feat(fetch): accept async iterables for body (#26882)

Reland of #24623, but with a fix for `String` objects.

Co-authored-by: crowlkats <crowlkats@toaxl.com>

2 files changed, 41 insertions, 1 deletions

diff --git a/tests/unit/fetch_test.ts b/tests/unit/fetch_test.ts
index 3ae96746a..6d3fd8cc1 100644
--- a/tests/unit/fetch_test.ts
+++ b/tests/unit/fetch_test.ts
@@ -2119,3 +2119,30 @@ Deno.test(
     await server;
   },
 );
+
+Deno.test("fetch async iterable", async () => {
+  const iterable = (async function* () {
+    yield new Uint8Array([1, 2, 3, 4, 5]);
+    yield new Uint8Array([6, 7, 8, 9, 10]);
+  })();
+  const res = new Response(iterable);
+  const actual = await res.bytes();
+  const expected = new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
+  assertEquals(actual, expected);
+});
+
+Deno.test("fetch iterable", async () => {
+  const iterable = (function* () {
+    yield new Uint8Array([1, 2, 3, 4, 5]);
+    yield new Uint8Array([6, 7, 8, 9, 10]);
+  })();
+  const res = new Response(iterable);
+  const actual = await res.bytes();
+  const expected = new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
+  assertEquals(actual, expected);
+});
+
+Deno.test("fetch string object", async () => {
+  const res = new Response(Object("hello"));
+  assertEquals(await res.text(), "hello");
+});
diff --git a/tests/unit/streams_test.ts b/tests/unit/streams_test.ts
index b866fa7d5..73f9a6095 100644
--- a/tests/unit/streams_test.ts
+++ b/tests/unit/streams_test.ts
@@ -1,5 +1,10 @@
 // Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
-import { assertEquals, assertRejects, fail } from "./test_util.ts";
+import {
+  assertEquals,
+  assertRejects,
+  assertThrows,
+  fail,
+} from "./test_util.ts";
 
 const {
   core,
@@ -533,3 +538,11 @@ Deno.test(async function decompressionStreamInvalidGzipStillReported() {
     "corrupt gzip stream does not have a matching checksum",
   );
 });
+
+Deno.test(function readableStreamFromWithStringThrows() {
+  assertThrows(
+    () => ReadableStream.from("string"),
+    TypeError,
+    "Failed to execute 'ReadableStream.from': Argument 1 can not be converted to async iterable.",
+  );
+});