Json prototype - transformation API (#2)

* transformation API added
* assertions to existing scenarios added

src/System.Text.Json/ref/System.Text.Json.cs

@@ -84,6 +84,7 @@ public void Insert(int index, ushort item) { }
         public void Insert(int index, uint item) { }
         [System.CLSCompliantAttribute(false)]
         public void Insert(int index, ulong item) { }
+        public int LastIndexOf(System.Text.Json.JsonNode item) { throw null; }
         public bool Remove(System.Text.Json.JsonNode item) { throw null; }
         public void RemoveAt(int index) { }
         void System.Collections.Generic.ICollection<System.Text.Json.JsonNode>.CopyTo(System.Text.Json.JsonNode[] array, int arrayIndex) { }
@@ -130,6 +131,7 @@ public readonly partial struct JsonElement
     {
         private readonly object _dummy;
         private readonly int _dummyPrimitive;
+        public bool IsImmutable { get { throw null; } }
         public System.Text.Json.JsonElement this[int index] { get { throw null; } }
         public System.Text.Json.JsonValueKind ValueKind { get { throw null; } }
         public System.Text.Json.JsonElement Clone() { throw null; }
@@ -247,9 +249,20 @@ protected JsonNamingPolicy() { }
         public static System.Text.Json.JsonNamingPolicy CamelCase { get { throw null; } }
         public abstract string ConvertName(string name);
     }
-    public partial class JsonNode
-    {
-        public JsonNode() { }
+    public abstract partial class JsonNode
+    {
+        internal JsonNode() { }
+        public System.Text.Json.JsonElement AsJsonElement() { throw null; }
+        public static System.Text.Json.JsonNode DeepCopy(System.Text.Json.JsonDocument jsonDocument) { throw null; }
+        public static System.Text.Json.JsonNode DeepCopy(System.Text.Json.JsonElement jsonElement) { throw null; }
+        public static System.Text.Json.JsonNode DeepCopy(System.Text.Json.JsonNode jsonNode) { throw null; }
+        public static System.Text.Json.JsonNode GetNode(System.Text.Json.JsonElement jsonElement) { throw null; }
+        public static System.Text.Json.JsonNode Parse(System.Buffers.ReadOnlySequence<byte> utf8Json) { throw null; }
+        public static System.Text.Json.JsonNode Parse(System.IO.Stream utf8Json) { throw null; }
+        public static System.Text.Json.JsonNode Parse(System.ReadOnlyMemory<byte> utf8Json) { throw null; }
+        public static System.Text.Json.JsonNode Parse(System.ReadOnlyMemory<char> json) { throw null; }
+        public static System.Text.Json.JsonNode Parse(string json) { throw null; }
+        public static bool TryGetNode(System.Text.Json.JsonElement jsonElement, out System.Text.Json.JsonNode jsonNode) { throw null; }
     }
     public partial class JsonNumber : System.Text.Json.JsonNode
     {
@@ -360,9 +373,9 @@ public void Add(string propertyName, ulong propertyValue) { }
         public void AddRange(System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<string, System.Text.Json.JsonNode>> jsonProperties) { }
         public bool ContainsProperty(string propertyName) { throw null; }
         public System.Collections.Generic.IEnumerable<System.Text.Json.JsonNode> GetAllProperties(string propertyName) { throw null; }
-        public System.Text.Json.JsonArray GetArrayProperty(string propertyName) { throw null; }
         public System.Collections.Generic.IEnumerator<System.Collections.Generic.KeyValuePair<string, System.Text.Json.JsonNode>> GetEnumerator() { throw null; }
-        public System.Text.Json.JsonObject GetObjectProperty(string propertyName) { throw null; }
+        public System.Text.Json.JsonArray GetJsonArrayProperty(string propertyName) { throw null; }
+        public System.Text.Json.JsonObject GetJsonObjectProperty(string propertyName) { throw null; }
         public System.Text.Json.JsonNode GetProperty(string propertyName) { throw null; }
         public bool ModifyPropertyName(string oldName, string newName) { throw null; }
         public bool Remove(string propertyName) { throw null; }

src/System.Text.Json/src/System/Text/Json/Document/JsonElement.cs

@@ -1440,5 +1440,10 @@ private void CheckValidInstance()
 
         [DebuggerBrowsable(DebuggerBrowsableState.Never)]
         private string DebuggerDisplay => $"ValueKind = {ValueKind} : \"{ToString()}\"";
+
+// for now disabling error caused by not adding documentation to methods 
+#pragma warning disable CS1591
+        public bool IsImmutable => throw null;
+#pragma warning restore CS1591
     }
 }

src/System.Text.Json/src/System/Text/Json/Node/JsonArray.cs

@@ -87,10 +87,11 @@ public void Add(ulong value) { }
         [CLSCompliant(false)]
         public bool Contains(ulong value) { throw null; }
 
-        public int Count => throw new NotImplementedException();
-        public bool IsReadOnly => throw new NotImplementedException();
+        public int Count => throw null;
+        public bool IsReadOnly => throw null;
 
         public int IndexOf(JsonNode item) { throw null; }
+        public int LastIndexOf(JsonNode item) { throw null; }
         public void RemoveAt(int index) { throw null; }
         public void Clear() { throw null; }
         public bool Remove(JsonNode item) { throw null; }

src/System.Text.Json/src/System/Text/Json/Node/JsonNode.cs

@@ -5,11 +5,29 @@
 // for now disabling error caused by not adding documentation to methods 
 #pragma warning disable CS1591
 
+using System.Buffers;
+using System.IO;
+
 namespace System.Text.Json
 {
-    public partial class JsonNode
+    public abstract partial class JsonNode
     {
+        private protected JsonNode() { }
+        public JsonElement AsJsonElement() { throw null; }
+
+        public static JsonNode GetNode(JsonElement jsonElement) { throw null; }
+        public static bool TryGetNode(JsonElement jsonElement, out JsonNode jsonNode) { throw null; }
+
+        public static JsonNode Parse(string json) { throw null; }
+        public static JsonNode Parse(ReadOnlySequence<byte> utf8Json) { throw null; }
+        public static JsonNode Parse(Stream utf8Json) { throw null; }
+        public static JsonNode Parse(ReadOnlyMemory<byte> utf8Json) { throw null; }
+        public static JsonNode Parse(ReadOnlyMemory<char> json) { throw null; }
+
 
+        public static JsonNode DeepCopy(JsonNode jsonNode) { throw null; }
+        public static JsonNode DeepCopy(JsonElement jsonElement) { throw null; }
+        public static JsonNode DeepCopy(JsonDocument jsonDocument) { throw null; }
     }
 }
 

src/System.Text.Json/src/System/Text/Json/Node/JsonObject.cs

@@ -47,9 +47,9 @@ public void AddRange(IEnumerable<KeyValuePair<string, JsonNode>> jsonProperties)
 
         public JsonNode GetProperty(string propertyName) { throw null; }
         public bool TryGetProperty(string propertyName, out JsonNode jsonNode) { throw null; }
-        public JsonObject GetObjectProperty(string propertyName) { throw null; }
+        public JsonObject GetJsonObjectProperty(string propertyName) { throw null; }
         public bool TryGetObjectProperty(string propertyName, out JsonObject jsonObject) { throw null; }
-        public JsonArray GetArrayProperty(string propertyName) { throw null; }
+        public JsonArray GetJsonArrayProperty(string propertyName) { throw null; }
         public bool TryGetArrayProperty(string propertyName, out JsonArray jsonArray) { throw null; }
         public IEnumerable<JsonNode> GetAllProperties(string propertyName) { throw null; }
 

src/System.Text.Json/tests/System.Text.Json.Tests.csproj

@@ -102,7 +102,11 @@
     <Compile Include="Utf8JsonReaderTests.ValueTextEquals.cs" />
     <Compile Include="Utf8JsonWriterTests.cs" />
     <Compile Include="..\src\System\Text\Json\BitStack.cs" Link="BitStack.cs" />
+    <Compile Include="WritableJsonApiTests.TestAccessingNestedMembers.cs" />
+    <Compile Include="WritableJsonApiTests.TestModifying.cs" />
+    <Compile Include="WritableJsonApiTests.TestTransformations.cs" />
     <Compile Include="WritableJsonApiTests.cs" />
+    <Compile Include="WritableJsonApiTests.TestData.cs" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetsNetFx)' == 'true'">
     <Compile Include="$(CommonPath)\System\Buffers\ArrayBufferWriter.cs">

src/System.Text.Json/tests/WritableJsonApiTests.TestAccessingNestedMembers.cs

@@ -0,0 +1,146 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Xunit;
+
+namespace System.Text.Json
+{
+#pragma warning disable xUnit1000
+    internal static partial class WritableJsonApiTests
+#pragma warning enable xUnit1000
+    {
+        /// <summary>
+        /// Accesing nested Json object - casting with as operator
+        /// </summary>
+        [Fact]
+        public static void TestAccesingNestedJsonObjectCastWithAs()
+        {
+            JsonObject manager = EmployeesDatabase.GetManager();
+
+            // Should not throw any exceptions:
+
+            var reportingEmployees = manager["reporting employees"] as JsonObject;
+            if (reportingEmployees == null)
+                throw new InvalidCastException();
+
+            var softwareDevelopers = reportingEmployees["software developers"] as JsonObject;
+            if (softwareDevelopers == null)
+                throw new InvalidCastException();
+
+            var internDevelopers = softwareDevelopers["intern employees"] as JsonObject;
+            if (internDevelopers == null)
+                throw new InvalidCastException();
+
+            internDevelopers.Add(EmployeesDatabase.GetNextEmployee());
+        }
+
+        /// <summary>
+        /// Accesing nested Json object - casting with is operator
+        /// </summary>
+        [Fact]
+        public static void TestAccesingNestedJsonObjectCastWithIs()
+        {
+            JsonObject manager = EmployeesDatabase.GetManager();
+
+            static bool AddEmployee(JsonObject manager)
+            {
+
+                if (manager["reporting employees"] is JsonObject reportingEmployees)
+                {
+                    if (reportingEmployees["software developers"] is JsonObject softwareDevelopers)
+                    {
+                        if (softwareDevelopers["full time employees"] is JsonObject fullTimeEmployees)
+                        {
+                            fullTimeEmployees.Add(EmployeesDatabase.GetNextEmployee());
+                            return true;
+                        }
+                    }
+                }
+                return false;
+            }
+
+            bool success = AddEmployee(manager);
+            Assert.True(success);
+        }
+
+        /// <summary>
+        /// Accesing nested Json object - explicit casting
+        /// </summary>
+        [Fact]
+        public static void TestAccesingNestedJsonObjectExplicitCast()
+        {
+            JsonObject manager = EmployeesDatabase.GetManager();
+
+            // Should not throw any exceptions:
+            ((JsonObject)((JsonObject)manager["reporting employees"])["HR"]).Add(EmployeesDatabase.GetNextEmployee());
+        }
+
+        /// <summary>
+        /// Accesing nested Json object - GetObjectProperty method
+        /// </summary>
+        [Fact]
+        public static void TestAccesingNestedJsonObjectGetPropertyMethod()
+        {
+            JsonObject manager = EmployeesDatabase.GetManager();
+
+            // Should not throw any exceptions:
+
+            JsonObject internDevelopers = manager.GetJsonObjectProperty("reporting employees")
+                                          .GetJsonObjectProperty("software developers")
+                                          .GetJsonObjectProperty("intern employees");
+            internDevelopers.Add(EmployeesDatabase.GetNextEmployee());
+        }
+
+        /// <summary>
+        /// Accesing nested Json object - TryGetObjectProperty method
+        /// </summary>
+        [Fact]
+        public static void TestAccesingNestedJsonObjectTryGetPropertyMethod()
+        {
+            JsonObject manager = EmployeesDatabase.GetManager();
+
+            static bool AddEmployee(JsonObject manager)
+            {
+                if (manager.TryGetObjectProperty("reporting employees", out JsonObject reportingEmployees))
+                {
+                    if (reportingEmployees.TryGetObjectProperty("software developers", out JsonObject softwareDevelopers))
+                    {
+                        if (softwareDevelopers.TryGetObjectProperty("full time employees", out JsonObject fullTimeEmployees))
+                        {
+                            fullTimeEmployees.Add(EmployeesDatabase.GetNextEmployee());
+                            return true;
+                        }
+                    }
+                }
+
+                return false;
+            }
+
+            bool success = AddEmployee(manager);
+            Assert.True(success);
+        }
+
+        /// <summary>
+        /// Accesing nested Json array - GetArrayProperty method
+        /// </summary>
+        [Fact]
+        public static void TestAccesingNestedJsonArrayGetPropertyMethod()
+        {
+            var issues = new JsonObject()
+            {
+                { "features", new JsonArray{ "new functionality 1", "new functionality 2" } },
+                { "bugs", new JsonArray{ "bug 123", "bug 4566", "bug 821" } },
+                { "tests", new JsonArray{ "code coverage" } },
+            };
+
+            issues.GetJsonArrayProperty("bugs").Add("bug 12356");
+            ((JsonString)issues.GetJsonArrayProperty("features")[0]).Value = "feature 1569";
+            ((JsonString)issues.GetJsonArrayProperty("features")[1]).Value = "feature 56134";
+
+            Assert.True(((JsonArray)issues["bugs"]).Contains("bug 12356"));
+            Assert.Equal((JsonString)((JsonArray)issues["features"])[0], "feature 1569");
+            Assert.Equal((JsonString)((JsonArray)issues["features"])[1], "feature 56134");
+        }
+    }
+}