diff --git a/RxPack/RxMessagePortDemo/AppDelegate.swift b/RxPack/RxMessagePortDemo/AppDelegate.swift
index cee9c31a..923df9bd 100644
--- a/RxPack/RxMessagePortDemo/AppDelegate.swift
+++ b/RxPack/RxMessagePortDemo/AppDelegate.swift
@@ -8,13 +8,12 @@ import RxSwift
 
 @NSApplicationMain
 class AppDelegate: NSObject, NSApplicationDelegate {
+  @IBOutlet var window: NSWindow!
 
-  @IBOutlet weak var window: NSWindow!
+  @IBOutlet var clientTextField: NSTextField!
 
-  @IBOutlet weak var clientTextField: NSTextField!
-
-  @IBOutlet weak var serverTextView: NSTextView!
-  @IBOutlet weak var clientTextView: NSTextView!
+  @IBOutlet var serverTextView: NSTextView!
+  @IBOutlet var clientTextView: NSTextView!
 
   private let server = RxMessagePortServer()
   private let client = RxMessagePortClient()
@@ -23,18 +22,18 @@ class AppDelegate: NSObject, NSApplicationDelegate {
 
   private let disposeBag = DisposeBag()
 
-  @IBAction func serverStop(sender: Any?) {
+  @IBAction func serverStop(sender _: Any?) {
     self.server.stop().subscribe().disposed(by: self.disposeBag)
   }
 
-  @IBAction func clientStop(sender: Any?) {
+  @IBAction func clientStop(sender _: Any?) {
     self.client.stop().subscribe().disposed(by: self.disposeBag)
   }
 
-  @IBAction func clientSend(sender: Any?) {
+  @IBAction func clientSend(sender _: Any?) {
     let text = self.clientTextField.stringValue
 
-    logClient("Sending msg (\(msgid), \(text))")
+    self.logClient("Sending msg (\(self.msgid), \(text))")
     self.client.send(msgid: self.msgid, data: text.data(using: .utf8)!, expectsReply: true)
       .observeOn(MainScheduler.instance)
       .subscribe(onSuccess: { data in
@@ -51,7 +50,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
     self.msgid += 1
   }
 
-  func applicationDidFinishLaunching(_ aNotification: Notification) {
+  func applicationDidFinishLaunching(_: Notification) {
     self
       .startServer()
       .andThen(self.startClient())
@@ -69,13 +68,13 @@ class AppDelegate: NSObject, NSApplicationDelegate {
       .disposed(by: self.disposeBag)
   }
 
-  func applicationWillTerminate(_ notification: Notification) {
+  func applicationWillTerminate(_: Notification) {
     self.client.stop().subscribe().disposed(by: self.disposeBag)
     self.server.stop().subscribe().disposed(by: self.disposeBag)
   }
 
   private func startServer() -> Completable {
-    logServer("Starting server...")
+    self.logServer("Starting server...")
 
     self.server.stream
       .observeOn(MainScheduler.instance)
@@ -114,7 +113,6 @@ class AppDelegate: NSObject, NSApplicationDelegate {
 }
 
 extension NSTextView {
-
   func append(string: String) {
     self.textStorage?.append(NSAttributedString(string: string))
     self.scrollToEndOfDocument(nil)
diff --git a/RxPack/RxMsgpackRpcTests/RxMsgpackRpcTests.swift b/RxPack/RxMsgpackRpcTests/RxMsgpackRpcTests.swift
index a9ea0257..f5814ca4 100644
--- a/RxPack/RxMsgpackRpcTests/RxMsgpackRpcTests.swift
+++ b/RxPack/RxMsgpackRpcTests/RxMsgpackRpcTests.swift
@@ -3,11 +3,10 @@
  * See LICENSE
  */
 
-import XCTest
 import RxSwift
+import XCTest
 
 class RxMsgpackRpcTests: XCTestCase {
-
   private var connection: RxMsgpackRpc!
   private let disposeBag = DisposeBag()
 
@@ -15,8 +14,8 @@ class RxMsgpackRpcTests: XCTestCase {
     super.setUp()
 
     // $ NVIM_LISTEN_ADDRESS=/tmp/nvim.sock nvim --headless $SOMEFILE
-    connection = RxMsgpackRpc()
-    connection.stream
+    self.connection = RxMsgpackRpc()
+    self.connection.stream
       .subscribe(onNext: { msg in
         switch msg {
         case let .notification(method, params):
@@ -29,8 +28,8 @@ class RxMsgpackRpcTests: XCTestCase {
       }, onError: { print("ERROR: \($0)") })
       .disposed(by: self.disposeBag)
 
-    _ = connection.run(at: "/tmp/nvim.sock")
-      .andThen(connection.request(
+    _ = self.connection.run(at: "/tmp/nvim.sock")
+      .andThen(self.connection.request(
         method: "nvim_ui_attach",
         params: [.int(40), .int(40), .map([:])],
         expectsReturnValue: true
@@ -53,7 +52,7 @@ class RxMsgpackRpcTests: XCTestCase {
   func testExample() {
     let disposeBag = DisposeBag()
 
-    let lineCount = connection
+    let lineCount = self.connection
       .request(
         method: "nvim_buf_line_count",
         params: [.int(0)],
@@ -64,7 +63,7 @@ class RxMsgpackRpcTests: XCTestCase {
 
     let formatter = DateFormatter()
     formatter.dateFormat = "mm:ss.SSS"
-    for i in 0...100 {
+    for i in 0 ... 100 {
       let date = Date()
       connection
         .request(
diff --git a/RxPack/RxNeovimApiTests/RxNeovimApiTests.swift b/RxPack/RxNeovimApiTests/RxNeovimApiTests.swift
index 4afce3ae..c00f535b 100644
--- a/RxPack/RxNeovimApiTests/RxNeovimApiTests.swift
+++ b/RxPack/RxNeovimApiTests/RxNeovimApiTests.swift
@@ -3,12 +3,11 @@
  * See LICENSE
  */
 
-import XCTest
-import RxSwift
 import MessagePack
+import RxSwift
+import XCTest
 
 class NvimMsgPackTests: XCTestCase {
-
   var nvim = RxNeovimApi()
   let disposeBag = DisposeBag()
 
@@ -16,7 +15,7 @@ class NvimMsgPackTests: XCTestCase {
     super.setUp()
 
     // $ NVIM_LISTEN_ADDRESS=/tmp/nvim.sock nvim $SOME_FILES
-    try? nvim.run(at: "/tmp/nvim.sock").wait()
+    try? self.nvim.run(at: "/tmp/nvim.sock").wait()
   }
 
   override func tearDown() {
@@ -33,7 +32,7 @@ class NvimMsgPackTests: XCTestCase {
       "Question", // blockquote foreground
     ]
 
-    typealias HlResult = Dictionary<String, RxNeovimApi.Value>
+    typealias HlResult = [String: RxNeovimApi.Value]
     typealias ColorNameHlResultTuple = (colorName: String, hlResult: HlResult)
     typealias ColorNameObservableTuple = (colorName: String, observable: Observable<HlResult>)
 
@@ -82,8 +81,8 @@ class NvimMsgPackTests: XCTestCase {
     formatter.timeStyle = .full
     let now = Date()
     let dispose = DisposeBag()
-    for i in 0...5 {
-      nvim
+    for i in 0 ... 5 {
+      self.nvim
         .command(
           command: "echo '\(formatter.string(from: now)) \(i)'"
         )