Refactor 'if let' to 'guard let' in 'Tests'

Author: Daniel Browne

Tests/Helpers/Helpers.swift

@@ -3,15 +3,18 @@ import Foundation
 @testable import PusherSwift
 
 func convertStringToDictionary(_ text: String) -> [String: AnyObject]? {
-    if let data = text.data(using: .utf8) {
-        do {
-            let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: AnyObject]
-            return json
-        } catch {
-            print("Something went wrong")
-        }
+    guard let data = text.data(using: .utf8) else {
+        return nil
+    }
+
+    do {
+        let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: AnyObject]
+        return json
+    } catch {
+        print("Something went wrong")
+        
+        return nil
     }
-    return nil
 }
 
 extension AuthMethod: Equatable {

Tests/Integration/AuthenticationTests.swift

@@ -10,9 +10,11 @@ class AuthenticationTests: XCTestCase {
         var testingChannelName: String?
 
         func subscribedToChannel(name: String) {
-            if let cName = testingChannelName, cName == name {
-                ex!.fulfill()
+            guard let cName = testingChannelName, cName == name else {
+                return
             }
+
+            ex!.fulfill()
         }
     }
 
@@ -126,11 +128,15 @@ class AuthenticationTests: XCTestCase {
         XCTAssertFalse(chan.subscribed, "the channel should not be subscribed")
 
         _ = pusher.bind({ (data: Any?) -> Void in
-            if let data = data as? [String: AnyObject], let eventName = data["event"] as? String, eventName == "pusher:subscription_error" {
-                XCTAssertEqual("private-test-channel", data["channel"] as? String)
-                XCTAssertTrue(Thread.isMainThread)
-                ex.fulfill()
+            guard let data = data as? [String: AnyObject],
+                  let eventName = data["event"] as? String,
+                  eventName == "pusher:subscription_error" else {
+                return
             }
+            
+            XCTAssertEqual("private-test-channel", data["channel"] as? String)
+            XCTAssertTrue(Thread.isMainThread)
+            ex.fulfill()
         })
 
         pusher.connect()

Tests/Integration/PusherIncomingEventHandlingTests.swift

@@ -235,12 +235,16 @@ class HandlingIncomingEventsTests: XCTestCase {
         let ex = expectation(description: "Callback should be called")
 
         _ = pusher.bind({ (message: Any?) in
-            if let message = message as? [String: AnyObject], let eventName = message["event"] as? String, eventName == "pusher:error" {
-                if let data = message["data"] as? [String: AnyObject], let errorMessage = data["message"] as? String {
-                    XCTAssertEqual(errorMessage, "Existing subscription to channel my-channel")
-                    ex.fulfill()
-                }
+            guard let message = message as? [String: AnyObject],
+               let eventName = message["event"] as? String,
+               eventName == "pusher:error",
+               let data = message["data"] as? [String: AnyObject],
+               let errorMessage = data["message"] as? String else {
+                return
             }
+
+            XCTAssertEqual(errorMessage, "Existing subscription to channel my-channel")
+            ex.fulfill()
         })
         // pretend that we tried to subscribe to my-channel twice and got this error
         // back from Pusher

Tests/Integration/PusherTopLevelAPITests.swift

@@ -16,10 +16,12 @@ class PusherTopLevelApiTests: XCTestCase {
         }
 
         func changedConnectionState(from old: ConnectionState, to new: ConnectionState) {
-            if let stateCallbacks = callbacks[new] {
-                for callback in stateCallbacks {
-                    callback()
-                }
+            guard let stateCallbacks = callbacks[new] else {
+                return
+            }
+
+            for callback in stateCallbacks {
+                callback()
             }
         }
     }
@@ -30,9 +32,12 @@ class PusherTopLevelApiTests: XCTestCase {
         var connectionStubber = StubberForMocks()
 
         func subscribedToChannel(name: String) {
-            if let cName = testingChannelName, cName == name {
-                ex!.fulfill()
+            guard let cName = testingChannelName,
+                  cName == name else {
+                return
             }
+
+            ex!.fulfill()
         }
 
         func changedConnectionState(from old: ConnectionState, to new: ConnectionState) {
@@ -170,13 +175,15 @@ class PusherTopLevelApiTests: XCTestCase {
             _ = self.pusher.subscribe("test-channel")
 
             self.socket.stubber.registerCallback { calls in
-                if let name = calls.last?.name, name == "writeString" {
-                    let parsedSubscribeArgs = convertStringToDictionary(calls.last?.args!.first as! String)
-                    let expectedDict = ["data": ["channel": "test-channel"], "event": "pusher:subscribe"] as [String: Any]
-                    let parsedEqualsExpected = NSDictionary(dictionary: parsedSubscribeArgs!).isEqual(to: NSDictionary(dictionary: expectedDict) as [NSObject: AnyObject])
-                    XCTAssertTrue(parsedEqualsExpected)
-                    subscribed.fulfill()
+                guard let name = calls.last?.name, name == "writeString" else {
+                    return
                 }
+
+                let parsedSubscribeArgs = convertStringToDictionary(calls.last?.args!.first as! String)
+                let expectedDict = ["data": ["channel": "test-channel"], "event": "pusher:subscribe"] as [String: Any]
+                let parsedEqualsExpected = NSDictionary(dictionary: parsedSubscribeArgs!).isEqual(to: NSDictionary(dictionary: expectedDict) as [NSObject: AnyObject])
+                XCTAssertTrue(parsedEqualsExpected)
+                subscribed.fulfill()
             }
         }
 
@@ -201,9 +208,13 @@ class PusherTopLevelApiTests: XCTestCase {
         let ex = expectation(description: "should call global callback")
         pusher.connect()
         let callback = { (data: Any?) -> Void in
-            if let data = data as? [String: Any], let eName = data["event"] as? String, eName == "pusher:subscription_succeeded" {
-                ex.fulfill()
+            guard let data = data as? [String: Any],
+                  let eName = data["event"] as? String,
+                  eName == "pusher:subscription_succeeded" else {
+                return
             }
+
+            ex.fulfill()
         }
         _ = pusher.bind(callback)
         _ = pusher.subscribe("test-channel")
@@ -368,13 +379,16 @@ class PusherTopLevelApiTests: XCTestCase {
         }
         let ex = expectation(description: "should send unsubscribe")
         socket.stubber.registerCallback { calls in
-            if let name = calls.last?.name, name == "writeString" {
-                let parsedSubscribeArgs = convertStringToDictionary(calls.last?.args!.first as! String)
-                let expectedDict = ["data": ["channel": "test-channel"], "event": "pusher:unsubscribe"] as [String: Any]
-                let parsedEqualsExpected = NSDictionary(dictionary: parsedSubscribeArgs!).isEqual(to: NSDictionary(dictionary: expectedDict) as [NSObject: AnyObject])
-                if parsedEqualsExpected {
-                    ex.fulfill()
-                }
+            guard let name = calls.last?.name,
+                  name == "writeString" else {
+                return
+            }
+
+            let parsedSubscribeArgs = convertStringToDictionary(calls.last?.args!.first as! String)
+            let expectedDict = ["data": ["channel": "test-channel"], "event": "pusher:unsubscribe"] as [String: Any]
+            let parsedEqualsExpected = NSDictionary(dictionary: parsedSubscribeArgs!).isEqual(to: NSDictionary(dictionary: expectedDict) as [NSObject: AnyObject])
+            if parsedEqualsExpected {
+                ex.fulfill()
             }
         }
         waitForExpectations(timeout: 0.5)

Tests/Unit/Models/ClientEventTests.swift

@@ -47,12 +47,14 @@ class ClientEventTests: XCTestCase {
         let ex = expectation(description: "send client event eventually")
         socket.stubber.registerCallback { calls in
             let expectedDict = ["data": ["data": "testing client events"], "event": "client-test-event", "channel": "private-channel"] as [String: Any]
-            if let lastCall = calls.last, lastCall.name == "writeString" {
-                let parsedSubscribeArgs = convertStringToDictionary(lastCall.args!.first as! String)
-                let parsedEqualsExpected = NSDictionary(dictionary: parsedSubscribeArgs!).isEqual(to: NSDictionary(dictionary: expectedDict) as [NSObject: AnyObject])
-                if parsedEqualsExpected {
-                    ex.fulfill()
-                }
+            guard let lastCall = calls.last, lastCall.name == "writeString" else {
+                return
+            }
+
+            let parsedSubscribeArgs = convertStringToDictionary(lastCall.args!.first as! String)
+            let parsedEqualsExpected = NSDictionary(dictionary: parsedSubscribeArgs!).isEqual(to: NSDictionary(dictionary: expectedDict) as [NSObject: AnyObject])
+            if parsedEqualsExpected {
+                ex.fulfill()
             }
         }
         connection.connect()
@@ -71,13 +73,15 @@ class ClientEventTests: XCTestCase {
 
         let ex = expectation(description: "send client event eventually")
         socket.stubber.registerCallback { calls in
-            if let lastCall = calls.last, lastCall.name == "writeString" {
-                let parsedSubscribeArgs = convertStringToDictionary(lastCall.args!.first as! String)
-                let expectedDict = ["data": ["data": "more testing client events"], "event": "client-test-event", "channel": "private-channel"] as [String: Any]
-                let parsedEqualsExpected = NSDictionary(dictionary: parsedSubscribeArgs!).isEqual(to: NSDictionary(dictionary: expectedDict) as [NSObject: AnyObject])
-                if parsedEqualsExpected {
-                    ex.fulfill()
-                }
+            guard let lastCall = calls.last, lastCall.name == "writeString" else {
+                return
+            }
+
+            let parsedSubscribeArgs = convertStringToDictionary(lastCall.args!.first as! String)
+            let expectedDict = ["data": ["data": "more testing client events"], "event": "client-test-event", "channel": "private-channel"] as [String: Any]
+            let parsedEqualsExpected = NSDictionary(dictionary: parsedSubscribeArgs!).isEqual(to: NSDictionary(dictionary: expectedDict) as [NSObject: AnyObject])
+            if parsedEqualsExpected {
+                ex.fulfill()
             }
 
         }

Tests/Unit/Protocols/PusherConnectionDelegateTests.swift

@@ -24,15 +24,19 @@ class PusherConnectionDelegateTests: XCTestCase {
         }
 
         open func subscribedToChannel(name: String) {
-            if let cName = testingChannelName, cName == name {
-                ex!.fulfill()
+            guard let cName = testingChannelName, cName == name else {
+                return
             }
+
+            ex!.fulfill()
         }
 
         open func failedToSubscribeToChannel(name: String, response: URLResponse?, data: String?, error: NSError?) {
-            if let cName = testingChannelName, cName == name {
-                ex!.fulfill()
+            guard let cName = testingChannelName, cName == name else {
+                return
             }
+
+            ex!.fulfill()
         }
 
         open func receivedError(error: PusherError) {