Added CurrentValuePublisher.combineLatest(_:)

Author: lukaskubanek

Sources/CombineExtensions/CurrentValuePublisher/CurrentValuePublisher+CombineLatest.swift

@@ -0,0 +1,30 @@
+import Combine
+
+extension CurrentValuePublisher {
+    
+    /// Returns a new `CurrentValuePublisher` that combines the current value and subsequent values
+    /// from this publisher with those from another `CurrentValuePublisher`.
+    ///
+    /// The returned publisher emits a tuple containing the latest values from both publishers
+    /// whenever the value of either publisher changes.
+    ///
+    /// - Parameter other: Another `CurrentValuePublisher` to combine with.
+    /// - Returns: A `CurrentValuePublisher` that emits tuples of the latest values from both
+    ///   publishers.
+    public func combineLatest<T>(
+        _ other: CurrentValuePublisher<T, Failure>
+    ) -> CurrentValuePublisher<(Output, T), Failure> {
+        switch (self.storage, other.storage) {
+        case (.constant, .constant):
+            return CurrentValuePublisher<(Output, T), Failure>(
+                value: (self.value, other.value)
+            )
+        default:
+            return CurrentValuePublisher<(Output, T), Failure>(
+                initial: (self.value, other.value),
+                upstream: Publishers.CombineLatest(self, other).dropFirst()
+            )
+        }
+    }
+    
+}

Tests/CombineExtensionsTests/CurrentValuePublisher/CurrentValuePublisherTests.swift

@@ -679,50 +679,50 @@ class CurrentValuePublisherTests: XCTestCase {
         XCTAssertEqual(values, [1, 4, 6, 7])
     }
 
-//    // ============================================================================ //
-//    // MARK: - CombineLatest Operator
-//    // ============================================================================ //
-//    
-//    func testCombineLatest_constants() {
-//        var cancellables = Set<AnyCancellable>()
-//        var values = [[Int]]()
-//        
-//        let publisher1 = CurrentValuePublisher<Int, Never>(value: 100)
-//        let publisher2 = CurrentValuePublisher<Int, Never>(value: 200)
-//        
-//        publisher1.combineLatest(publisher2)
-//            .sink { values.append([$0, $1]) }
-//            .store(in: &cancellables)
-//        
-//        XCTAssertEqual(values, [[100, 200]])
-//    }
-//    
-//    func testCombineLatest_subjects() {
-//        var cancellables = Set<AnyCancellable>()
-//        var values = [[Int]]()
-//        
-//        let subject1 = CurrentValueSubject<Int, Never>(100)
-//        let publisher1 = CurrentValuePublisher(subject1)
-//        
-//        let subject2 = CurrentValueSubject<Int, Never>(200)
-//        let publisher2 = CurrentValuePublisher(subject2)
-//        
-//        publisher1.combineLatest(publisher2)
-//            .sink { values.append([$0, $1]) }
-//            .store(in: &cancellables)
-//        
-//        XCTAssertEqual(values, [[100, 200]])
-//        
-//        subject1.send(101)
-//        XCTAssertEqual(values, [[100, 200], [101, 200]])
-//        
-//        subject1.send(102)
-//        XCTAssertEqual(values, [[100, 200], [101, 200], [102, 200]])
-//        
-//        subject2.send(201)
-//        XCTAssertEqual(values, [[100, 200], [101, 200], [102, 200], [102, 201]])
-//    }
-//    
+    // ============================================================================ //
+    // MARK: - CombineLatest Operator
+    // ============================================================================ //
+    
+    func testCombineLatest_constants() {
+        var cancellables = Set<AnyCancellable>()
+        var values = [[Int]]()
+        
+        let publisher1 = CurrentValuePublisher<Int, Never>(value: 100)
+        let publisher2 = CurrentValuePublisher<Int, Never>(value: 200)
+        
+        publisher1.combineLatest(publisher2)
+            .sink { values.append([$0, $1]) }
+            .store(in: &cancellables)
+        
+        XCTAssertEqual(values, [[100, 200]])
+    }
+    
+    func testCombineLatest_subjects() {
+        var cancellables = Set<AnyCancellable>()
+        var values = [[Int]]()
+        
+        let subject1 = CurrentValueSubject<Int, Never>(100)
+        let publisher1 = CurrentValuePublisher(subject1)
+        
+        let subject2 = CurrentValueSubject<Int, Never>(200)
+        let publisher2 = CurrentValuePublisher(subject2)
+        
+        publisher1.combineLatest(publisher2)
+            .sink { values.append([$0, $1]) }
+            .store(in: &cancellables)
+        
+        XCTAssertEqual(values, [[100, 200]])
+        
+        subject1.send(101)
+        XCTAssertEqual(values, [[100, 200], [101, 200]])
+        
+        subject1.send(102)
+        XCTAssertEqual(values, [[100, 200], [101, 200], [102, 200]])
+        
+        subject2.send(201)
+        XCTAssertEqual(values, [[100, 200], [101, 200], [102, 200], [102, 201]])
+    }
+    
 //    // ============================================================================ //
 //    // MARK: - Boolean Operators
 //    // ============================================================================ //