Improve unit tests reliability (#3430)

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Task/Issue URL:
https://app.asana.com/0/414709148257752/1208526755021935/f
Tech Design URL:
CC:

**Description**:

Improve reliability of test suite.

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**Steps to test this PR**:

Validate unit test changes and whether refactoring had any impact on
actual code and production flows.

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**Definition of Done (Internal Only)**:

* [ ] Does this PR satisfy our [Definition of
Done](https://app.asana.com/0/1202500774821704/1207634633537039/f)?


---
###### Internal references:
[Software Engineering
Expectations](https://app.asana.com/0/59792373528535/199064865822552)
[Technical Design
Template](https://app.asana.com/0/59792373528535/184709971311943)

Core/DailyPixel.swift

@@ -18,6 +18,7 @@
 //
 
 import Foundation
+import Persistence
 
 /// A variant of pixel that is fired at most once per day.
 ///
@@ -52,6 +53,8 @@ public final class DailyPixel {
                             error: Swift.Error? = nil,
                             withAdditionalParameters params: [String: String] = [:],
                             includedParameters: [Pixel.QueryParameters] = [.appVersion],
+                            pixelFiring: PixelFiring.Type = Pixel.self,
+                            dailyPixelStore: KeyValueStoring = DailyPixel.storage,
                             onComplete: @escaping (Swift.Error?) -> Void = { _ in }) {
         var key: String = pixel.name
 
@@ -61,13 +64,13 @@ public final class DailyPixel {
             key.append(":\(createSortedStringOfValues(from: errorParams))")
         }
 
-        if !hasBeenFiredToday(forKey: key, dailyPixelStorage: storage) {
-            Pixel.fire(pixel: pixel,
-                       error: error,
-                       includedParameters: includedParameters,
-                       withAdditionalParameters: params,
-                       onComplete: onComplete)
-            updatePixelLastFireDate(forKey: key)
+        if !hasBeenFiredToday(forKey: key, dailyPixelStore: dailyPixelStore) {
+            pixelFiring.fire(pixel: pixel,
+                             error: error,
+                             includedParameters: includedParameters,
+                             withAdditionalParameters: params,
+                             onComplete: onComplete)
+            updatePixelLastFireDate(forKey: key, dailyPixelStore: dailyPixelStore)
         } else {
             onComplete(Error.alreadyFired)
         }
@@ -80,12 +83,14 @@ public final class DailyPixel {
                                          error: Swift.Error? = nil,
                                          withAdditionalParameters params: [String: String] = [:],
                                          includedParameters: [Pixel.QueryParameters] = [.appVersion],
+                                         pixelFiring: PixelFiring.Type = Pixel.self,
+                                         dailyPixelStore: KeyValueStoring = DailyPixel.storage,
                                          onDailyComplete: @escaping (Swift.Error?) -> Void = { _ in },
                                          onCountComplete: @escaping (Swift.Error?) -> Void = { _ in }) {
         let key: String = pixel.name
 
-        if !hasBeenFiredToday(forKey: key, dailyPixelStorage: storage) {
-            Pixel.fire(
+        if !hasBeenFiredToday(forKey: key, dailyPixelStore: dailyPixelStore) {
+            pixelFiring.fire(
                 pixelNamed: pixel.name + "_d",
                 withAdditionalParameters: params,
                 includedParameters: includedParameters,
@@ -94,25 +99,25 @@ public final class DailyPixel {
         } else {
             onDailyComplete(Error.alreadyFired)
         }
-        updatePixelLastFireDate(forKey: key)
+        updatePixelLastFireDate(forKey: key, dailyPixelStore: dailyPixelStore)
         var newParams = params
         if let error {
             newParams.appendErrorPixelParams(error: error)
         }
-        Pixel.fire(
+        pixelFiring.fire(
             pixelNamed: pixel.name + "_c",
             withAdditionalParameters: newParams,
             includedParameters: includedParameters,
             onComplete: onCountComplete
         )
     }
 
-    private static func updatePixelLastFireDate(forKey key: String) {
-        storage.set(Date(), forKey: key)
+    private static func updatePixelLastFireDate(forKey key: String, dailyPixelStore: KeyValueStoring) {
+        dailyPixelStore.set(Date(), forKey: key)
     }
 
-    private static func hasBeenFiredToday(forKey key: String, dailyPixelStorage: UserDefaults) -> Bool {
-        if let lastFireDate = dailyPixelStorage.object(forKey: key) as? Date {
+    private static func hasBeenFiredToday(forKey key: String, dailyPixelStore: KeyValueStoring) -> Bool {
+        if let lastFireDate = dailyPixelStore.object(forKey: key) as? Date {
             return Date().isSameDay(lastFireDate)
         }
         return false

Core/PixelFiring.swift

@@ -27,24 +27,46 @@ public protocol PixelFiring {
                      includedParameters: [Pixel.QueryParameters],
                      onComplete: @escaping (Error?) -> Void)
 
+    static func fire(pixel: Pixel.Event,
+                     error: Error?,
+                     includedParameters: [Pixel.QueryParameters],
+                     withAdditionalParameters params: [String: String],
+                     onComplete: @escaping (Error?) -> Void)
+
     static func fire(_ pixel: Pixel.Event,
                      withAdditionalParameters params: [String: String])
+
+    static func fire(pixelNamed pixelName: String,
+                     withAdditionalParameters params: [String: String],
+                     includedParameters: [Pixel.QueryParameters],
+                     onComplete: @escaping (Error?) -> Void)
 }
 
 extension Pixel: PixelFiring {
     public static func fire(_ pixel: Pixel.Event,
                             withAdditionalParameters params: [String: String],
                             includedParameters: [Pixel.QueryParameters],
                             onComplete: @escaping (Error?) -> Void) {
-        
-        Pixel.fire(pixel: pixel,
+
+        Self.fire(pixel: pixel,
                    withAdditionalParameters: params,
                    includedParameters: includedParameters,
                    onComplete: onComplete)
     }
 
     public static func fire(_ pixel: Pixel.Event,
                             withAdditionalParameters params: [String: String]) {
-        Pixel.fire(pixel: pixel, withAdditionalParameters: params)
+        Self.fire(pixel: pixel, withAdditionalParameters: params)
+    }
+
+    public static func fire(pixelNamed pixelName: String,
+                            withAdditionalParameters params: [String: String],
+                            includedParameters: [Pixel.QueryParameters],
+                            onComplete: @escaping (Error?) -> Void) {
+        Self.fire(pixelNamed: pixelName,
+                  withAdditionalParameters: params,
+                  allowedQueryReservedCharacters: nil,
+                  includedParameters: includedParameters,
+                  onComplete: onComplete)
     }
 }

DuckDuckGoTests/AdAttributionPixelReporterTests.swift

@@ -44,7 +44,7 @@ final class AdAttributionPixelReporterTests: XCTestCase {
 
         let result = await sut.reportAttributionIfNeeded()
 
-        XCTAssertEqual(PixelFiringMock.lastPixel, .appleAdAttribution)
+        XCTAssertEqual(PixelFiringMock.lastPixelName, Pixel.Event.appleAdAttribution.name)
         XCTAssertTrue(result)
     }
 
@@ -55,7 +55,7 @@ final class AdAttributionPixelReporterTests: XCTestCase {
         await fetcherStorage.markAttributionReportSuccessful()
         let result = await sut.reportAttributionIfNeeded()
 
-        XCTAssertNil(PixelFiringMock.lastPixel)
+        XCTAssertNil(PixelFiringMock.lastPixelName)
         XCTAssertFalse(result)
     }
 
@@ -65,7 +65,7 @@ final class AdAttributionPixelReporterTests: XCTestCase {
 
         let result = await sut.reportAttributionIfNeeded()
 
-        XCTAssertEqual(PixelFiringMock.lastPixel?.name, "m_apple-ad-attribution")
+        XCTAssertEqual(PixelFiringMock.lastPixelName, "m_apple-ad-attribution")
         XCTAssertTrue(result)
     }
 
@@ -130,7 +130,7 @@ final class AdAttributionPixelReporterTests: XCTestCase {
 
         let result = await sut.reportAttributionIfNeeded()
 
-        XCTAssertNil(PixelFiringMock.lastPixel)
+        XCTAssertNil(PixelFiringMock.lastPixelName)
         XCTAssertTrue(fetcherStorage.wasAttributionReportSuccessful)
         XCTAssertTrue(result)
     }
@@ -141,7 +141,7 @@ final class AdAttributionPixelReporterTests: XCTestCase {
 
         let result = await sut.reportAttributionIfNeeded()
 
-        XCTAssertNil(PixelFiringMock.lastPixel)
+        XCTAssertNil(PixelFiringMock.lastPixelName)
         XCTAssertFalse(fetcherStorage.wasAttributionReportSuccessful)
         XCTAssertFalse(result)
     }