typescript(option): feat: added a mapAsync helper

Signed-off-by: prescientmoon <git@moonythm.dev>

typescript/option/src/helpers/external.ts

@@ -16,3 +16,4 @@ export * from './map'
 export * from './toArray'
 export * from './toNullable'
 export * from './withDefault'
+export * from './mapAsync'

typescript/option/src/helpers/mapAsync.ts

@@ -0,0 +1,18 @@
+import { Option, None, Some } from '../types'
+import { Mapper } from '../internalTypes'
+import { match } from './match'
+
+export const mapAsync = <T, U>(
+    mapper: Mapper<T, Promise<U>>,
+    option: Option<T>
+) => {
+    return match(
+        async value => {
+            const output = await mapper(value)
+
+            return Some(output)
+        },
+        Promise.resolve(None),
+        option
+    )
+}