Json serializer type discovery (dotnet#18)

* Create JsonSerializableAttribute attribute for type discovery

* Include reflection utils and implement basic type discovery

* Update unit tests for TypeDiscovery

* Use linq for cleaner JsonSerializationSyntaxReceiver

* Update license for reflection utils

* Update tests and generator to latest model

* Add external class unit tests for Type Discovery

* Update summary, variable names and other nits

* Update csharp coding style applied to vars

* Separated Unit Tests into helper classes and minor changes for nullables in Syntax Receiver

* Create test cases checking full type wrapper in end to end and change typewrapper to show private methods

* Update dicitonary to list for syntax receiver

* Separate syntax receiver to new file

Author: kevinwkt

src/libraries/System.Text.Json/System.Text.Json.SourceGeneration.Tests/JsonSourceGeneratorTests.cs

@@ -2,16 +2,90 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
 using Xunit;
 
 namespace System.Text.Json.SourceGeneration.Tests
 {
-    public class JsonSerializerSouceGeneratorTests
+    public class JsonSerializerSourceGeneratorTests
     {
+        [JsonSerializable]
+        public class SampleInternalTest
+        {
+            public char PublicCharField;
+            private string PrivateStringField;
+            public int PublicIntPropertyPublic { get; set; }
+            public int PublicIntPropertyPrivateSet { get; private set; }
+            public int PublicIntPropertyPrivateGet { private get; set; }
+
+            public SampleInternalTest()
+            {
+                PublicCharField = 'a';
+                PrivateStringField = "privateStringField";
+            }
+
+            public SampleInternalTest(char c, string s)
+            {
+                PublicCharField = c;
+                PrivateStringField = s;
+            }
+
+            private SampleInternalTest(int i)
+            {
+                PublicIntPropertyPublic = i;
+            }
+
+            private void UseFields()
+            {
+                string use = PublicCharField.ToString() + PrivateStringField;
+            }
+        }
+
+        [JsonSerializable(typeof(JsonConverterAttribute))]
+        public class SampleExternalTest { }
+
         [Fact]
-        public static void TestGeneratedCode()
+        public void TestGeneratedCode()
         {
-            Assert.Equal("Hello", HelloWorldGenerated.HelloWorld.SayHello());
+            var internalTypeTest = new HelloWorldGenerated.SampleInternalTestClassInfo();
+            var externalTypeTest = new HelloWorldGenerated.SampleExternalTestClassInfo();
+
+            // Check base class names.
+            Assert.Equal("SampleInternalTestClassInfo", internalTypeTest.GetClassName());
+            Assert.Equal("SampleExternalTestClassInfo", externalTypeTest.GetClassName());
+
+            // Public and private Ctors are visible.
+            Assert.Equal(3, internalTypeTest.Ctors.Count);
+            Assert.Equal(2, externalTypeTest.Ctors.Count);
+
+            // Ctor params along with its types are visible.
+            Dictionary<string, string> expectedCtorParamsInternal = new Dictionary<string, string> { { "c", "Char"}, { "s", "String" }, { "i", "Int32" } };
+            Assert.Equal(expectedCtorParamsInternal, internalTypeTest.CtorParams);
+
+            Dictionary<string, string> expectedCtorParamsExternal = new Dictionary<string, string> { { "converterType", "Type"} };
+            Assert.Equal(expectedCtorParamsExternal, externalTypeTest.CtorParams);
+
+            // Public and private methods are visible.
+            List<string> expectedMethodsInternal = new List<string> { "get_PublicIntPropertyPublic", "set_PublicIntPropertyPublic", "get_PublicIntPropertyPrivateSet", "set_PublicIntPropertyPrivateSet", "get_PublicIntPropertyPrivateGet", "set_PublicIntPropertyPrivateGet", "UseFields" };
+            Assert.Equal(expectedMethodsInternal, internalTypeTest.Methods);
+
+            List<string> expectedMethodsExternal = new List<string> { "get_ConverterType", "CreateConverter" };
+            Assert.Equal(expectedMethodsExternal, externalTypeTest.Methods);
+
+            // Public and private fields are visible.
+            Dictionary<string, string> expectedFieldsInternal = new Dictionary<string, string> { { "PublicCharField", "Char" }, { "PrivateStringField", "String" } };
+            Assert.Equal(expectedFieldsInternal, internalTypeTest.Fields);
+
+            Dictionary<string, string> expectedFieldsExternal = new Dictionary<string, string> { };
+            Assert.Equal(expectedFieldsExternal, externalTypeTest.Fields);
+
+            // Public properties are visible.
+            Dictionary<string, string> expectedPropertiesInternal = new Dictionary<string, string> { { "PublicIntPropertyPublic", "Int32" }, { "PublicIntPropertyPrivateSet", "Int32" }, { "PublicIntPropertyPrivateGet", "Int32" } };
+            Assert.Equal(expectedPropertiesInternal, internalTypeTest.Properties);
+
+            Dictionary<string, string> expectedPropertiesExternal = new Dictionary<string, string> { { "ConverterType", "Type"} };
+            Assert.Equal(expectedPropertiesExternal, externalTypeTest.Properties);
         }
     }
 }

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

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetFrameworkCurrent)</TargetFrameworks>
   </PropertyGroup>

src/libraries/System.Text.Json/System.Text.Json.SourceGeneration.UnitTests/JsonSourceGeneratorTests.cs

@@ -2,32 +2,181 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Reflection;
+using System.Text.Json.Serialization;
 using Microsoft.CodeAnalysis;
-using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.CSharp;
 using Xunit;
 
 namespace System.Text.Json.SourceGeneration.UnitTests
 {
-    public static class GeneratorTests
+    public class GeneratorTests
     {
         [Fact]
-        public static void SourceGeneratorInitializationPass()
+        public void TypeDiscoveryPrimitivePOCO()
         {
+            string source = @"
+            using System;
+            using System.Text.Json.Serialization;
+
+              namespace HelloWorld
+              {
+                [JsonSerializable]
+                public class MyType {
+                    public int PublicPropertyInt { get; set; }
+                    public string PublicPropertyString { get; set; }
+                    private int PrivatePropertyInt { get; set; }
+                    private string PrivatePropertyString { get; set; }
+
+                    public double PublicDouble;
+                    public char PublicChar;
+                    private double PrivateDouble;
+                    private char PrivateChar;
+
+                    public void MyMethod() { }
+                    public void MySecondMethod() { }
+                }
+              }";
+
+            Compilation compilation = CreateCompilation(source);
+
+            JsonSerializerSourceGenerator generator = new JsonSerializerSourceGenerator();
+
+            Compilation outCompilation = RunGenerators(compilation, out var generatorDiags, generator);
+
+            // Check base functionality of found types.
+            Assert.Equal(1, generator.foundTypes.Count);
+            Assert.Equal("HelloWorld.MyType", generator.foundTypes["MyType"].FullName);
+
+            // Check for received properties in created type.
+            string[] expectedPropertyNames = { "PublicPropertyInt", "PublicPropertyString", "PrivatePropertyInt", "PrivatePropertyString" };
+            string[] receivedPropertyNames = generator.foundTypes["MyType"].GetProperties().Select(property => property.Name).ToArray();
+            Assert.Equal(expectedPropertyNames, receivedPropertyNames);
+
+            // Check for fields in created type.
+            string[] expectedFieldNames = { "PublicDouble", "PublicChar", "PrivateDouble", "PrivateChar" };
+            string[] receivedFieldNames = generator.foundTypes["MyType"].GetFields().Select(field => field.Name).ToArray();
+            Assert.Equal(expectedFieldNames, receivedFieldNames);
+
+            // Check for methods in created type.
+            string[] expectedMethodNames = { "get_PublicPropertyInt", "set_PublicPropertyInt", "get_PublicPropertyString", "set_PublicPropertyString", "get_PrivatePropertyInt", "set_PrivatePropertyInt", "get_PrivatePropertyString", "set_PrivatePropertyString", "MyMethod", "MySecondMethod" };
+            string[] receivedMethodNames = generator.foundTypes["MyType"].GetMethods().Select(method => method.Name).ToArray();
+            Assert.Equal(expectedMethodNames, receivedMethodNames);
         }
 
         [Fact]
-        public static void SourceGeneratorInitializationFail()
+        public void TypeDiscoveryPrimitiveTemporaryPOCO()
         {
+            string source = @"
+            using System;
+            using System.Text.Json.Serialization;
+
+              namespace HelloWorld
+              {
+                [JsonSerializable]
+                public class MyType {
+                    public int PublicPropertyInt { get; set; }
+                    public string PublicPropertyString { get; set; }
+                    private int PrivatePropertyInt { get; set; }
+                    private string PrivatePropertyString { get; set; }
+
+                    public double PublicDouble;
+                    public char PublicChar;
+                    private double PrivateDouble;
+                    private char PrivateChar;
+
+                    public void MyMethod() { }
+                    public void MySecondMethod() { }
+                }
+
+                [JsonSerializable(typeof(JsonConverterAttribute))]
+                public class NotMyType { }
+
+              }";
+
+            Compilation compilation = CreateCompilation(source);
+
+            JsonSerializerSourceGenerator generator = new JsonSerializerSourceGenerator();
+
+            Compilation outCompilation = RunGenerators(compilation, out var generatorDiags, generator);
+
+            // Check base functionality of found types.
+            Assert.Equal(2, generator.foundTypes.Count);
+
+            // Check for MyType.
+            Assert.Equal("HelloWorld.MyType", generator.foundTypes["MyType"].FullName);
+
+            // Check for received properties in created type.
+            string[] expectedPropertyNamesMyType = { "PublicPropertyInt", "PublicPropertyString", "PrivatePropertyInt", "PrivatePropertyString" };
+            string[] receivedPropertyNamesMyType = generator.foundTypes["MyType"].GetProperties().Select(property => property.Name).ToArray();
+            Assert.Equal(expectedPropertyNamesMyType, receivedPropertyNamesMyType);
+
+            // Check for fields in created type.
+            string[] expectedFieldNamesMyType = { "PublicDouble", "PublicChar", "PrivateDouble", "PrivateChar" };
+            string[] receivedFieldNamesMyType = generator.foundTypes["MyType"].GetFields().Select(field => field.Name).ToArray();
+            Assert.Equal(expectedFieldNamesMyType, receivedFieldNamesMyType);
+
+            // Check for methods in created type.
+            string[] expectedMethodNamesMyType = { "get_PublicPropertyInt", "set_PublicPropertyInt", "get_PublicPropertyString", "set_PublicPropertyString", "get_PrivatePropertyInt", "set_PrivatePropertyInt", "get_PrivatePropertyString", "set_PrivatePropertyString", "MyMethod", "MySecondMethod" };
+            string[] receivedMethodNamesMyType = generator.foundTypes["MyType"].GetMethods().Select(method => method.Name).ToArray();
+            Assert.Equal(expectedMethodNamesMyType, receivedMethodNamesMyType);
+
+            // Check for NotMyType.
+            Assert.Equal("System.Text.Json.Serialization.JsonConverterAttribute", generator.foundTypes["NotMyType"].FullName);
+
+            // Check for received properties in created type.
+            string[] expectedPropertyNamesNotMyType = { "ConverterType" };
+            string[] receivedPropertyNamesNotMyType = generator.foundTypes["NotMyType"].GetProperties().Select(property => property.Name).ToArray();
+            Assert.Equal(expectedPropertyNamesNotMyType, receivedPropertyNamesNotMyType);
+
+            // Check for fields in created type.
+            string[] expectedFieldNamesNotMyType = { };
+            string[] receivedFieldNamesNotMyType = generator.foundTypes["NotMyType"].GetFields().Select(field => field.Name).ToArray();
+            Assert.Equal(expectedFieldNamesNotMyType, receivedFieldNamesNotMyType);
+
+            // Check for methods in created type.
+            string[] expectedMethodNamesNotMyType = { "get_ConverterType", "CreateConverter" };
+            string[] receivedMethodNamesNotMyType = generator.foundTypes["NotMyType"].GetMethods().Select(method => method.Name).ToArray();
+            Assert.Equal(expectedMethodNamesNotMyType, receivedMethodNamesNotMyType);
         }
 
-        [Fact]
-        public static void SourceGeneratorExecutionPass()
+        private Compilation CreateCompilation(string source)
         {
+            // Bypass System.Runtime error.
+            Assembly systemRuntimeAssembly = Assembly.Load("System.Runtime, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a");
+            string systemRuntimeAssemblyPath = systemRuntimeAssembly.Location;
+
+            MetadataReference[] references = new MetadataReference[] {
+                MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
+                MetadataReference.CreateFromFile(typeof(Attribute).Assembly.Location),
+                MetadataReference.CreateFromFile(typeof(JsonSerializableAttribute).Assembly.Location),
+                MetadataReference.CreateFromFile(typeof(JsonSerializerOptions).Assembly.Location),
+                MetadataReference.CreateFromFile(typeof(Type).Assembly.Location),
+                MetadataReference.CreateFromFile(typeof(KeyValuePair).Assembly.Location),
+                MetadataReference.CreateFromFile(systemRuntimeAssemblyPath),
+            };
+
+            return CSharpCompilation.Create(
+                "TestAssembly",
+                syntaxTrees: new[] { CSharpSyntaxTree.ParseText(source) },
+                references: references,
+                options: new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary)
+            );
         }
 
-        [Fact]
-        public static void SourceGeneratorExecutionFail()
+        private GeneratorDriver CreateDriver(Compilation compilation, params ISourceGenerator[] generators)
+            => new CSharpGeneratorDriver(
+                 new CSharpParseOptions(kind: SourceCodeKind.Regular, documentationMode: DocumentationMode.Parse),
+                ImmutableArray.Create(generators),
+                ImmutableArray<AdditionalText>.Empty);
+
+        private Compilation RunGenerators(Compilation compilation, out ImmutableArray<Diagnostic> diagnostics, params ISourceGenerator[] generators)
         {
+            CreateDriver(compilation, generators).RunFullGeneration(compilation, out Compilation outCompilation, out diagnostics);
+            return outCompilation;
         }
     }
 }

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

@@ -5,6 +5,8 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis" Version="$(MicrosoftCodeAnalysisVersion)" PrivateAssets="all" />
+
+    <ProjectReference Include="..\src\System.Text.Json.csproj" />
     <ProjectReference Include="..\System.Text.Json.SourceGeneration\System.Text.Json.SourceGeneration.csproj" />
   </ItemGroup>
 

src/libraries/System.Text.Json/System.Text.Json.SourceGeneration/JsonSerializableSyntaxReceiver.cs

@@ -0,0 +1,54 @@
+// 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 System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace System.Text.Json.SourceGeneration
+{
+        public class JsonSerializableSyntaxReceiver : ISyntaxReceiver
+        {
+            public List<KeyValuePair<string, IdentifierNameSyntax>> ExternalClassTypes = new List<KeyValuePair<string, IdentifierNameSyntax>>();
+            public List<KeyValuePair<string, TypeDeclarationSyntax>> InternalClassTypes = new List<KeyValuePair<string, TypeDeclarationSyntax>>();
+
+            public void OnVisitSyntaxNode(SyntaxNode syntaxNode)
+            {
+                // Look for classes or structs for JsonSerializable Attribute.
+                if (syntaxNode is ClassDeclarationSyntax || syntaxNode is StructDeclarationSyntax)
+                {
+                    // Find JsonSerializable Attributes.
+                    IEnumerable<AttributeSyntax>? serializableAttributes = null;
+                    AttributeListSyntax attributeList = ((TypeDeclarationSyntax)syntaxNode).AttributeLists.SingleOrDefault();
+                    if (attributeList != null)
+                    {
+                        serializableAttributes = attributeList.Attributes.Where(node => (node is AttributeSyntax attr && attr.Name.ToString() == "JsonSerializable")).Cast<AttributeSyntax>();
+                    }
+
+                    if (serializableAttributes?.Any() == true)
+                    {
+                        // JsonSerializableAttribute has AllowMultiple as False, should only have 1 attribute.
+                        Debug.Assert(serializableAttributes.Count() == 1);
+                        AttributeSyntax attributeNode = serializableAttributes.First();
+
+                        // Check if the attribute is being passed a type.
+                        if (attributeNode.DescendantNodes().Where(node => node is TypeOfExpressionSyntax).Any())
+                        {
+                            // Get JsonSerializable attribute arguments.
+                            AttributeArgumentSyntax attributeArgumentNode = (AttributeArgumentSyntax)attributeNode.DescendantNodes().Where(node => node is AttributeArgumentSyntax).SingleOrDefault();
+                            // Get external class token from arguments.
+                            IdentifierNameSyntax externalTypeNode = (IdentifierNameSyntax)attributeArgumentNode?.DescendantNodes().Where(node => node is IdentifierNameSyntax).SingleOrDefault();
+                            ExternalClassTypes.Add(new KeyValuePair<string, IdentifierNameSyntax>(((TypeDeclarationSyntax)syntaxNode).Identifier.Text, externalTypeNode));
+                        }
+                        else
+                        {
+                            InternalClassTypes.Add(new KeyValuePair<string, TypeDeclarationSyntax>(((TypeDeclarationSyntax)syntaxNode).Identifier.Text, (TypeDeclarationSyntax)syntaxNode));
+                        }
+                    }
+                }
+            }
+        }
+}