fix: handle multiple "Set-Cookie" headers in unstable_vitePlugin dev

.changeset/silent-rice-march.md

@@ -0,0 +1,5 @@
+---
+"@remix-run/dev": patch
+---
+
+Handle multiple "Set-Cookie" headers in Vite dev server

contributors.yml

@@ -406,6 +406,7 @@
 - ngtrthinh169TPC
 - ni554n
 - nicholaschiang
+- nickprinsloo
 - nicksrandall
 - nickytonline
 - niconiahi

integration/vite-dev-test.ts

@@ -77,6 +77,54 @@ test.describe("Vite dev", () => {
             );
           }
         `,
+        "app/routes/set-cookies.tsx": js`
+          import { LoaderFunction } from "@remix-run/node";
+
+          export const loader: LoaderFunction = () => {
+            const headers = new Headers();
+
+            headers.append(
+              "Set-Cookie",
+              "first=one; Domain=localhost; Path=/; SameSite=Lax"
+            );
+
+            headers.append(
+              "Set-Cookie",
+              "second=two; Domain=localhost; Path=/; SameSite=Lax"
+            );
+
+            headers.append(
+              "Set-Cookie",
+              "third=three; Domain=localhost; Path=/; SameSite=Lax"
+            );
+
+            headers.set("location", "http://localhost:${devPort}/get-cookies");
+
+            const response = new Response(null, {
+              headers,
+              status: 302,
+            });
+
+            return response;
+          };
+        `,
+        "app/routes/get-cookies.tsx": js`
+          import { json, LoaderFunctionArgs } from "@remix-run/node";
+          import { useLoaderData } from "@remix-run/react"
+
+          export const loader = ({ request }: LoaderFunctionArgs) => json({cookies: request.headers.get("Cookie")});
+
+          export default function IndexRoute() {
+            const { cookies } = useLoaderData<typeof loader>();
+
+            return (
+              <div id="get-cookies">
+                <h2 data-title>Get Cookies</h2>
+                <p data-cookies>{cookies}</p>
+              </div>
+            );
+          }
+        `,
       },
     });
 
@@ -141,6 +189,19 @@ test.describe("Vite dev", () => {
     await expect(hmrStatus).toHaveText("HMR updated: yes");
     await expect(input).toHaveValue("stateful");
   });
+
+  test("handles multiple set-cookie headers", async ({ page }) => {
+    await page.goto(`http://localhost:${devPort}/set-cookies`, {
+      waitUntil: "networkidle",
+    });
+
+    // Ensure we redirected
+    expect(new URL(page.url()).pathname).toBe("/get-cookies");
+
+    await expect(page.locator("#get-cookies [data-cookies]")).toHaveText(
+      "first=one; second=two; third=three"
+    );
+  });
 });
 
 let bufferize = (stream: Readable): (() => string) => {

packages/remix-dev/vite/node/adapter.ts

@@ -167,16 +167,24 @@ function createRequest(req: IncomingMessage): Request {
   return new NodeRequest(url.href, init);
 }
 
+// Adapted from more recent version of `handleNodeResponse`:
+// https://github.com/solidjs/solid-start/blob/7398163869b489cce503c167e284891cf51a6613/packages/start/node/fetch.js#L162-L185
 async function handleNodeResponse(webRes: Response, res: ServerResponse) {
   res.statusCode = webRes.status;
   res.statusMessage = webRes.statusText;
 
+  let cookiesStrings = [];
+
   for (let [name, value] of webRes.headers) {
     if (name === "set-cookie") {
-      res.setHeader(name, splitCookiesString(value));
+      cookiesStrings.push(...splitCookiesString(value));
     } else res.setHeader(name, value);
   }
 
+  if (cookiesStrings.length) {
+    res.setHeader("set-cookie", cookiesStrings);
+  }
+
   if (webRes.body) {
     let readable = Readable.from(webRes.body);
     readable.pipe(res);