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>

1 files changed, 14 insertions, 1 deletions

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.",
+  );
+});