashes(context));
+            _visitor.Enter(context);
             walk(this, state);
             _visitor.Exit();
         }
@@ -1330,7 +1321,7 @@
         /// <param name="walk">An action that walks objects within the context.</param>
         private void WalkItem<T>(string context, T state, Action<OpenApiWalker, T, bool> walk, bool isComponent)
         {
-            _visitor.Enter(ReplaceSlashes(context));
+            _visitor.Enter(context);
             walk(this, state, isComponent);
             _visitor.Exit();
         }
@@ -1351,7 +1342,7 @@
         {
             if (state != null && state.Count > 0)
             {
-                _visitor.Enter(ReplaceSlashes(context));
+                _visitor.Enter(context);
 
                 foreach (var item in state)
                 {

src/Microsoft.OpenApi/Validations/Rules/OpenApiDocumentRules.cs

@@ -2,6 +2,8 @@
 // Licensed under the MIT license.
 
 using System;
+using System.Collections.Generic;
+using System.Linq;
 
 namespace Microsoft.OpenApi
 {
@@ -74,28 +76,49 @@ private void ValidateSchemaReference(OpenApiSchemaReference reference)
                 {
                     if (reference.RecursiveTarget is null)
                     {
+                        var segments = GetSegments().ToArray();
+                        EnterSegments(segments);
                         // The reference was not followed to a valid schema somewhere in the document
-                        context.Enter(GetSegment());
                         context.CreateWarning(ruleName, string.Format(SRResource.Validation_SchemaReferenceDoesNotExist, reference.Reference.ReferenceV3));
-                        context.Exit();
+                        ExitSegments(segments.Length);
                     }
                 }
                 catch (InvalidOperationException ex)
                 {
-                    context.Enter(GetSegment());
+                    var segments = GetSegments().ToArray();
+                    EnterSegments(segments);
                     context.CreateWarning(ruleName, ex.Message);
-                    context.Exit();
+                    ExitSegments(segments.Length);
                 }
 
-                string GetSegment()
+                void ExitSegments(int length)
                 {
-                    // Trim off the leading "#/" as the context is already at the root of the document
-                    return
-#if NET8_0_OR_GREATER
-                        $"{PathString[2..]}/$ref";
+                    for (var i = 0; i < length; i++)
+                    {
+                        context.Exit();
+                    }
+                }
+
+                void EnterSegments(string[] segments)
+                {
+                    foreach (var segment in segments)
+                    {
+                        context.Enter(segment);
+                    }
+                }
+
+                IEnumerable<string> GetSegments()
+                {
+                    foreach (var segment in this.PathString.Substring(2).Split('/'))
+                    {
+#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP1_0_OR_GREATER
+                        yield return segment.Replace("~1", "/", StringComparison.OrdinalIgnoreCase).Replace("~0", "~", StringComparison.OrdinalIgnoreCase);
 #else
-                        PathString.Substring(2) + "/$ref";
+                        yield return segment.Replace("~1", "/").Replace("~0", "~");
 #endif
+                    }
+                    yield return "$ref";
+                    // Trim off the leading "#/" as the context is already at the root of the document
                 }
             }
         }

test/Microsoft.OpenApi.Tests/Services/OpenApiVisitorBaseTests.cs

@@ -0,0 +1,80 @@
+using System.Collections.Generic;
+using Xunit;
+
+namespace Microsoft.OpenApi.Tests.Services;
+
+public class OpenApiVisitorBaseTests
+{
+    [Fact]
+    public void EncodesReservedCharacters()
+    {
+        // Given
+        var openApiDocument = new OpenApiDocument
+        {
+            Info = new()
+            {
+                Title = "foo",
+                Version = "1.2.2"
+            },
+            Paths = new()
+            {
+            },
+            Components = new()
+            {
+                Schemas = new Dictionary<string, IOpenApiSchema>()
+                {
+                    ["Pet~"] = new OpenApiSchema()
+                    {
+                        Type = JsonSchemaType.Object
+                    },
+                    ["Pet/"] = new OpenApiSchema()
+                    {
+                        Type = JsonSchemaType.Object
+                    },
+                }
+            }
+        };
+        var visitor = new LocatorVisitor();
+
+        // When
+        visitor.Visit(openApiDocument);
+
+        // Then
+        Assert.Equivalent(
+            new List<string>
+            {
+                "#/components/schemas/Pet~0",
+                "#/components/schemas/Pet~1"
+            }, visitor.Locations);
+    }
+
+    private class LocatorVisitor : OpenApiVisitorBase
+    {
+        public List<string> Locations { get; } = new List<string>();
+
+        public override void Visit(IOpenApiSchema openApiSchema)
+        {
+            Locations.Add(this.PathString);
+        }
+        public override void Visit(OpenApiComponents components)
+        {
+            Enter("schemas");
+            if (components.Schemas != null)
+            {
+                foreach (var schemaKvp in components.Schemas)
+                {
+                    Enter(schemaKvp.Key);
+                    this.Visit(schemaKvp.Value);
+                    Exit();
+                }
+            }
+            Exit();
+        }
+        public override void Visit(OpenApiDocument doc)
+        {
+            Enter("components");
+            Visit(doc.Components);
+            Exit();
+        }
+    }
+}

test/Microsoft.OpenApi.Tests/Validations/OpenApiRecommendedRulesTests.cs

@@ -200,7 +200,7 @@ public static void GetOperationWithRequestBodyIsInvalid()
         Assert.NotNull(warnings);
         var warning = Assert.Single(warnings);
         Assert.Equal("GET operations should not have a request body.", warning.Message);
-        Assert.Equal("#/paths//people/get/requestBody", warning.Pointer);
+        Assert.Equal("#/paths/~1people/get/requestBody", warning.Pointer);
     }
 
     [Fact]