Add Wrappers for Class, Actor, Extension, along with DeclGroupProtocol and ModifierProtocol (#17)

* add missing wrappers

* swift-format

* add inherited types

* swift-format

* Remove RawRepresentable Conformance

* remove AnyDeclProtocol

* swift-format

* swift-format is whack

Author: ajkolean

Sources/MacroToolkit/ClassRestrictionType.swift

@@ -5,7 +5,10 @@ public struct ClassRestrictionType: TypeProtocol {
     public var _baseSyntax: ClassRestrictionTypeSyntax
     public var _attributedSyntax: AttributedTypeSyntax?
 
-    public init(_ syntax: ClassRestrictionTypeSyntax, attributedSyntax: AttributedTypeSyntax? = nil) {
+    public init(
+        _ syntax: ClassRestrictionTypeSyntax,
+        attributedSyntax: AttributedTypeSyntax? = nil
+    ) {
         _baseSyntax = syntax
         _attributedSyntax = attributedSyntax
     }

Sources/MacroToolkit/DeclGroup.swift

@@ -0,0 +1,19 @@
+import SwiftSyntax
+
+/// Wraps an `actor` declaration.
+public struct Actor: DeclGroupProtocol, RepresentableBySyntax {
+    /// The underlying syntax node for the `actor` declaration.
+    public var _syntax: ActorDeclSyntax
+
+    /// The identifier (name) of the `actor`.
+    public var identifier: String {
+        _syntax.name.withoutTrivia().text
+    }
+
+    /// Initializes an `Actor` instance with the given syntax node.
+    ///
+    /// - Parameter syntax: The syntax node representing the `actor` declaration.
+    public init(_ syntax: ActorDeclSyntax) {
+        _syntax = syntax
+    }
+}

Sources/MacroToolkit/DeclGroup/Actor.swift

@@ -0,0 +1,19 @@
+import SwiftSyntax
+
+/// Wraps a `class` declaration.
+public struct Class: DeclGroupProtocol, RepresentableBySyntax {
+    /// The underlying syntax node for the `class` declaration.
+    public var _syntax: ClassDeclSyntax
+
+    /// The identifier (name) of the `class`.
+    public var identifier: String {
+        _syntax.name.withoutTrivia().text
+    }
+
+    /// Initializes a `Class` instance with the given syntax node.
+    ///
+    /// - Parameter syntax: The syntax node representing the `class` declaration.
+    public init(_ syntax: ClassDeclSyntax) {
+        _syntax = syntax
+    }
+}

Sources/MacroToolkit/DeclGroup/Class.swift

@@ -0,0 +1,57 @@
+import SwiftSyntax
+
+/// An enum that encapsulates various types of declaration groups (`struct`, `class`, `enum`, `actor`, `extension`)
+/// and provides a unified interface for interacting with them. This enum conforms to `DeclGroupProtocol`,
+/// allowing access to common properties of declaration groups.
+public enum DeclGroup: DeclGroupProtocol {
+    case `struct`(Struct)
+    case `enum`(Enum)
+    case `class`(Class)
+    case `actor`(Actor)
+    case `extension`(Extension)
+
+    /// A private computed property that returns the wrapped `DeclGroupProtocol` instance.
+    ///
+    /// This property is used internally to access the underlying implementation of the declaration group.
+    private var wrapped: any DeclGroupProtocol {
+        switch self {
+            case .struct(let wrapped): return wrapped
+            case .enum(let wrapped): return wrapped
+            case .class(let wrapped): return wrapped
+            case .actor(let wrapped): return wrapped
+            case .extension(let wrapped): return wrapped
+        }
+    }
+
+    /// Initializes a `DeclGroup` instance from a `DeclGroupSyntax`.
+    ///
+    /// - Parameter syntax: The syntax node representing the declaration group.
+    /// - Note: This initializer will fatalError if the syntax node does not match any known declaration group type.
+    public init(_ syntax: DeclGroupSyntax) {
+        if let syntax = syntax.as(ActorDeclSyntax.self) {
+            self = .actor(Actor(syntax))
+        } else if let syntax = syntax.as(ClassDeclSyntax.self) {
+            self = .class(Class(syntax))
+        } else if let syntax = syntax.as(EnumDeclSyntax.self) {
+            self = .enum(Enum(syntax))
+        } else if let syntax = syntax.as(ExtensionDeclSyntax.self) {
+            self = .extension(Extension(syntax))
+        } else if let syntax = syntax.as(StructDeclSyntax.self) {
+            self = .struct(Struct(syntax))
+        } else {
+            fatalError("Unhandled decl group type '\(type(of: syntax))'")
+        }
+    }
+
+    /// The identifier of the declaration group.
+    public var identifier: String { wrapped.identifier }
+
+    /// All members declared within the declaration group.
+    public var members: [Decl] { wrapped.members }
+
+    /// All properties declared within the declaration group.
+    public var properties: [Property] { wrapped.properties }
+
+    /// All types that the declaration group inherits from or conforms to.
+    public var inheritedTypes: [Type] { wrapped.inheritedTypes }
+}

Sources/MacroToolkit/DeclGroup/DeclGroup.swift

@@ -0,0 +1,64 @@
+import SwiftSyntax
+
+/// A protocol that represents a declaration group, such as a `struct`, `class`, `enum`, or `protocol`.
+/// This protocol defines common properties that all declaration groups should have.
+public protocol DeclGroupProtocol {
+    /// The identifier of the declaration group.
+    var identifier: String { get }
+
+    /// All members declared within the declaration group.
+    var members: [Decl] { get }
+
+    /// All properties declared within the declaration group.
+    var properties: [Property] { get }
+
+    /// All types that the declaration group inherits from or conforms to.
+    var inheritedTypes: [Type] { get }
+}
+
+extension DeclGroupProtocol where UnderlyingSyntax: DeclGroupSyntax, Self: RepresentableBySyntax {
+    /// Attempts to initialize the wrapper from an arbitrary declaration group.
+    ///
+    /// - Parameter syntax: The syntax node representing the declaration group.
+    /// - Note: This initializer will return `nil` if the syntax node does not match the expected type.
+    public init?(_ syntax: any DeclGroupSyntax) {
+        guard let syntax = syntax as? UnderlyingSyntax else { return nil }
+        self.init(syntax)
+    }
+
+    public var members: [Decl] {
+        _syntax.memberBlock.members.map(\.decl).map(Decl.init)
+    }
+
+    public var properties: [Property] {
+        members.compactMap(\.asVariable).flatMap { variable in
+            var bindings = variable._syntax.bindings.flatMap { binding in
+                Property.properties(from: binding, in: variable)
+            }
+            // For the declaration `var a, b: Int` where `a` doesn't have an annotation,
+            // `a` gets given the type of `b` (`Int`). To implement this, we 'drag' the
+            // type annotations backwards over the non-annotated bindings.
+            var lastSeenType: Type?
+            for (i, binding) in bindings.enumerated().reversed() {
+                if let type = binding.type {
+                    lastSeenType = type
+                } else {
+                    bindings[i].type = lastSeenType
+                }
+            }
+            return bindings
+        }
+    }
+
+    public var inheritedTypes: [Type] {
+        _syntax.inheritanceClause?.inheritedTypes.map(\.type).map(Type.init) ?? []
+    }
+
+    public var accessLevel: AccessModifier? {
+        AccessModifier(firstModifierOfKindIn: _syntax.modifiers)
+    }
+
+    public var declarationContext: DeclarationContextModifier? {
+        DeclarationContextModifier(firstModifierOfKindIn: _syntax.modifiers)
+    }
+}

Sources/MacroToolkit/DeclGroup/DeclGroupProtocol.swift

@@ -1,13 +1,18 @@
 import SwiftSyntax
 
 /// Wraps an `enum` declaration.
-public struct Enum: DeclGroupProtocol {
+public struct Enum: DeclGroupProtocol, RepresentableBySyntax {
+    /// The underlying syntax node for the `enum` declaration.
     public var _syntax: EnumDeclSyntax
 
+    /// The identifier (name) of the `enum`.
     public var identifier: String {
         _syntax.name.withoutTrivia().text
     }
 
+    /// Initializes an `Enum` instance with the given syntax node.
+    ///
+    /// - Parameter syntax: The syntax node representing the `enum` declaration.
     public init(_ syntax: EnumDeclSyntax) {
         _syntax = syntax
     }

Sources/MacroToolkit/Enum.swift renamed to Sources/MacroToolkit/DeclGroup/Enum.swift

@@ -0,0 +1,19 @@
+import SwiftSyntax
+
+/// Wraps an `extension` declaration.
+public struct Extension: DeclGroupProtocol, RepresentableBySyntax {
+    /// The underlying syntax node for the `extension` declaration.
+    public var _syntax: ExtensionDeclSyntax
+
+    /// The identifier (extended type) of the `extension`.
+    public var identifier: String {
+        _syntax.extendedType.withoutTrivia().description
+    }
+
+    /// Initializes an `Extension` instance with the given syntax node.
+    ///
+    /// - Parameter syntax: The syntax node representing the `extension` declaration.
+    public init(_ syntax: ExtensionDeclSyntax) {
+        _syntax = syntax
+    }
+}

Sources/MacroToolkit/DeclGroup/Extension.swift

@@ -0,0 +1,19 @@
+import SwiftSyntax
+
+/// Wraps a `struct` declaration.
+public struct Struct: DeclGroupProtocol, RepresentableBySyntax {
+    /// The underlying syntax node for the `struct` declaration.
+    public var _syntax: StructDeclSyntax
+
+    /// The identifier (name) of the `struct`.
+    public var identifier: String {
+        _syntax.name.withoutTrivia().text
+    }
+
+    /// Initializes a `Struct` instance with the given syntax node.
+    ///
+    /// - Parameter syntax: The syntax node representing the `struct` declaration.
+    public init(_ syntax: StructDeclSyntax) {
+        _syntax = syntax
+    }
+}