Add RequestModifier macro

Author: SwiftyJoeyy

Sources/NetworkingCore/Macros/RequestMacro.swift

@@ -48,10 +48,17 @@ import Foundation
 /// - Note: This macros is needed for the ``Header`` & ``Parameter``
 /// macros to work.
 @attached(extension, conformances: Request, ModifiableRequest)
-@attached(member, conformances: Request, names: named(modifier), named(id))
+@attached(member, conformances: Request, names: named(modifier), named(id), named(_accept))
 public macro Request(_ id: String = "") = #externalMacro(
     module: "NetworkingCoreMacros",
     type: "RequestMacro"
 )
 
 // TODO: - Add support for mods builder in init for composable requests
+
+@attached(extension, conformances: RequestModifier)
+@attached(member, conformances: RequestModifier, names: named(_accept))
+public macro RequestModifier() = #externalMacro(
+    module: "NetworkingCoreMacros",
+    type: "RequestModifierMacro"
+)

Sources/NetworkingCore/Request/AnyRequest.swift

@@ -13,25 +13,17 @@ import Foundation
     public typealias Contents = Never
 
 // MARK: - Properties
-    /// The configuration values available to this instance.
-    @Configurations private var configurations
+    /// The request builder used to type erase a request.
+    private let storage: AnyRequestStorageBase
 
     /// The request's identifier.
     public let id: String
 
-    /// The request builder used to type erase a request.
-    private let requestBuilder: (
-        _ configurations: borrowing ConfigurationValues
-    ) throws -> URLRequest
-    
 // MARK: - Initializer
     /// Create an instance that type-erases `request`.
     public init(_ request: some Request) {
         self.id = request.id
-        self.requestBuilder = { configurations in
-            request._accept(configurations)
-            return try request._makeURLRequest()
-        }
+        self.storage = AnyRequestStorage(request: request)
     }
 
 // MARK: - Functions
@@ -43,7 +35,7 @@ import Foundation
     /// - Returns: The configured ``URLRequest``.
     /// - Note: This type is prefixed with `_` to indicate that it is not intended for public use.
     public func _makeURLRequest() throws -> URLRequest {
-        return try requestBuilder(configurations)
+        return try storage.makeURLRequest()
     }
 
     /// Applies new configuration values to the erased request.
@@ -54,6 +46,52 @@ import Foundation
     /// - Parameter values: The configuration values to apply.
     /// - Note: This type is prefixed with `_` to indicate that it is not intended for public use.
     public func _accept(_ values: ConfigurationValues) {
-        _configurations._accept(values)
+        storage.accept(values)
+    }
+}
+
+extension AnyRequest {
+    /// An abstract base class for type-erased request storage.
+    @usableFromInline internal class AnyRequestStorageBase {
+        /// Creates a ``URLRequest`` from the underlying request.
+        ///
+        /// - Returns: A configured ``URLRequest``.
+        internal func makeURLRequest() throws -> URLRequest {
+            fatalError("Subclasses must override this method.")
+        }
+        
+        /// Applies the specified configuration values to the underlying request.
+        ///
+        /// - Parameter values: The configuration values to apply.
+        internal func accept(_ values: ConfigurationValues) {
+            fatalError("Subclasses must override this method.")
+        }
+    }
+    
+    /// A concrete storage type for a specific ``Request`` instance.
+    fileprivate final class AnyRequestStorage<R: Request>: AnyRequestStorageBase {
+        /// The wrapped request.
+        private let request: R
+        
+        /// Creates a new instance that wraps the given request.
+        ///
+        /// - Parameter request: The request to wrap.
+        fileprivate init(request: R) {
+            self.request = request
+        }
+        
+        /// Builds a ``URLRequest`` from the wrapped request.
+        ///
+        /// - Returns: A configured ``URLRequest``.
+        fileprivate override func makeURLRequest() throws -> URLRequest {
+            return try request._makeURLRequest()
+        }
+        
+        /// Applies the specified configuration values to the wrapped request.
+        ///
+        /// - Parameter values: The configuration values to apply.
+        fileprivate override func accept(_ values: ConfigurationValues) {
+            request._accept(values)
+        }
     }
 }

Sources/NetworkingCore/Request/HTTPRequest.swift

@@ -62,7 +62,7 @@ import Foundation
     private let path: String?
 
     /// The request modifier that defines the request’s behavior.
-    public let modifier: Modifier
+    private let modifier: Modifier
 }
 
 extension HTTPRequest {
@@ -130,7 +130,7 @@ extension HTTPRequest: Request {
 
     /// Applies the given configuration values to the request.
     ///
-    /// This method forwards the provided `ConfigurationValues` to the associated
+    /// This method forwards the provided ``ConfigurationValues`` to the associated
     /// request modifier and to this instance’s internal configuration storage.
     /// Use this to propagate inherited configuration values through the request
     /// chain.

Sources/NetworkingCore/Request/ModifiableRequest.swift

@@ -117,7 +117,7 @@ extension ModifiableRequest {
 /// ```
 @frozen public struct ModifiedRequest<Content: Request, Modifier: RequestModifier>: ModifiableRequest {
     /// The identifier of the underlying request.
-    @inlinable public var id: String {
+    public var id: String {
         return request.id
     }
 

Sources/NetworkingCore/Request/RequestModifier.swift

@@ -56,6 +56,6 @@ extension Request {
     @inlinable public func modifier<Modifier: RequestModifier>(
         _ modifier: Modifier
     ) -> some Request {
-        ModifiedRequest(request: self, modifier: modifier)
+        return ModifiedRequest(request: self, modifier: modifier)
     }
 }

Sources/NetworkingCore/RequestModifiers/CachePolicyRequestModifier.swift

@@ -10,7 +10,7 @@ import Foundation
 /// Request modifier for setting the cache policy for a ``URLRequest``.
 ///
 /// - Note: Use ``Request/cachePolicy(_:)`` instead of directly using this.
-@usableFromInline internal struct CachePolicyRequestModifier {
+@RequestModifier @usableFromInline internal struct CachePolicyRequestModifier {
     /// The cache policy to apply to the request.
     private let cachePolicy: URLRequest.CachePolicy
 
@@ -20,10 +20,7 @@ import Foundation
     @usableFromInline internal init(_ cachePolicy: URLRequest.CachePolicy) {
         self.cachePolicy = cachePolicy
     }
-}
 
-// MARK: - RequestModifier
-extension CachePolicyRequestModifier: RequestModifier {
     /// Modifies the given ``URLRequest`` by setting its cache policy.
     ///
     /// - Parameters:

Sources/NetworkingCore/RequestModifiers/HTTPMethodRequestModifier.swift

@@ -10,7 +10,7 @@ import Foundation
 /// Request modifier for setting the HTTP method of a ``URLRequest``.
 ///
 /// - Note: Use ``Request/method(_:)`` instead of directly using this.
-@usableFromInline internal struct HTTPMethodRequestModifier {
+@RequestModifier @usableFromInline internal struct HTTPMethodRequestModifier {
     /// The HTTP method to apply to the request.
     private let httpMethod: RequestMethod
 
@@ -20,10 +20,7 @@ import Foundation
     @usableFromInline internal init(_ httpMethod: RequestMethod) {
         self.httpMethod = httpMethod
     }
-}
 
-// MARK: - RequestModifier
-extension HTTPMethodRequestModifier: RequestModifier {
     /// Modifies the given ``URLRequest`` by setting its HTTP method.
     ///
     /// - Parameters:

Sources/NetworkingCore/RequestModifiers/PathRequestModifier.swift

@@ -13,7 +13,7 @@ import Foundation
 /// or ``Request/appending(path:)``,
 /// or ``Request/appending(paths:)``
 /// instead of directly using this. 
-@usableFromInline internal struct PathRequestModifier {
+@RequestModifier @usableFromInline internal struct PathRequestModifier {
     /// The list of paths to append.
     private let paths: [String]
 
@@ -23,10 +23,7 @@ import Foundation
     @usableFromInline internal init(_ paths: [String]) {
         self.paths = paths
     }
-}
 
-// MARK: - RequestModifier
-extension PathRequestModifier: RequestModifier {
     /// Modifies the given ``URLRequest`` by appending paths to its URL.
     ///
     /// - Parameters:

Sources/NetworkingCore/RequestModifiers/TimeoutRequestModifier.swift

@@ -10,7 +10,7 @@ import Foundation
 /// Request modifier for setting the timeout interval for a ``URLRequest``
 ///
 /// - Note: Use ``Request/timeout(_:)`` instead of directly using this.
-@usableFromInline internal struct TimeoutRequestModifier {
+@RequestModifier @usableFromInline internal struct TimeoutRequestModifier {
     /// The timeout interval in seconds.
     private let timeoutInterval: TimeInterval
 
@@ -20,10 +20,7 @@ import Foundation
     @usableFromInline internal init(_ timeoutInterval: TimeInterval) {
         self.timeoutInterval = timeoutInterval
     }
-}
 
-// MARK: - RequestModifier
-extension TimeoutRequestModifier: RequestModifier {
     /// Modifies the given ``URLRequest`` by setting its timeout interval.
     ///
     /// - Parameters:

Sources/NetworkingCoreMacros/DynamicConfigurionDeclFactory.swift

@@ -0,0 +1,72 @@
+//
+//  DynamicConfigurionDeclFactory.swift
+//  Networking
+//
+//  Created by Joe Maghzal on 25/05/2025.
+//
+
+import SwiftSyntax
+
+enum DynamicConfigDeclFactory {
+    private static func getConfigsDeclName(
+        declaration: some DeclGroupSyntax
+    ) -> TokenSyntax? {
+        for member in declaration.memberBlock.members {
+            guard let decl = member.decl.as(VariableDeclSyntax.self) else {continue}
+            
+            let hasConfigAttr = decl.attributes.contains { attribute in
+                return attribute.name?.trimmed.text == "Configurations"
+            }
+            
+            if hasConfigAttr {
+                return decl.name
+            }
+        }
+        return nil
+    }
+    
+    static func make(
+        for declaration: some DeclGroupSyntax
+    ) -> FunctionDeclSyntax? {
+        guard let declName = getConfigsDeclName(declaration: declaration) else {
+            return nil
+        }
+        let body: ExprSyntax = """
+        _\(declName)._accept(values)
+        """
+        let type = IdentifierTypeSyntax(name: "ConfigurationValues")
+        let modifiers = declaration.modifiers.filter({$0.name.isAccessLevel})
+        let funcDecl = FunctionDeclSyntax(
+            modifiers: modifiers,
+            name: "_accept",
+            signature: FunctionSignatureSyntax(
+                parameterClause: FunctionParameterClauseSyntax(
+                    parameters: [
+                        FunctionParameterSyntax(
+                            firstName: "_",
+                            secondName: "values",
+                            type: type
+                        )
+                    ]
+                )
+            ),
+            body: CodeBlockSyntax(
+                statements: CodeBlockItemListSyntax(
+                    [CodeBlockItemSyntax(item: .expr(body))]
+                )
+            )
+        )
+        return funcDecl
+    }
+}
+
+extension TokenSyntax {
+    var isAccessLevel: Bool {
+        switch tokenKind {
+            case .keyword(let keyword):
+                return keyword == .public || keyword == .internal || keyword == .fileprivate || keyword == .private || keyword == .fileprivate || keyword == .open || keyword == .package
+            default:
+                return false
+        }
+    }
+}