fix: Fix warnings and prevent potential issues (#165)

* fix: Safer data extraction from numerics

* fix: Swift6 warning and potential deadlock

* fix: Warnings in tests

* fix: Linter check on data decoding

* fix: Malformed events are ignored and then removed silently

Sources/Confidence/ConfidenceScreenTracker.swift

@@ -78,7 +78,7 @@ extension UIViewController {
                 let encoder = JSONEncoder()
                 do {
                     let data = try encoder.encode(trackableWithMessage.trackMessage())
-                    let messageString = String(decoding: data, as: UTF8.self)
+                    let messageString = String(data: data, encoding: .utf8) ?? "internal_error"
                     message.updateValue(messageString, forKey: ConfidenceScreenTracker.messageKey)
                 } catch {
                 }

Sources/Confidence/ConfidenceValueHash.swift

@@ -73,7 +73,21 @@ extension StringProtocol {
     var data: Data { .init(utf8) }
 }
 
-extension Numeric {
+extension FixedWidthInteger {
+    var data: Data {
+        var source = self
+        return .init(bytes: &source, count: MemoryLayout<Self>.size)
+    }
+}
+
+extension Float {
+    var data: Data {
+        var source = self
+        return .init(bytes: &source, count: MemoryLayout<Self>.size)
+    }
+}
+
+extension Double {
     var data: Data {
         var source = self
         return .init(bytes: &source, count: MemoryLayout<Self>.size)

Sources/Confidence/EventSenderEngine.swift

@@ -123,7 +123,12 @@ final class EventSenderEngineImpl: EventSenderEngine {
     }
 
     func withSemaphore(callback: @escaping () async -> Void) async {
-        semaphore.wait()
+        await withCheckedContinuation { continuation in
+            DispatchQueue.global().async {
+                self.semaphore.wait()
+                continuation.resume()
+            }
+        }
         await callback()
         semaphore.signal()
     }

Sources/Confidence/EventStorage.swift

@@ -75,17 +75,20 @@ internal class EventStorageImpl: EventStorage {
             let decoder = JSONDecoder()
             let fileUrl = folderURL.appendingPathComponent(id)
             let data = try Data(contentsOf: fileUrl)
-            let dataString = String(decoding: data, as: UTF8.self)
-            return try dataString.components(separatedBy: "\n")
-                .filter { events in
-                    !events.isEmpty
-                }
-                .compactMap { eventString in
-                    guard let stringData = eventString.data(using: .utf8) else {
-                        return nil
+            if let dataString = String(data: data, encoding: .utf8) {
+                return try dataString.components(separatedBy: "\n")
+                    .filter { events in
+                        !events.isEmpty
                     }
-                    return try decoder.decode(ConfidenceEvent.self, from: stringData)
-                }
+                    .compactMap { eventString in
+                        guard let stringData = eventString.data(using: .utf8) else {
+                            return nil
+                        }
+                        return try decoder.decode(ConfidenceEvent.self, from: stringData)
+                    }
+            } else {
+                return []
+            }
         }
     }
 

Sources/Confidence/Http/NetworkClient.swift

@@ -134,10 +134,10 @@ extension NetworkClient {
                 do {
                     response.decodedError = try decoder.decode(HttpError.self, from: responseData)
                 } catch {
-                    let message = String(decoding: responseData, as: UTF8.self)
+                    let message = String(data: responseData, encoding: .utf8)
                     response.decodedError = HttpError(
                         code: httpURLResponse.statusCode,
-                        message: message,
+                        message: message ?? "{Error when decoding error message}",
                         details: []
                     )
                 }

Tests/ConfidenceProviderTests/ConfidenceProviderTest.swift

@@ -139,7 +139,7 @@ private class StorageMock: Storage {
     func save(data: Encodable) throws {
         try storageQueue.sync {
             let dataB = try JSONEncoder().encode(data)
-            self.data = String(decoding: dataB, as: UTF8.self)
+            self.data = try XCTUnwrap(String(data: dataB, encoding: .utf8))
 
             saveExpectation?.fulfill()
         }

Tests/ConfidenceTests/ConfidenceTest.swift

@@ -233,7 +233,7 @@ class ConfidenceTest: XCTestCase {
             .build()
 
         try await confidence.fetchAndActivate()
-        let value = try confidence.getValue(
+        let value = confidence.getValue(
             key: "flag.size",
             defaultValue: 0 as Int64)
 

Tests/ConfidenceTests/ConfidenceValueTests.swift

@@ -125,7 +125,7 @@ final class ConfidenceConfidenceValueTests: XCTestCase {
         let encoder = JSONEncoder()
         encoder.outputFormatting = .sortedKeys
         let data = try encoder.encode(value)
-        let resultString = try XCTUnwrap(String(decoding: data, as: UTF8.self))
+        let resultString = try XCTUnwrap(String(data: data, encoding: .utf8))
         let resultData = try XCTUnwrap(resultString.data(using: .utf8))
         let decodedValue = try JSONDecoder().decode(ConfidenceValue.self, from: resultData)
 

Tests/ConfidenceTests/FlagApplierWithRetriesTest.swift

@@ -99,7 +99,7 @@ class FlagApplierWithRetriesTest: XCTestCase {
         await applier.apply(flagName: "flag2", resolveToken: "token1")
         await applier.apply(flagName: "flag3", resolveToken: "token1")
 
-        await waitForExpectations(timeout: 1.0)
+        await fulfillment(of: [networkExpectation], timeout: 1.0)
 
         // Then cache data is not stored on to the disk
         // But stored in the local cache as sent
@@ -152,7 +152,7 @@ class FlagApplierWithRetriesTest: XCTestCase {
             metadata: metadata
         )
 
-        await waitForExpectations(timeout: 5.0)
+        await fulfillment(of: [storageExpectation, expectation], timeout: 1.0)
 
         // Then http client sends 5 apply flag batch request, containing 20 records each
         let request = try XCTUnwrap(httpClient.data?.first as? ApplyFlagsRequest)
@@ -184,7 +184,7 @@ class FlagApplierWithRetriesTest: XCTestCase {
             metadata: metadata
         )
 
-        await waitForExpectations(timeout: 5.0)
+        await fulfillment(of: [storageExpectation, expectation], timeout: 1.0)
 
         // Then http client sends 5 apply flag batch request, containing 20 records each
         let request = try XCTUnwrap(httpClient.data?.first as? ApplyFlagsRequest)
@@ -215,7 +215,7 @@ class FlagApplierWithRetriesTest: XCTestCase {
             metadata: metadata
         )
 
-        await waitForExpectations(timeout: 5.0)
+        await fulfillment(of: [storageExpectation, expectation], timeout: 1.0)
 
         // Then http client sends 5 apply flags batch request, containing 20 records each
         let request = try XCTUnwrap(partiallyFailingHttpClient.data?.first as? ApplyFlagsRequest)
@@ -254,7 +254,7 @@ class FlagApplierWithRetriesTest: XCTestCase {
         httpClient.testMode = .success
         await applier.apply(flagName: "flag2", resolveToken: "token1")
 
-        await waitForExpectations(timeout: 1.0)
+        await fulfillment(of: [networkExpectation], timeout: 1.0)
 
         // Then 3 post calls are issued (one offline, one batch apply containing 2 reconrds)
         XCTAssertEqual(httpClient.postCallCounter, 2)
@@ -298,7 +298,7 @@ class FlagApplierWithRetriesTest: XCTestCase {
         // With test mode .success
         offlineClient.testMode = .success
         await applier.apply(flagName: "flag2", resolveToken: "token1")
-        await waitForExpectations(timeout: 1.0)
+        await fulfillment(of: [networkExpectation, storageExpectation], timeout: 1.0)
 
         // Then both requests are marked as sent in cache data
         let cacheData = await cacheDataInteractor.cache
@@ -332,7 +332,7 @@ class FlagApplierWithRetriesTest: XCTestCase {
             metadata: metadata
         )
 
-        await waitForExpectations(timeout: 1.0)
+        await fulfillment(of: [storageExpectation, networkExpectation], timeout: 1.0)
 
         // Then storage has been cleaned
         let storedData = try prefilledStorage.load(defaultValue: CacheData.empty())
@@ -361,7 +361,7 @@ class FlagApplierWithRetriesTest: XCTestCase {
         // When 100 apply calls are issued
         // And all http client requests fails with .invalidResponse
         await hundredApplyCalls(applier: applier, sameToken: true)
-        await waitForExpectations(timeout: 1.0)
+        await fulfillment(of: [networkExpectation], timeout: 1.0)
 
         // Then strored data is empty
         let storedData: CacheData = try XCTUnwrap(prefilledStorage.load(defaultValue: CacheData.empty()))
@@ -471,7 +471,7 @@ class FlagApplierWithRetriesTest: XCTestCase {
         // And http client request fails with .invalidResponse
         await applier.apply(flagName: "flag1", resolveToken: "token1")
 
-        await waitForExpectations(timeout: 5.0)
+        await fulfillment(of: [networkExpectation], timeout: 1.0)
 
         // Then 2 resolve event records are stored on disk
         let storedData: CacheData = try XCTUnwrap(prefilledStorage.load(defaultValue: CacheData.empty()))
@@ -535,7 +535,7 @@ class FlagApplierWithRetriesTest: XCTestCase {
         // When 100 apply calls are issued
         // And all http client requests fails with .invalidResponse
         await hundredApplyCalls(applier: applier, sameToken: true)
-        await waitForExpectations(timeout: 1.0)
+        await fulfillment(of: [networkExpectation], timeout: 1.0)
 
         // Then 1 resolve event record is stored on disk
         // And 200 flag event records are stored on disk

Tests/ConfidenceTests/Helpers/StorageMock.swift

@@ -17,7 +17,7 @@ class StorageMock: Storage {
     func save(data: Encodable) throws {
         try storageQueue.sync {
             let dataB = try JSONEncoder().encode(data)
-            self.data = String(decoding: dataB, as: UTF8.self)
+            self.data = try XCTUnwrap(String(data: dataB, encoding: .utf8))
 
             saveExpectation?.fulfill()
         }