fix: review fixes of the latest changes

Author: yehorsobko-mac

Package.resolved

@@ -3,28 +3,6 @@
 
 import PackageDescription
 
-// Base dependencies needed on all platforms
-var dependencies: [Package.Dependency] = [
-    .package(url: "https://github.com/apple/swift-system.git", from: "1.0.0"),
-    .package(url: "https://github.com/apple/swift-log.git", from: "1.5.0"),
-    .package(url: "https://github.com/apple/swift-async-algorithms.git", from: "1.0.0"),
-    .package(url: "https://github.com/mattt/eventsource.git", from: "1.1.0"),
-    .package(url: "https://github.com/apple/swift-nio.git", from: "2.65.0"),
-]
-
-// Target dependencies needed on all platforms
-var targetDependencies: [Target.Dependency] = [
-    .product(name: "SystemPackage", package: "swift-system"),
-    .product(name: "Logging", package: "swift-log"),
-    .product(name: "AsyncAlgorithms", package: "swift-async-algorithms"),
-    .product(
-        name: "EventSource", package: "eventsource",
-        condition: .when(platforms: [.macOS, .iOS, .tvOS, .visionOS, .watchOS, .macCatalyst])),
-    .product(name: "NIOCore", package: "swift-nio"),
-    .product(name: "NIOPosix", package: "swift-nio"),
-    .product(name: "NIOHTTP1", package: "swift-nio"),
-]
-
 let package = Package(
     name: "mcp-swift-sdk",
     platforms: [
@@ -47,27 +25,55 @@ let package = Package(
             name: "mcp-everything-client",
             targets: ["MCPConformanceClient"])
     ],
-    dependencies: dependencies,
+    dependencies: [
+        .package(url: "https://github.com/apple/swift-system.git", from: "1.0.0"),
+        .package(url: "https://github.com/apple/swift-log.git", from: "1.5.0"),
+        .package(url: "https://github.com/mattt/eventsource.git", from: "1.1.0"),
+        .package(url: "https://github.com/apple/swift-nio.git", from: "2.65.0"),
+    ],
     targets: [
-        // Targets are the basic building blocks of a package, defining a module or a test suite.
-        // Targets can depend on other targets in this package and products from dependencies.
         .target(
             name: "MCP",
-            dependencies: targetDependencies,
+            dependencies: [
+                .product(name: "SystemPackage", package: "swift-system"),
+                .product(name: "Logging", package: "swift-log"),
+                .product(
+                    name: "EventSource", package: "eventsource",
+                    condition: .when(platforms: [.macOS, .iOS, .tvOS, .visionOS, .watchOS, .macCatalyst])),
+            ],
             swiftSettings: [
                 .enableUpcomingFeature("StrictConcurrency")
             ]
         ),
         .testTarget(
             name: "MCPTests",
-            dependencies: ["MCP"] + targetDependencies),
+            dependencies: [
+                "MCP",
+                .product(name: "SystemPackage", package: "swift-system"),
+                .product(name: "Logging", package: "swift-log"),
+                .product(
+                    name: "EventSource", package: "eventsource",
+                    condition: .when(platforms: [.macOS, .iOS, .tvOS, .visionOS, .watchOS, .macCatalyst])),
+            ]
+        ),
         .executableTarget(
             name: "MCPConformanceServer",
-            dependencies: ["MCP"] + targetDependencies,
-            path: "Sources/MCPConformance/Server"),
+            dependencies: [
+                "MCP",
+                .product(name: "Logging", package: "swift-log"),
+                .product(name: "NIOCore", package: "swift-nio"),
+                .product(name: "NIOPosix", package: "swift-nio"),
+                .product(name: "NIOHTTP1", package: "swift-nio"),
+            ],
+            path: "Sources/MCPConformance/Server"
+        ),
         .executableTarget(
             name: "MCPConformanceClient",
-            dependencies: ["MCP"] + targetDependencies,
-            path: "Sources/MCPConformance/Client")
+            dependencies: [
+                "MCP",
+                .product(name: "Logging", package: "swift-log"),
+            ],
+            path: "Sources/MCPConformance/Client"
+        )
     ]
 )

Package.swift

@@ -279,7 +279,21 @@ extension MCPError: Codable {
 
 extension MCPError: Equatable {
     public static func == (lhs: MCPError, rhs: MCPError) -> Bool {
-        lhs.code == rhs.code
+        switch (lhs, rhs) {
+        case (.parseError(let a), .parseError(let b)): return a == b
+        case (.invalidRequest(let a), .invalidRequest(let b)): return a == b
+        case (.methodNotFound(let a), .methodNotFound(let b)): return a == b
+        case (.invalidParams(let a), .invalidParams(let b)): return a == b
+        case (.internalError(let a), .internalError(let b)): return a == b
+        case (.serverError(let c1, let m1), .serverError(let c2, let m2)):
+            return c1 == c2 && m1 == m2
+        case (.urlElicitationRequired(let m1, let e1), .urlElicitationRequired(let m2, let e2)):
+            return m1 == m2 && e1 == e2
+        case (.connectionClosed, .connectionClosed): return true
+        case (.transportError(let a), .transportError(let b)):
+            return a.localizedDescription == b.localizedDescription
+        default: return false
+        }
     }
 }
 

Sources/MCP/Base/Error.swift

@@ -38,10 +38,9 @@ struct AnyMethod: Method, Sendable {
 
 extension Method where Parameters == Empty {
     public static func request(
-        id: ID = .random,
-        _meta: Metadata? = nil
+        id: ID = .random
     ) -> Request<Self> {
-        Request(id: id, method: name, params: Empty(), _meta: _meta)
+        Request(id: id, method: name, params: Empty())
     }
 }
 
@@ -55,28 +54,25 @@ extension Method {
     /// Create a request with the given parameters.
     public static func request(
         id: ID = .random,
-        _ parameters: Self.Parameters,
-        _meta: Metadata? = nil
+        _ parameters: Self.Parameters
     ) -> Request<Self> {
-        Request(id: id, method: name, params: parameters, _meta: _meta)
+        Request(id: id, method: name, params: parameters)
     }
 
     /// Create a response with the given result.
     public static func response(
         id: ID,
-        result: Self.Result,
-        _meta: Metadata? = nil
+        result: Self.Result
     ) -> Response<Self> {
-        Response(id: id, result: result, _meta: _meta)
+        Response(id: id, result: result)
     }
 
     /// Create a response with the given error.
     public static func response(
         id: ID,
-        error: MCPError,
-        _meta: Metadata? = nil
+        error: MCPError
     ) -> Response<Self> {
-        Response(id: id, error: error, _meta: _meta)
+        Response(id: id, error: error)
     }
 }
 
@@ -90,23 +86,19 @@ public struct Request<M: Method>: Hashable, Identifiable, Codable, Sendable {
     public let method: String
     /// The request parameters.
     public let params: M.Parameters
-    /// Metadata for this request (see spec for _meta usage, includes progressToken)
-    public let _meta: Metadata?
 
     init(
         id: ID = .random,
         method: String,
-        params: M.Parameters,
-        _meta: Metadata? = nil
+        params: M.Parameters
     ) {
         self.id = id
         self.method = method
         self.params = params
-        self._meta = _meta
     }
 
     private enum CodingKeys: String, CodingKey, CaseIterable {
-        case jsonrpc, id, method, params, _meta
+        case jsonrpc, id, method, params
     }
 
     public func encode(to encoder: Encoder) throws {
@@ -115,7 +107,6 @@ public struct Request<M: Method>: Hashable, Identifiable, Codable, Sendable {
         try container.encode(id, forKey: .id)
         try container.encode(method, forKey: .method)
         try container.encode(params, forKey: .params)
-        try container.encodeIfPresent(_meta, forKey: ._meta)
     }
 }
 
@@ -129,7 +120,6 @@ extension Request {
         }
         id = try container.decode(ID.self, forKey: .id)
         method = try container.decode(String.self, forKey: .method)
-        _meta = try container.decodeIfPresent(Metadata.self, forKey: ._meta)
 
         if M.Parameters.self is NotRequired.Type {
             // For NotRequired parameters, use decodeIfPresent or init()
@@ -221,44 +211,37 @@ public struct Response<M: Method>: Hashable, Identifiable, Codable, Sendable {
     public let id: ID
     /// The response result.
     public let result: Swift.Result<M.Result, MCPError>
-    /// Metadata for this response (see spec for _meta usage)
-    public let _meta: Metadata?
 
     public init(
         id: ID,
-        result: Swift.Result<M.Result, MCPError>,
-        _meta: Metadata? = nil
+        result: Swift.Result<M.Result, MCPError>
     ) {
         self.id = id
         self.result = result
-        self._meta = _meta
     }
 
     public init(
         id: ID,
-        result: M.Result,
-        _meta: Metadata? = nil
+        result: M.Result
     ) {
-        self.init(id: id, result: .success(result), _meta: _meta)
+        self.init(id: id, result: .success(result))
     }
 
     public init(
         id: ID,
-        error: MCPError,
-        _meta: Metadata? = nil
+        error: MCPError
     ) {
-        self.init(id: id, result: .failure(error), _meta: _meta)
+        self.init(id: id, result: .failure(error))
     }
 
     private enum CodingKeys: String, CodingKey, CaseIterable {
-        case jsonrpc, id, result, error, _meta
+        case jsonrpc, id, result, error
     }
 
     public func encode(to encoder: Encoder) throws {
         var container = encoder.container(keyedBy: CodingKeys.self)
         try container.encode(jsonrpc, forKey: .jsonrpc)
         try container.encode(id, forKey: .id)
-        try container.encodeIfPresent(_meta, forKey: ._meta)
 
         switch result {
         case .success(let result):
@@ -286,7 +269,6 @@ public struct Response<M: Method>: Hashable, Identifiable, Codable, Sendable {
                     codingPath: container.codingPath,
                     debugDescription: "Invalid response"))
         }
-        _meta = try container.decodeIfPresent(Metadata.self, forKey: ._meta)
     }
 }
 
@@ -301,14 +283,12 @@ extension AnyResponse {
             let resultValue = try JSONDecoder().decode(Value.self, from: data)
             self = Response<AnyMethod>(
                 id: response.id,
-                result: .success(resultValue),
-                _meta: response._meta
+                result: .success(resultValue)
             )
         case .failure(let error):
             self = Response<AnyMethod>(
                 id: response.id,
-                result: .failure(error),
-                _meta: response._meta
+                result: .failure(error)
             )
         }
     }

Sources/MCP/Base/Messages.swift

@@ -0,0 +1,43 @@
+import class Foundation.JSONDecoder
+import class Foundation.JSONEncoder
+
+/// An error indicating a type mismatch when decoding a pending request response.
+struct TypeMismatchError: Swift.Error {}
+
+/// A pending request with a continuation for the result.
+struct PendingRequest<T> {
+    let continuation: CheckedContinuation<T, Swift.Error>
+}
+
+/// A type-erased pending request.
+struct AnyPendingRequest: Sendable {
+    private let _resume: @Sendable (Result<Any, Swift.Error>) -> Void
+
+    init<T: Sendable & Decodable>(_ request: PendingRequest<T>) {
+        _resume = { result in
+            switch result {
+            case .success(let value):
+                if let typedValue = value as? T {
+                    request.continuation.resume(returning: typedValue)
+                } else if let value = value as? Value,
+                    let data = try? JSONEncoder().encode(value),
+                    let decoded = try? JSONDecoder().decode(T.self, from: data)
+                {
+                    request.continuation.resume(returning: decoded)
+                } else {
+                    request.continuation.resume(throwing: TypeMismatchError())
+                }
+            case .failure(let error):
+                request.continuation.resume(throwing: error)
+            }
+        }
+    }
+
+    func resume(returning value: Any) {
+        _resume(.success(value))
+    }
+
+    func resume(throwing error: Swift.Error) {
+        _resume(.failure(error))
+    }
+}

Sources/MCP/Base/PendingRequest.swift

@@ -15,13 +15,13 @@ public struct CancelledNotification: Notification {
         /// The ID of the request to cancel.
         ///
         /// This MUST correspond to the ID of a request previously issued
-        /// in the same direction.
-        public let requestId: ID
+        /// in the same direction. Optional per the spec (`requestId?`).
+        public let requestId: ID?
 
         /// An optional human-readable reason for the cancellation.
         public let reason: String?
 
-        public init(requestId: ID, reason: String? = nil) {
+        public init(requestId: ID? = nil, reason: String? = nil) {
             self.requestId = requestId
             self.reason = reason
         }