Rework lint

.github/workflows/swift.yml

@@ -47,7 +47,12 @@ jobs:
     runs-on: macos-15
     steps:
     - uses: actions/checkout@v4
+    - name: Set up Homebrew
+      id: set-up-homebrew
+      uses: Homebrew/actions/setup-homebrew@master
+    - name: Install swiftformat
+      run: brew install swiftformat
     - name: Run linter
-      run: swift package --allow-writing-to-package-directory format
-    - name: Verify that `swift package --allow-writing-to-package-directory format` did not change outputs (if it did, please re-run it and re-commit!)
+      run: swiftformat --config rules.swiftformat .
+    - name: Verify that `swiftformat --config rules.swiftformat .` did not change outputs (if it did, please re-run it and re-commit!)
       run: git diff --exit-code

.gitignore

@@ -60,4 +60,6 @@ Carthage/Build/
 fastlane/report.xml
 fastlane/Preview.html
 fastlane/screenshots/**/*.png
-fastlane/test_output
+fastlane/test_output
+.DS_Store
+.vscode

MCPClient/Sources/MCPClient.swift

@@ -8,8 +8,6 @@ import MCPInterface
 
 public actor MCPClient: MCPClientInterface {
 
-  // MARK: Lifecycle
-
   /// Creates a MCP client and connects to the server through the provided transport.
   /// The methods completes after connecting to the server.
   public init(
@@ -19,7 +17,7 @@ public actor MCPClient: MCPClientInterface {
   async throws {
     try await self.init(
       capabilities: capabilities,
-      connection: try MCPClientConnection(
+      connection: MCPClientConnection(
         info: info,
         capabilities: ClientCapabilities(
           experimental: nil, // TODO: support experimental requests
@@ -47,31 +45,29 @@ public actor MCPClient: MCPClientInterface {
     Task { try await self.updateResourceTemplates() }
   }
 
-  // MARK: Public
-
   public private(set) var serverInfo: ServerInfo
 
   public var tools: ReadOnlyCurrentValueSubject<CapabilityStatus<[Tool]>, Never> {
     get async {
-      await .init(_tools.compactMap { $0 }.removeDuplicates().eraseToAnyPublisher())
+      await .init(_tools.compactMap(\.self).removeDuplicates().eraseToAnyPublisher())
     }
   }
 
   public var prompts: ReadOnlyCurrentValueSubject<CapabilityStatus<[Prompt]>, Never> {
     get async {
-      await .init(_prompts.compactMap { $0 }.removeDuplicates().eraseToAnyPublisher())
+      await .init(_prompts.compactMap(\.self).removeDuplicates().eraseToAnyPublisher())
     }
   }
 
   public var resources: ReadOnlyCurrentValueSubject<CapabilityStatus<[Resource]>, Never> {
     get async {
-      await .init(_resources.compactMap { $0 }.removeDuplicates().eraseToAnyPublisher())
+      await .init(_resources.compactMap(\.self).removeDuplicates().eraseToAnyPublisher())
     }
   }
 
   public var resourceTemplates: ReadOnlyCurrentValueSubject<CapabilityStatus<[ResourceTemplate]>, Never> {
     get async {
-      await .init(_resourceTemplates.compactMap { $0 }.removeDuplicates().eraseToAnyPublisher())
+      await .init(_resourceTemplates.compactMap(\.self).removeDuplicates().eraseToAnyPublisher())
     }
   }
 
@@ -99,7 +95,7 @@ public actor MCPClient: MCPClientInterface {
     }
     // If there has been an error during the execution, throw it
     if result.isError == true {
-      let errors = result.content.compactMap { $0.text }.map { CallToolResult.ExecutionError(text: $0.text) }
+      let errors = result.content.compactMap(\.text).map { CallToolResult.ExecutionError(text: $0.text) }
       throw MCPClientError.toolCallError(executionErrors: errors)
     }
     return result
@@ -119,12 +115,8 @@ public actor MCPClient: MCPClientInterface {
     return try await connection.readResource(.init(uri: uri))
   }
 
-  // MARK: Internal
-
   let connection: MCPClientConnectionInterface
 
-  // MARK: Private
-
   private let capabilities: ClientCapabilityHandlers
 
   private let _tools = CurrentValueSubject<CapabilityStatus<[Tool]>?, Never>(nil)
@@ -185,7 +177,7 @@ public actor MCPClient: MCPClientInterface {
   private func startListeningToRequests() async {
     let requests = await connection.requestsToHandle
     Task { [weak self] in
-      for await(request, completion) in requests {
+      for await (request, completion) in requests {
         guard let self else {
           completion(.failure(.init(
             code: JRPCErrorCodes.internalError.rawValue,
@@ -210,7 +202,7 @@ public actor MCPClient: MCPClientInterface {
   {
     if let handler {
       do {
-        return .success(try await handler(params))
+        return try await .success(handler(params))
       } catch {
         return .failure(.init(
           code: JRPCErrorCodes.internalError.rawValue,

MCPClient/Sources/MCPClientConnection.swift

@@ -7,8 +7,6 @@ import MemberwiseInit
 
 public actor MCPClientConnection: MCPClientConnectionInterface {
 
-  // MARK: Lifecycle
-
   public init(
     info: Implementation,
     capabilities: ClientCapabilities,
@@ -21,8 +19,6 @@ public actor MCPClientConnection: MCPClientConnectionInterface {
     self.capabilities = capabilities
   }
 
-  // MARK: Public
-
   public let info: Implementation
 
   public let capabilities: ClientCapabilities
@@ -108,8 +104,6 @@ public actor MCPClientConnection: MCPClientConnectionInterface {
     try await jrpcSession.send(RootsListChangedNotification())
   }
 
-  // MARK: Private
-
   private let _connection: MCPConnection<ServerRequest, ServerNotification>
 
   private var jrpcSession: JSONRPCSession {

MCPClient/Sources/MCPClientInterface.swift

@@ -65,9 +65,9 @@ extension MCPClientError: LocalizedError {
   public var errorDescription: String? {
     switch self {
     case .versionMismatch(let received, let expected):
-      return "Version mismatch between server and client. Received: \(received), Expected: \(expected)"
+      "Version mismatch between server and client. Received: \(received), Expected: \(expected)"
     case .toolCallError(let executionErrors):
-      return "Error executing tool:\n\(executionErrors.map { $0.errorDescription ?? "unknown error" }.joined(separator: "\n\n"))"
+      "Error executing tool:\n\(executionErrors.map { $0.errorDescription ?? "unknown error" }.joined(separator: "\n\n"))"
     }
   }
 }

MCPClient/Sources/Process+extensions.swift

@@ -35,12 +35,12 @@ extension Process {
   func finish() throws {
     /// The full path to the executable + all arguments, each one quoted if it contains a space.
     func commandAsString() -> String {
-      let path: String
-      if #available(OSX 10.13, *) {
-        path = self.executableURL?.path ?? ""
-      } else {
-        path = launchPath ?? ""
-      }
+      let path: String =
+        if #available(OSX 10.13, *) {
+          self.executableURL?.path ?? ""
+        } else {
+          launchPath ?? ""
+        }
       return (arguments ?? []).reduce(path) { (acc: String, arg: String) in
         acc + " " + (arg.contains(" ") ? ("\"" + arg + "\"") : arg)
       }
@@ -66,9 +66,9 @@ enum CommandError: Error, Equatable {
   public var errorcode: Int {
     switch self {
     case .returnedErrorCode(_, let code):
-      return code
+      code
     case .inAccessibleExecutable:
-      return 127 // according to http://tldp.org/LDP/abs/html/exitcodes.html
+      127 // according to http://tldp.org/LDP/abs/html/exitcodes.html
     }
   }
 }
@@ -79,9 +79,9 @@ extension CommandError: CustomStringConvertible {
   public var description: String {
     switch self {
     case .inAccessibleExecutable(let path):
-      return "Could not execute file at path '\(path)'."
+      "Could not execute file at path '\(path)'."
     case .returnedErrorCode(let command, let code):
-      return "Command '\(command)' returned with error code \(code)."
+      "Command '\(command)' returned with error code \(code)."
     }
   }
 }

MCPClient/Sources/stdioTransport/DataChannel+StdioProcess.swift

@@ -23,30 +23,28 @@ extension JSONRPCSetupError: LocalizedError {
   public var errorDescription: String? {
     switch self {
     case .missingStandardIO:
-      return "Missing standard IO"
+      "Missing standard IO"
     case .couldNotLocateExecutable(let executable, let error):
-      return "Could not locate executable \(executable) \(error ?? "")".trimmingCharacters(in: .whitespaces)
+      "Could not locate executable \(executable) \(error ?? "")".trimmingCharacters(in: .whitespaces)
     case .standardIOConnectionError(let message):
-      return "Could not connect to stdio: \(message)".trimmingCharacters(in: .whitespaces)
+      "Could not connect to stdio: \(message)".trimmingCharacters(in: .whitespaces)
     }
   }
 
   public var recoverySuggestion: String? {
     switch self {
     case .missingStandardIO:
-      return "Make sure that the Process that is passed as an argument has stdin, stdout and stderr set as a Pipe."
+      "Make sure that the Process that is passed as an argument has stdin, stdout and stderr set as a Pipe."
     case .couldNotLocateExecutable:
-      return "Check that the executable is findable given the PATH environment variable. If needed, pass the right environment to the process."
+      "Check that the executable is findable given the PATH environment variable. If needed, pass the right environment to the process."
     case .standardIOConnectionError:
-      return nil
+      nil
     }
   }
 }
 
 extension Transport {
 
-  // MARK: Public
-
   /// Creates a new `Transport` by launching the given executable with the specified arguments and attaching to its standard IO.
   public static func stdioProcess(
     _ executable: String,
@@ -193,8 +191,6 @@ extension Transport {
     return Transport(writeHandler: writeHandler, dataSequence: outStream)
   }
 
-  // MARK: Private
-
   /// Finds the full path to the executable using the `which` command.
   private static func locate(executable: String, env: [String: String]? = nil) throws -> String {
     let process = Process()
@@ -266,8 +262,6 @@ extension Transport {
 
 final class Lifetime {
 
-  // MARK: Lifecycle
-
   init(onDeinit: @escaping () -> Void) {
     self.onDeinit = onDeinit
   }
@@ -276,8 +270,6 @@ final class Lifetime {
     onDeinit()
   }
 
-  // MARK: Private
-
   private let onDeinit: () -> Void
 
 }

MCPClient/Tests/Initialization.swift

@@ -95,7 +95,7 @@ extension MCPClientTestSuite {
             """),
         ])
 
-      let clientCapabilities = await(client.connection as? MCPClientConnection)?.capabilities
+      let clientCapabilities = await (client.connection as? MCPClientConnection)?.capabilities
       #expect(clientCapabilities?.roots?.listChanged == true)
       #expect(clientCapabilities?.sampling != nil)
     }

MCPClient/Tests/MCPClientTests.swift

@@ -12,8 +12,6 @@ class MCPClientTestSuite { }
 
 class MCPClientTest {
 
-  // MARK: Lifecycle
-
   init() {
     version = "1.0.0"
     name = "TestClient"
@@ -42,8 +40,6 @@ class MCPClientTest {
     connection.listResourceTemplatesStub = { [] }
   }
 
-  // MARK: Internal
-
   let version: String
   let capabilities: ClientCapabilities
   let name: String

MCPClient/Tests/MockMCPClientConnection.swift

@@ -7,8 +7,6 @@ import MCPInterface
 /// A mock `MCPClientConnection` that can be used in tests.
 class MockMCPClientConnection: MCPClientConnectionInterface {
 
-  // MARK: Lifecycle
-
   required init(info: Implementation, capabilities: ClientCapabilities, transport _: Transport = .noop) throws {
     self.info = info
     self.capabilities = capabilities
@@ -26,8 +24,6 @@ class MockMCPClientConnection: MCPClientConnectionInterface {
     self.sendRequestToStream = sendRequestToStream
   }
 
-  // MARK: Internal
-
   /// Send a server notification.
   private(set) var sendNotificationToStream: ((ServerNotification) -> Void) = { _ in }
   /// Send a server request to the handler.

MCPClient/Tests/ServerRequests.swift

@@ -24,7 +24,7 @@ extension MCPClientTestSuite {
         do {
           let success = try response.get()
           let roots = try #require(success as? ListRootsResult)
-          #expect(roots.roots.map { $0.uri } == ["//root"])
+          #expect(roots.roots.map(\.uri) == ["//root"])
           expectation.fulfill()
         } catch {
           Issue.record(error)

MCPClientChatDemo/MCPClientChat/MCPClientChat/Chat/Models/AnthropicNonStreamManager.swift

@@ -12,19 +12,15 @@ import MCPInterface
 import SwiftAnthropic
 import SwiftUI
 
+/// Handle a chat conversation without stream.
 @MainActor
 @Observable
-/// Handle a chat conversation without stream.
 final class AnthropicNonStreamManager: ChatManager {
 
-  // MARK: Lifecycle
-
   init(service: AnthropicService) {
     self.service = service
   }
 
-  // MARK: Internal
-
   /// Messages sent from the user or received from Claude
   var messages = [ChatMessage]()
 
@@ -66,8 +62,6 @@ final class AnthropicNonStreamManager: ChatManager {
     task = nil
   }
 
-  // MARK: Private
-
   /// Service to communicate with Anthropic API
   private let service: AnthropicService
 

MCPClientChatDemo/MCPClientChat/MCPClientChat/Chat/Models/OpenAIChatNonStreamManager.swift

@@ -12,19 +12,15 @@ import MCPInterface
 import SwiftOpenAI
 import SwiftUI
 
+/// Handle a chat conversation without stream for OpenAI.
 @MainActor
 @Observable
-/// Handle a chat conversation without stream for OpenAI.
 final class OpenAIChatNonStreamManager: ChatManager {
 
-  // MARK: Lifecycle
-
   init(service: OpenAIService) {
     self.service = service
   }
 
-  // MARK: Internal
-
   /// Messages sent from the user or received from OpenAI
   var messages = [ChatMessage]()
 
@@ -66,8 +62,6 @@ final class OpenAIChatNonStreamManager: ChatManager {
     task = nil
   }
 
-  // MARK: Private
-
   /// Service to communicate with OpenAI API
   private let service: OpenAIService
 

MCPClientChatDemo/MCPClientChat/MCPClientChat/Chat/UI/ChatInputView.swift

@@ -10,8 +10,6 @@ import SwiftUI
 /// A view for the user to enter chat messages
 struct ChatInputView: View {
 
-  // MARK: Internal
-
   /// Is a streaming chat response in progress
   let isStreamingResponse: Bool
 
@@ -29,8 +27,6 @@ struct ChatInputView: View {
     .padding(8)
   }
 
-  // MARK: Private
-
   private enum FocusedField {
     case newMessageText
   }