Fixing request proxy to send stream instead of loading body. It fix binaries file upload that use the proxy aswell

Author: Benoit Ngo

apps/front/package.json

@@ -6,7 +6,7 @@
     "generate": "nuxt generate",
     "preview": "nuxt preview",
     "postinstall": "nuxt prepare",
-    "lint": "eslint nuxt.config.ts --fix ; nuxi typecheck ; eslint ./src/"
+    "lint": "eslint nuxt.config.ts --fix ; nuxi typecheck && eslint ./src/"
   },
   "devDependencies": {
     "@nuxt/eslint-config": "^0.1.1",

apps/front/src/server/api/[...].ts

@@ -1,5 +1,11 @@
-import { defineEventHandler, H3Event, proxyRequest } from "h3";
-
+import {
+  defineEventHandler,
+  H3Event,
+  RequestHeaders,
+  getMethod,
+  getRequestHeaders,
+  sendProxy as _sendProxy,
+} from "h3";
 /**
  * Beware
  * Using the SSR, cookies are transmitted to the proxy BUT
@@ -25,6 +31,81 @@ import { defineEventHandler, H3Event, proxyRequest } from "h3";
 
 import logger from "~/utils/logger";
 
+/**
+ * This code override proxyRequest from h3
+ */
+
+/**
+ * start - this code is not exported from h3
+ */
+export interface ProxyOptions {
+  headers?: RequestHeaders | HeadersInit;
+  fetchOptions?: RequestInit;
+  fetch?: typeof fetch;
+  sendStream?: boolean;
+  cookieDomainRewrite?: string | Record<string, string>;
+  cookiePathRewrite?: string | Record<string, string>;
+  onResponse?: (event: H3Event, response: Response) => void;
+}
+
+const ignoredHeaders = new Set([
+  'transfer-encoding',
+  'connection',
+  'keep-alive',
+  'upgrade',
+  'expect',
+  'host',
+]);
+
+export function getProxyRequestHeaders(event: H3Event) {
+  const headers = Object.create(null);
+  const reqHeaders = getRequestHeaders(event);
+  // eslint-disable-next-line no-restricted-syntax
+  for (const name in reqHeaders) {
+    if (!ignoredHeaders.has(name)) {
+      headers[name] = reqHeaders[name];
+    }
+  }
+  return headers;
+}
+
+/**
+ * end - this code is not exported from h3
+ */
+
+/**
+ * This code override h3 default behavior:
+ * Instead of reading the body we send the body as the stream, allowing better memory usage + prevent utf8 decoding
+ * */
+async function proxyRequest(
+  event: H3Event,
+  target: string,
+  opts: ProxyOptions = {},
+) {
+  const method = getMethod(event);
+
+  // Headers
+  const headers = getProxyRequestHeaders(event);
+  if (opts.fetchOptions?.headers) {
+    Object.assign(headers, opts.fetchOptions.headers);
+  }
+  if (opts.headers) {
+    Object.assign(headers, opts.headers);
+  }
+  return _sendProxy(event, target, {
+    ...opts,
+    fetchOptions: {
+      headers,
+      method,
+      body: method !== "GET" && method !== "HEAD" ? event.node.req : undefined,
+      ...opts.fetchOptions,
+    } as RequestInit,
+  });
+}
+
+/**
+ * Here we use the proxy as a default request
+ */
 export default defineEventHandler(async (event: H3Event) => {
   const { API_URL } = useRuntimeConfig();
   const target = new URL(event.req.url as string, API_URL);
@@ -33,6 +114,7 @@ export default defineEventHandler(async (event: H3Event) => {
     headers: {
       host: target.host,
     },
+    sendStream: true,
     fetchOptions: {
       redirect: "manual",
     },