diff --git a/Sources/SKTestSupport/TestJSONRPCConnection.swift b/Sources/SKTestSupport/TestJSONRPCConnection.swift
deleted file mode 100644
index 19a45e466..000000000
--- a/Sources/SKTestSupport/TestJSONRPCConnection.swift
+++ /dev/null
@@ -1,238 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// This source file is part of the Swift.org open source project
-//
-// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
-// Licensed under Apache License v2.0 with Runtime Library Exception
-//
-// See https://swift.org/LICENSE.txt for license information
-// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
-//
-//===----------------------------------------------------------------------===//
-
-import InProcessClient
-@_spi(SourceKitLSP) public import LanguageServerProtocol
-@_spi(SourceKitLSP) import LanguageServerProtocolExtensions
-@_spi(SourceKitLSP) package import LanguageServerProtocolTransport
-import SwiftExtensions
-@_spi(SourceKitLSP) import ToolsProtocolsSwiftExtensions
-import XCTest
-
-package import class Foundation.Pipe
-
-package final class TestJSONRPCConnection: Sendable {
-  package let clientToServer: Pipe = Pipe()
-  package let serverToClient: Pipe = Pipe()
-
-  /// Mocks a client (aka. editor) that can send requests to the LSP server.
-  package let client: TestClient
-
-  /// The connection with which the client can send requests and notifications to the LSP server and using which it
-  /// receives replies to the requests.
-  package let clientToServerConnection: JSONRPCConnection
-
-  /// Mocks an LSP server that handles requests from the client.
-  package let server: TestServer
-
-  /// The connection with which the server can send requests and notifications to the client and using which it
-  /// receives replies to the requests.
-  package let serverToClientConnection: JSONRPCConnection
-
-  package init(allowUnexpectedNotification: Bool = true) {
-    clientToServerConnection = JSONRPCConnection(
-      name: "client",
-      protocol: testMessageRegistry,
-      inFD: serverToClient.fileHandleForReading,
-      outFD: clientToServer.fileHandleForWriting
-    )
-
-    serverToClientConnection = JSONRPCConnection(
-      name: "server",
-      protocol: testMessageRegistry,
-      inFD: clientToServer.fileHandleForReading,
-      outFD: serverToClient.fileHandleForWriting
-    )
-
-    client = TestClient(
-      connectionToServer: clientToServerConnection,
-      allowUnexpectedNotification: allowUnexpectedNotification
-    )
-    server = TestServer(client: serverToClientConnection)
-
-    clientToServerConnection.start(receiveHandler: client) {
-      // Keep the pipes alive until we close the connection.
-      withExtendedLifetime(self) {}
-    }
-    serverToClientConnection.start(receiveHandler: server) {
-      // Keep the pipes alive until we close the connection.
-      withExtendedLifetime(self) {}
-    }
-  }
-
-  package func close() {
-    clientToServerConnection.close()
-    serverToClientConnection.close()
-  }
-}
-
-package struct TestLocalConnection {
-  package let client: TestClient
-  package let clientConnection: LocalConnection = LocalConnection(receiverName: "Test")
-  package let server: TestServer
-  package let serverConnection: LocalConnection = LocalConnection(receiverName: "Test")
-
-  package init(allowUnexpectedNotification: Bool = true) {
-    client = TestClient(connectionToServer: serverConnection, allowUnexpectedNotification: allowUnexpectedNotification)
-    server = TestServer(client: clientConnection)
-
-    clientConnection.start(handler: client)
-    serverConnection.start(handler: server)
-  }
-
-  package func close() {
-    clientConnection.close()
-    serverConnection.close()
-  }
-}
-
-package actor TestClient: MessageHandler {
-  /// The connection to the LSP server.
-  package let connectionToServer: any Connection
-
-  private let messageHandlingQueue = AsyncQueue<Serial>()
-
-  private var oneShotNotificationHandlers: [((Any) -> Void)] = []
-
-  private let allowUnexpectedNotification: Bool
-
-  package init(connectionToServer: any Connection, allowUnexpectedNotification: Bool = true) {
-    self.connectionToServer = connectionToServer
-    self.allowUnexpectedNotification = allowUnexpectedNotification
-  }
-
-  package func appendOneShotNotificationHandler<N: NotificationType>(_ handler: @escaping (N) -> Void) {
-    oneShotNotificationHandlers.append({ anyNotification in
-      guard let notification = anyNotification as? N else {
-        fatalError("received notification of the wrong type \(anyNotification); expected \(N.self)")
-      }
-      handler(notification)
-    })
-  }
-
-  /// The LSP server sent a notification to the client. Handle it.
-  package nonisolated func handle(_ notification: some NotificationType) {
-    messageHandlingQueue.async {
-      await self.handleNotificationImpl(notification)
-    }
-  }
-
-  package func handleNotificationImpl(_ notification: some NotificationType) {
-    guard !oneShotNotificationHandlers.isEmpty else {
-      if allowUnexpectedNotification { return }
-      fatalError("unexpected notification \(notification)")
-    }
-    let handler = oneShotNotificationHandlers.removeFirst()
-    handler(notification)
-  }
-
-  /// The LSP server sent a request to the client. Handle it.
-  package nonisolated func handle<Request: RequestType>(
-    _ request: Request,
-    id: RequestID,
-    reply: @escaping (LSPResult<Request.Response>) -> Void
-  ) {
-    reply(.failure(.methodNotFound(Request.method)))
-  }
-
-  /// Send a notification to the LSP server.
-  package nonisolated func send(_ notification: some NotificationType) {
-    connectionToServer.send(notification)
-  }
-
-  /// Send a request to the LSP server and (asynchronously) receive a reply.
-  package nonisolated func send<Request: RequestType>(
-    _ request: Request,
-    reply: @Sendable @escaping (LSPResult<Request.Response>) -> Void
-  ) -> RequestID {
-    return connectionToServer.send(request, reply: reply)
-  }
-}
-
-package final class TestServer: MessageHandler {
-  package let client: any Connection
-
-  init(client: any Connection) {
-    self.client = client
-  }
-
-  /// The client sent a notification to the server. Handle it.
-  package func handle(_ notification: some NotificationType) {
-    if notification is EchoNotification {
-      self.client.send(notification)
-    } else {
-      fatalError("Unhandled notification")
-    }
-  }
-
-  /// The client sent a request to the server. Handle it.
-  package func handle<Request: RequestType>(
-    _ request: Request,
-    id: RequestID,
-    reply: @escaping (LSPResult<Request.Response>) -> Void
-  ) {
-    if let params = request as? EchoRequest {
-      reply(.success(params.string as! Request.Response))
-    } else if let params = request as? EchoError {
-      if let code = params.code {
-        reply(.failure(ResponseError(code: code, message: params.message!)))
-      } else {
-        reply(.success(VoidResponse() as! Request.Response))
-      }
-    } else {
-      fatalError("Unhandled request")
-    }
-  }
-}
-
-// MARK: Test requests
-
-private let testMessageRegistry = MessageRegistry(
-  requests: [EchoRequest.self, EchoError.self],
-  notifications: [EchoNotification.self, ShowMessageNotification.self]
-)
-
-extension String: LanguageServerProtocol.ResponseType {}
-
-package struct EchoRequest: RequestType {
-  package static let method: String = "test_server/echo"
-  package typealias Response = String
-
-  package var string: String
-
-  package init(string: String) {
-    self.string = string
-  }
-}
-
-package struct EchoError: RequestType {
-  package static let method: String = "test_server/echo_error"
-  package typealias Response = VoidResponse
-
-  package var code: ErrorCode?
-  package var message: String?
-
-  package init(code: ErrorCode? = nil, message: String? = nil) {
-    self.code = code
-    self.message = message
-  }
-}
-
-package struct EchoNotification: NotificationType {
-  package static let method: String = "test_server/echo_note"
-
-  package var string: String
-
-  package init(string: String) {
-    self.string = string
-  }
-}