[fix] File upload

packages/waku/src/lib/renderers/rsc-renderer.ts

@@ -9,9 +9,9 @@ import type {
 } from '../../server.js';
 import type { ResolvedConfig } from '../config.js';
 import { filePathToFileURL } from '../utils/path.js';
-import { parseFormData } from '../utils/form.js';
-import { streamToString } from '../utils/stream.js';
+import { streamToArrayBuffer } from '../utils/stream.js';
 import { decodeActionId } from '../renderers/utils.js';
+import { bufferToString, parseFormData } from '../utils/buffer.js';
 
 export const SERVER_MODULE_MAP = {
   'rsdw-server': 'react-server-dom-webpack/server.edge',
@@ -194,15 +194,16 @@ export async function renderRsc(
 
   let decodedBody: unknown | undefined = args.decodedBody;
   if (body) {
-    const bodyStr = await streamToString(body);
+    const bodyBuf = await streamToArrayBuffer(body);
     if (
       typeof contentType === 'string' &&
       contentType.startsWith('multipart/form-data')
     ) {
       // XXX This doesn't support streaming unlike busboy
-      const formData = parseFormData(bodyStr, contentType);
+      const formData = await parseFormData(bodyBuf, contentType);
       decodedBody = await decodeReply(formData, serverBundlerConfig);
-    } else if (bodyStr) {
+    } else if (bodyBuf.byteLength > 0) {
+      const bodyStr = bufferToString(bodyBuf);
       decodedBody = await decodeReply(bodyStr, serverBundlerConfig);
     }
   }

packages/waku/src/lib/utils/buffer.ts

@@ -0,0 +1,16 @@
+export const parseFormData = async (
+  buffer: ArrayBuffer,
+  contentType: string,
+): Promise<FormData> => {
+  const response = new Response(buffer, {
+    headers: {
+      'content-type': contentType,
+    },
+  });
+  return response.formData();
+};
+
+export const bufferToString = (buffer: ArrayBuffer): string => {
+  const enc = new TextDecoder();
+  return enc.decode(buffer);
+};

packages/waku/src/lib/utils/stream.ts

@@ -11,6 +11,32 @@ export const concatUint8Arrays = (arrs: Uint8Array[]): Uint8Array => {
   return array;
 };
 
+// FIXME remove the two loops if possible, if it is more efficient
+export const streamToArrayBuffer = async (stream: ReadableStream) => {
+  const reader = stream.getReader();
+  const chunks = [];
+  let totalSize = 0;
+  let done = false;
+  let value: Uint8Array | undefined;
+
+  do {
+    ({ done, value } = await reader.read());
+    if (!done && value) {
+      chunks.push(value);
+      totalSize += value.length;
+    }
+  } while (!done);
+
+  const result = new Uint8Array(totalSize);
+  let offset = 0;
+  for (const chunk of chunks) {
+    result.set(chunk, offset);
+    offset += chunk.length;
+  }
+
+  return result.buffer;
+};
+
 export const streamToString = async (
   stream: ReadableStream,
 ): Promise<string> => {