feat: mapfunction supports Iterable<Promise<T>>

src/Lazy/differenceBy.ts

@@ -1,3 +1,4 @@
+import { throwIfPromiseError } from "../_internal/error";
 import { isAsyncIterable, isIterable } from "../_internal/utils";
 import pipe from "../pipe";
 import pipe1 from "../pipe1";
@@ -13,7 +14,7 @@ function* sync<T>(
   iterable1: Iterable<T>,
   iterable2: Iterable<T>,
 ) {
-  const set = new Set(map(f, iterable1));
+  const set = new Set(map((a) => throwIfPromiseError(f(a)), iterable1));
 
   yield* pipe(
     iterable2,

src/Lazy/flatMap.ts

@@ -1,3 +1,4 @@
+import { throwIfPromiseError } from "../_internal/error";
 import { isAsyncIterable, isIterable } from "../_internal/utils";
 import type Awaited from "../types/Awaited";
 import type { DeepFlat, DeepFlatSync } from "../types/DeepFlat";
@@ -87,12 +88,12 @@ function flatMap<
 ): ReturnFlatMapType<A, B> | ((iterable: A) => ReturnFlatMapType<A, B>) {
   if (iterable === undefined) {
     return (iterable: A) => {
-      return flat(map(f, iterable as any)) as any;
+      return flatMap(f, iterable) as any;
     };
   }
 
   if (isIterable<IterableInfer<A>>(iterable)) {
-    return flat(map(f, iterable as any)) as any;
+    return flat(map((a) => throwIfPromiseError(f(a)), iterable)) as any;
   }
 
   if (isAsyncIterable<Awaited<IterableInfer<A>>>(iterable)) {

src/Lazy/intersectionBy.ts

@@ -1,3 +1,4 @@
+import { throwIfPromiseError } from "../_internal/error";
 import { isAsyncIterable, isIterable } from "../_internal/utils";
 import pipe from "../pipe";
 import pipe1 from "../pipe1";
@@ -13,7 +14,7 @@ function* sync<T>(
   iterable1: Iterable<T>,
   iterable2: Iterable<T>,
 ) {
-  const set = new Set(map(f, iterable1));
+  const set = new Set(map((a) => throwIfPromiseError(f(a)), iterable1));
 
   yield* pipe(
     iterable2,

src/Lazy/map.ts

@@ -1,5 +1,5 @@
 import { AsyncFunctionException } from "../_internal/error";
 import { isAsyncIterable, isIterable, isPromise } from "../_internal/utils";
 import type Awaited from "../types/Awaited";
 import type IterableInfer from "../types/IterableInfer";
 import type ReturnIterableIteratorType from "../types/ReturnIterableIteratorType";
@@ -20,14 +20,9 @@
         };
       }
 
-      const res = f(value);
-      if (isPromise(res)) {
-        throw new AsyncFunctionException();
-      }
-
       return {
         done: false,
-        value: res,
+        value: f(value),
       };
     },
     [Symbol.iterator]() {

src/Lazy/zipWith.ts

@@ -1,3 +1,4 @@
+import { throwIfPromiseError } from "../_internal/error";
 import { isAsyncIterable, isIterable } from "../_internal/utils";
 import map from "./map";
 import zip from "./zip";
@@ -44,7 +45,10 @@ function zipWith<A, B, C>(
   iterable2: Iterable<B> | AsyncIterable<B>,
 ): IterableIterator<C> | AsyncIterableIterator<C> {
   if (isIterable(iterable1) && isIterable(iterable2)) {
-    return map(([a, b]) => f(a, b), zip(iterable1, iterable2));
+    return map(
+      ([a, b]) => throwIfPromiseError(f(a, b)),
+      zip(iterable1, iterable2),
+    );
   }
   if (isIterable(iterable1) && isAsyncIterable(iterable2)) {
     return map(([a, b]) => f(a, b), zip(iterable1, iterable2));

src/_internal/error.ts

@@ -1,3 +1,5 @@
+import { isPromise } from "./utils";
+
 export class AsyncFunctionException extends Error {
   static MESSAGE = `'Iterable' can not used with async function.
 If you want to deal with async function, see: [toAsync](https://fxts.dev/docs/toAsync)`;
@@ -6,3 +8,11 @@ If you want to deal with async function, see: [toAsync](https://fxts.dev/docs/to
     super(message);
   }
 }
+
+export const throwIfPromiseError = <T>(a: Promise<T> | T): T => {
+  if (isPromise(a)) {
+    throw new AsyncFunctionException();
+  }
+
+  return a;
+};

src/every.ts

@@ -1,3 +1,4 @@
+import { throwIfPromiseError } from "./_internal/error";
 import { isAsyncIterable, isIterable } from "./_internal/utils";
 import map from "./Lazy/map";
 import takeUntil from "./Lazy/takeUntil";
@@ -56,7 +57,7 @@ function every<
 
   if (isIterable<IterableInfer<A>>(iterable)) {
     return pipe(
-      map(f, iterable),
+      map((a) => throwIfPromiseError(f(a)), iterable),
       takeUntil(not),
       (acc) =>
         reduce(

src/some.ts

@@ -1,3 +1,4 @@
+import { throwIfPromiseError } from "./_internal/error";
 import { isAsyncIterable, isIterable } from "./_internal/utils";
 import identity from "./identity";
 import map from "./Lazy/map";
@@ -76,7 +77,7 @@ function some<
 
   if (isIterable<IterableInfer<A>>(iterable)) {
     return pipe(
-      map(f, iterable),
+      map((a) => throwIfPromiseError(f(a)), iterable),
       takeUntil(identity),
       (acc) =>
         reduce(

test/Lazy/map.spec.ts

@@ -1,4 +1,3 @@
-import { AsyncFunctionException } from "../../src/_internal/error";
 import { fx, map, pipe, range, toArray, toAsync } from "../../src/index";
 import { Concurrent } from "../../src/Lazy/concurrent";
 import { generatorMock } from "../utils";
@@ -16,11 +15,6 @@ describe("map", function () {
       expect(acc).toEqual([11, 12, 13, 14, 15]);
     });
 
-    it("should throw an error when the callback is asynchronous", function () {
-      const res = () => [...map(add10Async, [1, 2, 3, 4, 5])];
-      expect(res).toThrowError(new AsyncFunctionException());
-    });
-
     it("should be able to be used as a curried function in the pipeline", function () {
       const res = pipe(
         [1, 2, 3, 4],
@@ -92,6 +86,18 @@ describe("map", function () {
 
       expect(res).toEqual(["1", "2", "3", "4"]);
     });
+    it("should be able to be used as a promise function", async function () {
+      const res1 = map(async (a) => a, [1, 2, 3, 4]);
+
+      expect(await Promise.all(res1)).toEqual([1, 2, 3, 4]);
+
+      const res2 = pipe(
+        [1, 2, 3, 4],
+        map(async (a) => a),
+      );
+
+      expect(await Promise.all(res2)).toEqual([1, 2, 3, 4]);
+    });
 
     it("should be able to be used as a chaining method in the `fx`", async function () {
       const res = await fx(toAsync([1, 2, 3, 4]))

type-check/Lazy/map.test.ts

@@ -30,6 +30,12 @@ const res10 = pipe(
   map(async (a) => a),
 );
 
+const res11 = map(async (a) => a, [1, 2, 3, 4]);
+const res12 = pipe(
+  [1, 2, 3, 4],
+  map(async (a) => a),
+);
+
 checks([
   check<typeof res1, IterableIterator<number>, Test.Pass>(),
   check<typeof res2, IterableIterator<string>, Test.Pass>(),
@@ -42,4 +48,7 @@ checks([
   check<typeof res8, IterableIterator<Promise<number>>, Test.Pass>(),
   check<typeof res9, AsyncIterableIterator<number>, Test.Pass>(),
   check<typeof res10, AsyncIterableIterator<number>, Test.Pass>(),
+
+  check<typeof res11, IterableIterator<Promise<number>>, Test.Pass>(),
+  check<typeof res12, IterableIterator<Promise<number>>, Test.Pass>(),
 ]);