Merge pull request #15 from mtj0928/optional-support

Optional Support

Author: mtj0928

Sources/AsyncOperations/Optional/Optional+asyncMap.swift

@@ -0,0 +1,23 @@
+extension Optional {
+    /// An async function of `map`.
+    /// - Parameter transform: A similar closure with `map`'s one, but it's async.
+    /// - Returns: A transformed optional.
+    public func asyncMap<T>(_ transform: (Wrapped) async throws -> T) async rethrows -> T? {
+        guard let value = self else {
+            return nil
+        }
+
+        return try await transform(value)
+    }
+
+    /// An async function of `flatMap`.
+    /// - Parameter transform: A similar closure with `flatMap`'s one, but it's async.
+    /// - Returns: A transformed optional.
+    public func asyncFlatMap<T>(_ transform: (Wrapped) async throws -> T?) async rethrows -> T? {
+        guard let value = self else {
+            return nil
+        }
+
+        return try await transform(value)
+    }
+}

Tests/AsyncOperationsTests/Optional/OptionalAsyncMap.swift

@@ -0,0 +1,44 @@
+import Testing
+import AsyncOperations
+
+struct OptionalAsyncMap {
+    @Test
+    func asyncMap() async throws {
+        let nonSendable: NonSendable? = NonSendable()
+        let result = await nonSendable.asyncMap { $0.number + 1 }
+        #expect(result == 1)
+    }
+
+    @Test
+    func asyncMapForNilCase() async throws {
+        let nonSendable: NonSendable? = nil
+        let result = await nonSendable.asyncMap { $0.number + 1 }
+        #expect(result == nil)
+    }
+
+    @Test
+    func asyncFlatMap() async throws {
+        let nonSendable: NonSendable? = NonSendable()
+        let result = await nonSendable.asyncFlatMap { $0.number + 1 }
+        #expect(result == 1)
+    }
+
+    @Test
+    func asyncFlatMapForNilCase() async throws {
+        let nonSendable: NonSendable? = nil
+        let result = await nonSendable.asyncFlatMap { $0.number + 1 }
+        #expect(result == nil)
+    }
+
+    @Test
+    func asyncFlatMapForNilNilCase() async throws {
+        let nonSendable: NonSendable? = NonSendable()
+        let result: Int? = await nonSendable.asyncFlatMap { _ in nil }
+        #expect(result == nil)
+    }
+}
+
+
+private class NonSendable {
+    var number = 0
+}