Support streams in response.formData() & request.formData, introduce Bun.readableStreamToFormData() (#3697)

* codegen

* FormData.from

* Fixes #3225

* Introduce `Bun.readableStreamToFormData`

* Update bun.d.ts

* Add examples

* add

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/src/js/builtins/ReadableStream.ts b/src/js/builtins/ReadableStream.ts
index 5a5b7e119..419a8e696 100644
--- a/src/js/builtins/ReadableStream.ts
+++ b/src/js/builtins/ReadableStream.ts
@@ -149,6 +149,16 @@ export function readableStreamToArrayBuffer(stream: ReadableStream<ArrayBuffer>)
 }
 
 $linkTimeConstant;
+export function readableStreamToFormData(
+  stream: ReadableStream<ArrayBuffer>,
+  contentType: string | ArrayBuffer | ArrayBufferView,
+): Promise<FormData> {
+  return Bun.readableStreamToBlob(stream).then(blob => {
+    return FormData.from(blob, contentType);
+  });
+}
+
+$linkTimeConstant;
 export function readableStreamToJSON(stream: ReadableStream): unknown {
   return Bun.readableStreamToText(stream).$then(globalThis.JSON.parse);
 }