From 117ffb204a8cbdd5c44615a640859cc2bb1f2b71 Mon Sep 17 00:00:00 2001
From: Manuel de la Pena Saenz <mandel@microsoft.com>
Date: Fri, 24 Jan 2025 07:06:14 -0500
Subject: [PATCH] [RGen] Implement the BindAttribute parsing logic for the
 transformer.

---
 .../Attributes/BindData.cs                    | 94 +++++++++++++++++++
 .../Attributes/BindDataTests.cs               | 92 ++++++++++++++++++
 2 files changed, 186 insertions(+)
 create mode 100644 src/rgen/Microsoft.Macios.Transformer/Attributes/BindData.cs
 create mode 100644 tests/rgen/Microsoft.Macios.Transformer.Tests/Attributes/BindDataTests.cs

diff --git a/src/rgen/Microsoft.Macios.Transformer/Attributes/BindData.cs b/src/rgen/Microsoft.Macios.Transformer/Attributes/BindData.cs
new file mode 100644
index 00000000000..e642e3bc2c2
--- /dev/null
+++ b/src/rgen/Microsoft.Macios.Transformer/Attributes/BindData.cs
@@ -0,0 +1,94 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System.Diagnostics.CodeAnalysis;
+using Microsoft.CodeAnalysis;
+
+namespace Microsoft.Macios.Transformer.Attributes;
+
+readonly struct BindData : IEquatable<BindData> {
+	
+	public string Selector { get; }
+	public bool Virtual { get; init; }
+	
+	public BindData (string selector, bool isVirtual = false)
+	{
+		Selector = selector;
+		Virtual = isVirtual;
+	}
+	
+	public static bool TryParse (AttributeData attributeData,
+		[NotNullWhen (true)] out BindData? data)
+	{
+		data = null;
+		var count = attributeData.ConstructorArguments.Length;
+		string selector;
+		bool @virtual = false;
+		// custom marshal directive values
+
+		switch (count) {
+		case 1:
+			selector = (string) attributeData.ConstructorArguments [0].Value!;
+			break;
+		default:
+			// 0 should not be an option..
+			return false;
+		}
+
+		if (attributeData.NamedArguments.Length == 0) {
+			data = new (selector);
+			return true;
+		}
+
+		foreach (var (argumentName, value) in attributeData.NamedArguments) {
+			switch (argumentName) {
+			case "Selector":
+				selector = (string) value.Value!;
+				break;
+			case "Virtual":
+				@virtual = (bool) value.Value!;
+				break;
+			default:
+				data = null;
+				return false;
+			}
+		}
+
+		data = new(selector) { Virtual = @virtual, };
+		return true;
+	}
+	
+	public bool Equals (BindData other)
+	{
+		if (Selector != other.Selector)
+			return false;
+		return Virtual == other.Virtual;
+	}
+
+	/// <inheritdoc />
+	public override bool Equals (object? obj)
+	{
+		return obj is BindData other && Equals (other);
+	}
+
+	/// <inheritdoc />
+	public override int GetHashCode ()
+		=> HashCode.Combine (Selector, Virtual);
+		
+
+	public static bool operator == (BindData x, BindData y)
+	{
+		return x.Equals (y);
+	}
+
+	public static bool operator != (BindData x, BindData y)
+	{
+		return !(x == y);
+	}
+	
+	/// <inheritdoc />
+	public override string ToString ()
+	{
+		return $"{{ BindSelector: '{Selector}', Virtual: {Virtual} }}";
+	}
+}
diff --git a/tests/rgen/Microsoft.Macios.Transformer.Tests/Attributes/BindDataTests.cs b/tests/rgen/Microsoft.Macios.Transformer.Tests/Attributes/BindDataTests.cs
new file mode 100644
index 00000000000..1deb642c204
--- /dev/null
+++ b/tests/rgen/Microsoft.Macios.Transformer.Tests/Attributes/BindDataTests.cs
@@ -0,0 +1,92 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System.Collections;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.Macios.Generator.Extensions;
+using Microsoft.Macios.Transformer.Attributes;
+using Xamarin.Tests;
+using Xamarin.Utils;
+
+namespace Microsoft.Macios.Transformer.Tests.Attributes;
+
+public class BindDataTests : BaseTransformerTestClass {
+	
+	class TestDataTryCreate : IEnumerable<object []> {
+		public IEnumerator<object []> GetEnumerator ()
+		{
+			var path = "/some/random/path.cs";
+			var simpleBind = @"
+using System;
+using Foundation;
+using ObjCRuntime;
+using UIKit;
+
+namespace Test;
+
+[NoTV]
+[MacCatalyst (13, 1)]
+[DisableDefaultCtor]
+[Abstract]
+[BaseType (typeof (NSObject))]
+interface UIFeedbackGenerator : UIInteraction {
+
+	[Bind (""someSelector"")]
+	void Prepare ();
+}
+";
+			
+			yield return [(Sorunce: simpleBind, Path: path), new BindData ("someSelector")];
+			
+			var virtualBind = @"
+using System;
+using Foundation;
+using ObjCRuntime;
+using UIKit;
+
+namespace Test;
+
+[NoTV]
+[MacCatalyst (13, 1)]
+[DisableDefaultCtor]
+[Abstract]
+[BaseType (typeof (NSObject))]
+interface UIFeedbackGenerator : UIInteraction {
+
+	[Bind (""someSelector"", Virtual = true)]
+	void Prepare ();
+}
+";
+			
+			yield return [(Sorunce: virtualBind, Path: path), new BindData ("someSelector", true)];
+		}
+
+		IEnumerator IEnumerable.GetEnumerator () => GetEnumerator ();
+	}
+
+	[Theory]
+	[AllSupportedPlatformsClassData<TestDataTryCreate>]
+	void TryeCreateTests (ApplePlatform platform, (string Source, string Path) source,
+		BindData expectedData)
+	{
+		// create a compilation used to create the transformer
+		var compilation = CreateCompilation (platform, sources: source);
+		var syntaxTree = compilation.SyntaxTrees.ForSource (source);
+		Assert.NotNull (syntaxTree);
+
+		var semanticModel = compilation.GetSemanticModel (syntaxTree);
+		Assert.NotNull (semanticModel);
+
+		var declaration = syntaxTree.GetRoot ()
+			.DescendantNodes ().OfType<MethodDeclarationSyntax> ()
+			.LastOrDefault ();
+		Assert.NotNull (declaration);
+
+		var symbol = semanticModel.GetDeclaredSymbol (declaration);
+		Assert.NotNull (symbol);
+		var exportData = symbol.GetAttribute<BindData> (
+			AttributesNames.BindAttribute, BindData.TryParse);
+		Assert.Equal (expectedData, exportData);
+	}
+}