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, 26 insertions, 0 deletions

diff --git a/ext/webidl/internal.d.ts b/ext/webidl/internal.d.ts
index 1ce45463e..375d548d3 100644
--- a/ext/webidl/internal.d.ts
+++ b/ext/webidl/internal.d.ts
@@ -439,6 +439,27 @@ declare module "ext:deno_webidl/00_webidl.js" {
   ) => T[];
 
   /**
+   * Create a converter that converts an async iterable of the inner type.
+   */
+  function createAsyncIterableConverter<V, T>(
+    converter: (
+      v: V,
+      prefix?: string,
+      context?: string,
+      opts?: any,
+    ) => T,
+  ): (
+    v: any,
+    prefix?: string,
+    context?: string,
+    opts?: any,
+  ) => ConvertedAsyncIterable<V, T>;
+
+  interface ConvertedAsyncIterable<V, T> extends AsyncIterableIterator<T> {
+    value: V;
+  }
+
+  /**
    * Create a converter that converts a Promise of the inner type.
    */
   function createPromiseConverter<T>(
@@ -559,4 +580,9 @@ declare module "ext:deno_webidl/00_webidl.js" {
     | "Symbol"
     | "BigInt"
     | "Object";
+
+  /**
+   * Check whether a value is an async iterable.
+   */
+  function isAsyncIterable(v: any): boolean;
 }