Merge pull request #5 from WendellXY/add-codable-options-support

Add `skipSuperCoding` Codable Options

Sources/CodableKit/CodableKit.swift

@@ -56,7 +56,9 @@
 /// ```
 @attached(extension, conformances: Codable, names: named(CodingKeys), named(init(from:)))
 @attached(member, conformances: Codable, names: named(init(from:)), named(encode(to:)))
-public macro Codable() = #externalMacro(module: "CodableKitMacros", type: "CodableMacro")
+public macro Codable(
+  options: CodableOptions = .default
+) = #externalMacro(module: "CodableKitMacros", type: "CodableMacro")
 
 /// A macro that generates `Decodable` conformance and boilerplate code for a struct, such that the Decodable struct can
 /// have default values for its properties, and custom keys for encoding and decoding with `@CodableKey`.
@@ -96,7 +98,9 @@ public macro Codable() = #externalMacro(module: "CodableKitMacros", type: "Codab
 /// ```
 @attached(extension, conformances: Decodable, names: named(CodingKeys), named(init(from:)))
 @attached(member, conformances: Decodable, names: named(init(from:)))
-public macro Decodable() = #externalMacro(module: "CodableKitMacros", type: "CodableMacro")
+public macro Decodable(
+  options: CodableOptions = .default
+) = #externalMacro(module: "CodableKitMacros", type: "CodableMacro")
 
 /// A macro that generates `Encodable` conformance and boilerplate code for a struct, such that the Encodable struct can
 /// have default values for its properties, and custom keys for encoding and decoding with `@CodableKey`.
@@ -136,7 +140,9 @@ public macro Decodable() = #externalMacro(module: "CodableKitMacros", type: "Cod
 /// ```
 @attached(extension, conformances: Encodable, names: named(CodingKeys))
 @attached(member, conformances: Encodable, names: named(encode(to:)))
-public macro Encodable() = #externalMacro(module: "CodableKitMacros", type: "CodableMacro")
+public macro Encodable(
+  options: CodableOptions = .default
+) = #externalMacro(module: "CodableKitMacros", type: "CodableMacro")
 
 /// Custom the key used for encoding and decoding a property.
 ///

Sources/CodableKitMacros/CodableMacro.swift

@@ -5,6 +5,7 @@
 //  Created by Wendell on 3/30/24.
 //
 
+import CodableKitShared
 import Foundation
 import SwiftDiagnostics
 import SwiftSyntax
@@ -25,18 +26,22 @@ extension CodableMacro: ExtensionMacro {
     conformingTo protocols: [TypeSyntax],
     in context: some MacroExpansionContext
   ) throws -> [ExtensionDeclSyntax] {
-    try core.prepareCodeGeneration(for: declaration, in: context, conformingTo: protocols)
+    try core.prepareCodeGeneration(of: node, for: declaration, in: context, conformingTo: protocols)
 
     let properties = try core.properties(for: declaration, in: context)
     let accessModifier = try core.accessModifier(for: declaration, in: context)
     let structureType = try core.accessStructureType(for: declaration, in: context)
     let codableType = try core.accessCodableType(for: declaration, in: context)
+    let codableOptions = try core.accessCodableOptions(for: declaration, in: context)
 
     // If there are no properties, return an empty array.
     guard !properties.isEmpty else { return [] }
 
     let inheritanceClause: InheritanceClauseSyntax? =
-      if case .classType(let hasSuperclass) = structureType, hasSuperclass {
+      if case .classType(let hasSuperclass) = structureType,
+        hasSuperclass,
+        !codableOptions.contains(.skipSuperCoding)
+      {
         nil
       } else {
         InheritanceClauseSyntax {
@@ -62,7 +67,14 @@ extension CodableMacro: ExtensionMacro {
         ) {
           genCodingKeyEnumDecl(from: properties)
           if codableType.contains(.decodable) {
-            DeclSyntax(genInitDecoderDecl(from: properties, modifiers: [accessModifier], hasSuper: false))
+            DeclSyntax(
+              genInitDecoderDecl(
+                from: properties,
+                modifiers: [accessModifier],
+                codableOptions: codableOptions,
+                hasSuper: false
+              )
+            )
           }
         }
       ]
@@ -87,12 +99,13 @@ extension CodableMacro: MemberMacro {
     conformingTo protocols: [TypeSyntax],
     in context: some MacroExpansionContext
   ) throws -> [DeclSyntax] {
-    try core.prepareCodeGeneration(for: declaration, in: context, conformingTo: protocols)
+    try core.prepareCodeGeneration(of: node, for: declaration, in: context, conformingTo: protocols)
 
     let properties = try core.properties(for: declaration, in: context)
     let accessModifier = try core.accessModifier(for: declaration, in: context)
     let structureType = try core.accessStructureType(for: declaration, in: context)
     let codableType = try core.accessCodableType(for: declaration, in: context)
+    let codableOptions = try core.accessCodableOptions(for: declaration, in: context)
 
     // If there are no properties, return an empty array.
     guard !properties.isEmpty else { return [] }
@@ -108,7 +121,9 @@ extension CodableMacro: MemberMacro {
     case let .classType(hasSuperclass):
       decodeModifiers.append(.init(name: .keyword(.required)))
       if hasSuperclass {
-        encodeModifiers.append(.init(name: .keyword(.override)))
+        if !codableOptions.contains(.skipSuperCoding) {
+          encodeModifiers.append(.init(name: .keyword(.override)))
+        }
         hasSuper = true
       }
     case .structType, .enumType:
@@ -121,14 +136,28 @@ extension CodableMacro: MemberMacro {
     case .classType:
       if codableType.contains(.decodable) {
         result.append(
-          DeclSyntax(genInitDecoderDecl(from: properties, modifiers: decodeModifiers, hasSuper: hasSuper))
+          DeclSyntax(
+            genInitDecoderDecl(
+              from: properties,
+              modifiers: decodeModifiers,
+              codableOptions: codableOptions,
+              hasSuper: hasSuper
+            )
+          )
         )
       }
       fallthrough
     case .structType:
       if codableType.contains(.encodable) {
         result.append(
-          DeclSyntax(genEncodeFuncDecl(from: properties, modifiers: encodeModifiers, hasSuper: hasSuper))
+          DeclSyntax(
+            genEncodeFuncDecl(
+              from: properties,
+              modifiers: encodeModifiers,
+              codableOptions: codableOptions,
+              hasSuper: hasSuper
+            )
+          )
         )
       }
     case .enumType:
@@ -170,6 +199,7 @@ extension CodableMacro {
   fileprivate static func genInitDecoderDecl(
     from properties: [Property],
     modifiers: [DeclModifierSyntax],
+    codableOptions: CodableOptions,
     hasSuper: Bool
   ) -> InitializerDeclSyntax {
     InitializerDeclSyntax(
@@ -231,7 +261,11 @@ extension CodableMacro {
       }
 
       if hasSuper {
-        "try super.init(from: decoder)"
+        if codableOptions.contains(.skipSuperCoding) {
+          "super.init()"
+        } else {
+          "try super.init(from: decoder)"
+        }
       }
     }
   }
@@ -240,6 +274,7 @@ extension CodableMacro {
   fileprivate static func genEncodeFuncDecl(
     from properties: [Property],
     modifiers: [DeclModifierSyntax],
+    codableOptions: CodableOptions,
     hasSuper: Bool
   ) -> FunctionDeclSyntax {
     FunctionDeclSyntax(
@@ -292,7 +327,7 @@ extension CodableMacro {
         )
       }
 
-      if hasSuper {
+      if hasSuper, !codableOptions.contains(.skipSuperCoding) {
         "try super.encode(to: encoder)"
       }
     }

Sources/CodableKitMacros/CodeGenCore.swift

@@ -6,6 +6,7 @@
 //  Copyright © 2024 WendellXY. All rights reserved.
 //
 
+import CodableKitShared
 import Foundation
 import SwiftDiagnostics
 import SwiftSyntax
@@ -33,6 +34,7 @@ internal final class CodeGenCore: @unchecked Sendable {
   private var accessModifiers: [MacroContextKey: DeclModifierSyntax] = [:]
   private var structureTypes: [MacroContextKey: StructureType] = [:]
   private var codableTypes: [MacroContextKey: CodableType] = [:]
+  private var codableOptions: [MacroContextKey: CodableOptions] = [:]
 
   func key(for declaration: some SyntaxProtocol, in context: some MacroExpansionContext) -> MacroContextKey {
     let location = context.location(of: declaration)
@@ -47,7 +49,10 @@ internal final class CodeGenCore: @unchecked Sendable {
 }
 
 extension CodeGenCore {
-  func properties(for declaration: some SyntaxProtocol, in context: some MacroExpansionContext) throws -> [Property] {
+  func properties(
+    for declaration: some SyntaxProtocol,
+    in context: some MacroExpansionContext
+  ) throws -> [Property] {
     properties[key(for: declaration, in: context)] ?? []
   }
 
@@ -95,6 +100,21 @@ extension CodeGenCore {
       severity: .error
     )
   }
+
+  func accessCodableOptions(
+    for declaration: some SyntaxProtocol,
+    in context: some MacroExpansionContext
+  ) throws -> CodableOptions {
+    if let codableOptions = codableOptions[key(for: declaration, in: context)] {
+      return codableOptions
+    }
+
+    throw SimpleDiagnosticMessage(
+      message: "Codable options for declaration not found",
+      diagnosticID: messageID,
+      severity: .error
+    )
+  }
 }
 
 // MARK: - Property Extraction
@@ -216,6 +236,7 @@ extension CodeGenCore {
 
   /// Prepare the code generation by extracting properties and access modifier.
   func prepareCodeGeneration(
+    of node: AttributeSyntax,
     for declaration: some DeclGroupSyntax,
     in context: some MacroExpansionContext,
     conformingTo protocols: [TypeSyntax] = []
@@ -237,6 +258,11 @@ extension CodeGenCore {
       preparedDeclarations.insert(id)
     }
 
+    codableOptions[id] = node.arguments?
+      .as(LabeledExprListSyntax.self)?
+      .first(where: { $0.label?.text == "options" })?
+      .parseCodableOptions() ?? .default
+
     // Check if properties and access modifier are already prepared
 
     if accessModifiers[id] == nil {

Sources/CodableKitShared/CodableOptions.swift

@@ -0,0 +1,67 @@
+//
+//  CodableOptions.swift
+//  CodableKit
+//
+//  Created by Wendell Wang on 2025/1/13.
+//
+
+import SwiftSyntax
+
+/// Options that customize the behavior of the `@Codable` macro expansion.
+public struct CodableOptions: OptionSet, Sendable {
+  public let rawValue: Int32
+
+  public init(rawValue: Int32) {
+    self.rawValue = rawValue
+  }
+
+  /// The default options, which perform standard Codable expansion with super encode/decode calls.
+  public static let `default`: Self = []
+
+  /// Skips generating super encode/decode calls in the expanded code.
+  ///
+  /// Use this option when the superclass doesn't conform to `Codable`.
+  /// When enabled:
+  /// - Replaces `super.init(from: decoder)` with `super.init()`
+  /// - Removes `super.encode(to: encoder)` call entirely
+  public static let skipSuperCoding = Self(rawValue: 1 << 0)
+}
+
+extension CodableOptions {
+  package init(from expr: MemberAccessExprSyntax) {
+    let variableName = expr.declName.baseName.text
+    switch variableName {
+    case "skipSuperCoding":
+      self = .skipSuperCoding
+    default:
+      self = .default
+    }
+  }
+}
+
+extension CodableOptions {
+  /// Parse the options from 1a `LabelExprSyntax`. It support parse a single element like `.default`,
+  /// or multiple elements like `[.ignored, .explicitNil]`
+  package static func parse(from labeledExpr: LabeledExprSyntax) -> Self {
+    if let memberAccessExpr = labeledExpr.expression.as(MemberAccessExprSyntax.self) {
+      Self.init(from: memberAccessExpr)
+    } else if let arrayExpr = labeledExpr.expression.as(ArrayExprSyntax.self) {
+      arrayExpr.elements
+        .compactMap { $0.expression.as(MemberAccessExprSyntax.self) }
+        .map { Self.init(from: $0) }
+        .reduce(.default) { $0.union($1) }
+    } else {
+      .default
+    }
+  }
+}
+
+extension LabeledExprSyntax {
+  /// Parse the options from a `LabelExprSyntax`. It support parse a single element like .default,
+  /// or multiple elements like [.ignored, .explicitNil].
+  ///
+  /// This is a convenience method to use for chaining.
+  package func parseCodableOptions() -> CodableOptions {
+    CodableOptions.parse(from: self)
+  }
+}

Tests/CodableKitTests/CodableMacroTests+class+inheritance.swift

@@ -736,4 +736,51 @@ final class CodableKitTestsForSubClass: XCTestCase {
     )
 
   }
+
+  func testMacrosWithCodableOptionSkipSuperCoding() throws {
+
+    assertMacroExpansion(
+      """
+      @Codable(options: .skipSuperCoding)
+      public class User: NSObject {
+        let id: UUID
+        let name: String
+        let age: Int
+      }
+      """,
+      expandedSource: """
+        public class User: NSObject {
+          let id: UUID
+          let name: String
+          let age: Int
+
+          public required init(from decoder: any Decoder) throws {
+            let container = try decoder.container(keyedBy: CodingKeys.self)
+            id = try container.decode(UUID.self, forKey: .id)
+            name = try container.decode(String.self, forKey: .name)
+            age = try container.decode(Int.self, forKey: .age)
+            super.init()
+          }
+
+          public func encode(to encoder: any Encoder) throws {
+            var container = encoder.container(keyedBy: CodingKeys.self)
+            try container.encode(id, forKey: .id)
+            try container.encode(name, forKey: .name)
+            try container.encode(age, forKey: .age)
+          }
+        }
+
+        extension User: Codable {
+          enum CodingKeys: String, CodingKey {
+            case id
+            case name
+            case age
+          }
+        }
+        """,
+      macroSpecs: macroSpecs,
+      indentationWidth: .spaces(2)
+    )
+
+  }
 }