Add asyncCompactMap (#14)

* Add asyncCompactMap
0xLeif · Sep 16, 2022 · d2ab6bf · d2ab6bf
1 parent 9be93fb
commit d2ab6bf
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diff --git a/Sources/Fork/Extensions/Array+ForkedArray.swift b/Sources/Fork/Extensions/Array+ForkedArray.swift
@@ -45,6 +45,13 @@ extension Array {
         try await fork(map: transform).output()
     }
 
+    /// Returns an array containing the results, that aren't nil, of mapping the given closure over the sequence’s elements.
+    public func asyncCompactMap<Output>(
+        _ transform: @escaping (Element) async throws -> Output?
+    ) async throws -> [Output] {
+        try await fork(map: transform).output().compactMap { $0 }
+    }
+
     /// Returns an array containing only the true results from the given closure over the sequence’s elements.
     public func asyncFilter(
         _ isIncluded: @escaping (Element) async throws -> Bool

diff --git a/Tests/ForkTests/ForkedArrayTests.swift b/Tests/ForkTests/ForkedArrayTests.swift
@@ -70,6 +70,19 @@ class ForkedArrayTests: XCTestCase {
         XCTAssertEqual(photos, photoNames)
     }
 
+    func testForkedArrayCompactMap_x() async throws {
+        let photoNames = [Int](0 ..< 100)
+        @Sendable func asyncFilter(number: Int) async -> String? {
+            guard number.isMultiple(of: 2) else { return nil }
+
+            return number.description
+        }
+
+        let compactedArray = try await photoNames.asyncCompactMap(asyncFilter(number:))
+
+        XCTAssertEqual(compactedArray.count, photoNames.count / 2)
+    }
+
     func testForkedArray_order() async throws {
         let photoNames = ["Hello", " ", "World", "!"]
         @Sendable func downloadPhoto(named: String) async -> String { named }