Add StringSyntaxAttribute.Json

src/libraries/System.Private.CoreLib/src/System/Diagnostics/CodeAnalysis/StringSyntaxAttribute.cs

@@ -40,6 +40,9 @@ public StringSyntaxAttribute(string syntax, params object?[] arguments)
         /// <summary>The syntax identifier for strings containing date and time format specifiers.</summary>
         public const string DateTimeFormat = nameof(DateTimeFormat);
 
+        /// <summary>The syntax identifier for strings containing JavaScript Object Notation (JSON).</summary>
+        public const string Json = nameof(Json);
+
         /// <summary>The syntax identifier for strings containing regular expressions.</summary>
         public const string Regex = nameof(Regex);
     }

src/libraries/System.Runtime/ref/System.Runtime.cs

@@ -9187,6 +9187,7 @@ public StringSyntaxAttribute(string syntax, params object?[] arguments) { }
         public string Syntax { get { throw null; } }
         public object?[] Arguments { get { throw null; } }
         public const string DateTimeFormat = "DateTimeFormat";
+        public const string Json = "Json";
         public const string Regex = "Regex";
     }
     [System.AttributeUsageAttribute(System.AttributeTargets.All, Inherited=false, AllowMultiple=true)]

src/libraries/System.Runtime/tests/System/Diagnostics/CodeAnalysis/StringSyntaxAttributeTests.cs

@@ -9,6 +9,7 @@ public sealed class StringSyntaxAttributeTests
     {
         [Theory]
         [InlineData(StringSyntaxAttribute.DateTimeFormat)]
+        [InlineData(StringSyntaxAttribute.Json)]
         [InlineData(StringSyntaxAttribute.Regex)]
         public void Ctor_Roundtrips(string syntax)
         {

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

@@ -20,8 +20,8 @@ public void Dispose() { }
         public static System.Text.Json.JsonDocument Parse(System.Buffers.ReadOnlySequence<byte> utf8Json, System.Text.Json.JsonDocumentOptions options = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
         public static System.Text.Json.JsonDocument Parse(System.IO.Stream utf8Json, System.Text.Json.JsonDocumentOptions options = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
         public static System.Text.Json.JsonDocument Parse(System.ReadOnlyMemory<byte> utf8Json, System.Text.Json.JsonDocumentOptions options = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
-        public static System.Text.Json.JsonDocument Parse(System.ReadOnlyMemory<char> json, System.Text.Json.JsonDocumentOptions options = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
-        public static System.Text.Json.JsonDocument Parse(string json, System.Text.Json.JsonDocumentOptions options = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
+        public static System.Text.Json.JsonDocument Parse([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] System.ReadOnlyMemory<char> json, System.Text.Json.JsonDocumentOptions options = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
+        public static System.Text.Json.JsonDocument Parse([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] string json, System.Text.Json.JsonDocumentOptions options = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
         public static System.Threading.Tasks.Task<System.Text.Json.JsonDocument> ParseAsync(System.IO.Stream utf8Json, System.Text.Json.JsonDocumentOptions options = default(System.Text.Json.JsonDocumentOptions), System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
         public static System.Text.Json.JsonDocument ParseValue(ref System.Text.Json.Utf8JsonReader reader) { throw null; }
         public static bool TryParseValue(ref System.Text.Json.Utf8JsonReader reader, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out System.Text.Json.JsonDocument? document) { throw null; }
@@ -193,11 +193,11 @@ public static partial class JsonSerializer
         public static object? Deserialize(System.ReadOnlySpan<byte> utf8Json, System.Type returnType, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
         public static object? Deserialize(System.ReadOnlySpan<byte> utf8Json, System.Type returnType, System.Text.Json.Serialization.JsonSerializerContext context) { throw null; }
         [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("JSON serialization and deserialization might require types that cannot be statically analyzed. Use the overload that takes a JsonTypeInfo or JsonSerializerContext, or make sure all of the required types are preserved.")]
-        public static object? Deserialize(System.ReadOnlySpan<char> json, System.Type returnType, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
-        public static object? Deserialize(System.ReadOnlySpan<char> json, System.Type returnType, System.Text.Json.Serialization.JsonSerializerContext context) { throw null; }
+        public static object? Deserialize([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] System.ReadOnlySpan<char> json, System.Type returnType, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
+        public static object? Deserialize([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] System.ReadOnlySpan<char> json, System.Type returnType, System.Text.Json.Serialization.JsonSerializerContext context) { throw null; }
         [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("JSON serialization and deserialization might require types that cannot be statically analyzed. Use the overload that takes a JsonTypeInfo or JsonSerializerContext, or make sure all of the required types are preserved.")]
-        public static object? Deserialize(string json, System.Type returnType, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
-        public static object? Deserialize(string json, System.Type returnType, System.Text.Json.Serialization.JsonSerializerContext context) { throw null; }
+        public static object? Deserialize([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] string json, System.Type returnType, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
+        public static object? Deserialize([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] string json, System.Type returnType, System.Text.Json.Serialization.JsonSerializerContext context) { throw null; }
         [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("JSON serialization and deserialization might require types that cannot be statically analyzed. Use the overload that takes a JsonTypeInfo or JsonSerializerContext, or make sure all of the required types are preserved.")]
         public static object? Deserialize(this System.Text.Json.JsonDocument document, System.Type returnType, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
         public static object? Deserialize(this System.Text.Json.JsonDocument document, System.Type returnType, System.Text.Json.Serialization.JsonSerializerContext context) { throw null; }
@@ -225,11 +225,11 @@ public static partial class JsonSerializer
         public static TValue? Deserialize<TValue>(System.ReadOnlySpan<byte> utf8Json, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
         public static TValue? Deserialize<TValue>(System.ReadOnlySpan<byte> utf8Json, System.Text.Json.Serialization.Metadata.JsonTypeInfo<TValue> jsonTypeInfo) { throw null; }
         [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("JSON serialization and deserialization might require types that cannot be statically analyzed. Use the overload that takes a JsonTypeInfo or JsonSerializerContext, or make sure all of the required types are preserved.")]
-        public static TValue? Deserialize<TValue>(System.ReadOnlySpan<char> json, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
-        public static TValue? Deserialize<TValue>(System.ReadOnlySpan<char> json, System.Text.Json.Serialization.Metadata.JsonTypeInfo<TValue> jsonTypeInfo) { throw null; }
+        public static TValue? Deserialize<TValue>([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] System.ReadOnlySpan<char> json, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
+        public static TValue? Deserialize<TValue>([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] System.ReadOnlySpan<char> json, System.Text.Json.Serialization.Metadata.JsonTypeInfo<TValue> jsonTypeInfo) { throw null; }
         [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("JSON serialization and deserialization might require types that cannot be statically analyzed. Use the overload that takes a JsonTypeInfo or JsonSerializerContext, or make sure all of the required types are preserved.")]
-        public static TValue? Deserialize<TValue>(string json, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
-        public static TValue? Deserialize<TValue>(string json, System.Text.Json.Serialization.Metadata.JsonTypeInfo<TValue> jsonTypeInfo) { throw null; }
+        public static TValue? Deserialize<TValue>([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] string json, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
+        public static TValue? Deserialize<TValue>([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] string json, System.Text.Json.Serialization.Metadata.JsonTypeInfo<TValue> jsonTypeInfo) { throw null; }
         [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("JSON serialization and deserialization might require types that cannot be statically analyzed. Use the overload that takes a JsonTypeInfo or JsonSerializerContext, or make sure all of the required types are preserved.")]
         public static TValue? Deserialize<TValue>(this System.Text.Json.JsonDocument document, System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
         public static TValue? Deserialize<TValue>(this System.Text.Json.JsonDocument document, System.Text.Json.Serialization.Metadata.JsonTypeInfo<TValue> jsonTypeInfo) { throw null; }
@@ -511,9 +511,9 @@ public void WritePropertyName(System.ReadOnlySpan<byte> utf8PropertyName) { }
         public void WritePropertyName(System.ReadOnlySpan<char> propertyName) { }
         public void WritePropertyName(string propertyName) { }
         public void WritePropertyName(System.Text.Json.JsonEncodedText propertyName) { }
-        public void WriteRawValue(string json, bool skipInputValidation = false) { }
+        public void WriteRawValue([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] string json, bool skipInputValidation = false) { }
         public void WriteRawValue(System.ReadOnlySpan<byte> utf8Json, bool skipInputValidation = false) { }
-        public void WriteRawValue(System.ReadOnlySpan<char> json, bool skipInputValidation = false) { }
+        public void WriteRawValue([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] System.ReadOnlySpan<char> json, bool skipInputValidation = false) { }
         public void WriteStartArray() { }
         public void WriteStartArray(System.ReadOnlySpan<byte> utf8PropertyName) { }
         public void WriteStartArray(System.ReadOnlySpan<char> propertyName) { }
@@ -682,7 +682,7 @@ internal JsonNode() { }
         public static implicit operator System.Text.Json.Nodes.JsonNode (ulong value) { throw null; }
         public static System.Text.Json.Nodes.JsonNode? Parse(System.IO.Stream utf8Json, System.Text.Json.Nodes.JsonNodeOptions? nodeOptions = default(System.Text.Json.Nodes.JsonNodeOptions?), System.Text.Json.JsonDocumentOptions documentOptions = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
         public static System.Text.Json.Nodes.JsonNode? Parse(System.ReadOnlySpan<byte> utf8Json, System.Text.Json.Nodes.JsonNodeOptions? nodeOptions = default(System.Text.Json.Nodes.JsonNodeOptions?), System.Text.Json.JsonDocumentOptions documentOptions = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
-        public static System.Text.Json.Nodes.JsonNode? Parse(string json, System.Text.Json.Nodes.JsonNodeOptions? nodeOptions = default(System.Text.Json.Nodes.JsonNodeOptions?), System.Text.Json.JsonDocumentOptions documentOptions = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
+        public static System.Text.Json.Nodes.JsonNode? Parse([System.Diagnostics.CodeAnalysis.StringSyntaxAttribute(System.Diagnostics.CodeAnalysis.StringSyntaxAttribute.Json)] string json, System.Text.Json.Nodes.JsonNodeOptions? nodeOptions = default(System.Text.Json.Nodes.JsonNodeOptions?), System.Text.Json.JsonDocumentOptions documentOptions = default(System.Text.Json.JsonDocumentOptions)) { throw null; }
         public static System.Text.Json.Nodes.JsonNode? Parse(ref System.Text.Json.Utf8JsonReader reader, System.Text.Json.Nodes.JsonNodeOptions? nodeOptions = default(System.Text.Json.Nodes.JsonNodeOptions?)) { throw null; }
         public string ToJsonString(System.Text.Json.JsonSerializerOptions? options = null) { throw null; }
         public override string ToString() { throw null; }

src/libraries/System.Text.Json/ref/System.Text.Json.csproj

@@ -20,6 +20,10 @@
     <Compile Include="$(CoreLibSharedDir)System\Diagnostics\CodeAnalysis\RequiresUnreferencedCodeAttribute.cs" />
   </ItemGroup>
 
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">
+    <Compile Include="$(CoreLibSharedDir)System\Diagnostics\CodeAnalysis\StringSyntaxAttribute.cs" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="$(LibrariesProjectRoot)System.Text.Encodings.Web\ref\System.Text.Encodings.Web.csproj" />
   </ItemGroup>

src/libraries/System.Text.Json/src/System.Text.Json.csproj

@@ -322,6 +322,9 @@ System.Text.Json.Nodes.JsonValue</PackageDescription>
     <!-- Common or Common-branched source files -->
     <Compile Include="$(CommonPath)System\Buffers\ArrayBufferWriter.cs" Link="Common\System\Buffers\ArrayBufferWriter.cs" />
   </ItemGroup>
+  <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net7.0'))">
+    <Compile Include="$(CoreLibSharedDir)System\Diagnostics\CodeAnalysis\StringSyntaxAttribute.cs" />
+  </ItemGroup>
   <!-- Application tfms (.NETCoreApp, .NETFramework) need to use the same or higher version of .NETStandard's dependencies. -->
   <ItemGroup>
     <ProjectReference Include="$(LibrariesProjectRoot)System.Runtime.CompilerServices.Unsafe\src\System.Runtime.CompilerServices.Unsafe.ilproj" />

src/libraries/System.Text.Json/src/System/Text/Json/Document/JsonDocument.Parse.cs

@@ -247,7 +247,7 @@ private static async Task<JsonDocument> ParseAsyncCore(
         /// <exception cref="ArgumentException">
         ///   <paramref name="options"/> contains unsupported options.
         /// </exception>
-        public static JsonDocument Parse(ReadOnlyMemory<char> json, JsonDocumentOptions options = default)
+        public static JsonDocument Parse([StringSyntax(StringSyntaxAttribute.Json)] ReadOnlyMemory<char> json, JsonDocumentOptions options = default)
         {
             ReadOnlySpan<char> jsonChars = json.Span;
             int expectedByteCount = JsonReaderHelper.GetUtf8ByteCount(jsonChars);
@@ -311,7 +311,7 @@ internal static JsonDocument ParseValue(ReadOnlyMemory<char> json, JsonDocumentO
         /// <exception cref="ArgumentException">
         ///   <paramref name="options"/> contains unsupported options.
         /// </exception>
-        public static JsonDocument Parse(string json, JsonDocumentOptions options = default)
+        public static JsonDocument Parse([StringSyntax(StringSyntaxAttribute.Json)] string json, JsonDocumentOptions options = default)
         {
             if (json == null)
             {

src/libraries/System.Text.Json/src/System/Text/Json/Nodes/JsonNode.Parse.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Text.Json.Serialization.Converters;
 
@@ -65,7 +66,7 @@ public abstract partial class JsonNode
         ///   <paramref name="json"/> does not represent a valid single JSON value.
         /// </exception>
         public static JsonNode? Parse(
-            string json,
+            [StringSyntax(StringSyntaxAttribute.Json)] string json,
             JsonNodeOptions? nodeOptions = null,
             JsonDocumentOptions documentOptions = default(JsonDocumentOptions))
         {