Tests: added tests for ClockType (#3029)

Sources/Misc/DateAndTime/Clock.swift

@@ -41,4 +41,12 @@ extension ClockType {
         }
     }
 
+    func durationSince(_ date: Date) -> TimeInterval {
+        if #available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.2, *) {
+            return date.distance(to: self.now)
+        } else {
+            return date.timeIntervalSince(self.now)
+        }
+    }
+
 }

Tests/UnitTests/Misc/ClockTests.swift

@@ -0,0 +1,57 @@
+//
+//  Copyright RevenueCat Inc. All Rights Reserved.
+//
+//  Licensed under the MIT License (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      https://opensource.org/licenses/MIT
+//
+//  ClockTests.swift
+//
+//  Created by Nacho Soto on 8/16/23.
+
+import Nimble
+@testable import RevenueCat
+import XCTest
+
+class ClockTests: TestCase {
+
+    private var startDate: Date!
+    private var startTime: DispatchTime!
+    private var clock: TestClock!
+
+    override func setUp() {
+        super.setUp()
+
+        self.startDate = Date()
+        self.startTime = .now()
+
+        self.clock = .init(now: self.startDate, currentTime: self.startTime)
+    }
+
+    func testDurationSinceDispatchTimeWithNoTime() {
+        expect(self.clock.durationSince(self.startTime)).to(beCloseTo(0))
+    }
+
+    func testDurationSinceDispatchTime() {
+        self.clock.advance(by: .seconds(5))
+        expect(self.clock.durationSince(self.startTime)).to(beCloseTo(5))
+
+        self.clock.advance(by: .seconds(-10))
+        expect(self.clock.durationSince(self.startTime)).to(beCloseTo(-5))
+    }
+
+    func testDurationSinceDateWithNoTime() {
+        expect(self.clock.durationSince(self.startDate)).to(beCloseTo(0))
+    }
+
+    func testDurationSinceDate() {
+        self.clock.advance(by: .seconds(5))
+        expect(self.clock.durationSince(self.startDate)).to(beCloseTo(5))
+
+        self.clock.advance(by: .seconds(-10))
+        expect(self.clock.durationSince(self.startDate)).to(beCloseTo(-5))
+    }
+
+}