Make fetch header compliant with the current spec (#1019)

1 files changed, 19 insertions, 0 deletions

diff --git a/js/util.ts b/js/util.ts
index 0c50acebb..0d2049842 100644
--- a/js/util.ts
+++ b/js/util.ts
@@ -125,3 +125,22 @@ export function deferred(): Deferred {
     reject: reject!
   };
 }
+
+/** Create a IterableIterator. */
+// @internal
+export class CreateIterableIterator<T> implements IterableIterator<T> {
+  private readonly _iterators: IterableIterator<T>;
+  readonly [Symbol.toStringTag] = "Iterator";
+
+  constructor(iterators: IterableIterator<T>) {
+    this._iterators = iterators;
+  }
+
+  [Symbol.iterator](): IterableIterator<T> {
+    return this;
+  }  
+
+  next(): IteratorResult<T> {
+    return this._iterators.next();
+  }
+}