In general, this should be fixed by adding a rate‑limiting middleware to the Express app so that the expensive SSR route cannot be invoked arbitrarily often. A standard way is to use a well‑known package like express-rate-limit, configure a reasonable window and maximum request count, and apply it to the relevant route (or globally, if appropriate).

For this file, the minimal change without altering existing behavior is:

1. Import express-rate-limit at the top of examples/vite-ssr-solidjs-streaming/server.js, alongside the existing imports.
2. Define a limiter (e.g., 100 requests per 15 minutes per IP, as in the example) after creating app.
3. Apply the limiter only to the expensive catch‑all route by adding it as middleware in app.use('/{*path}', limiter, async (req, res) => { ... }). This way, dev/prod logic, SSR behavior, and existing middleware order remain unchanged; only the number of requests per client to this route is constrained.

Concretely:

• Add import rateLimit from 'express-rate-limit' after the existing express import.
• After const app = express(), define const ssrLimiter = rateLimit({ windowMs: 15 * 60 * 1000, max: 100 }).
• Change the route at line 54 from app.use('/{*path}', async (req, res) => { ... }) to app.use('/{*path}', ssrLimiter, async (req, res) => { ... }).

To fix this, introduce a rate-limiting middleware using a well-known library such as express-rate-limit, and apply it specifically to the expensive route at app.use('/{*path}', ...) (or globally if desired). This controls how many requests a client can make in a time window, mitigating denial-of-service risks from repeated filesystem and SSR operations.

The best minimal-impact change within the shown file is:

1. Import express-rate-limit at the top of examples/vite-ssr-svelte-streaming/server.js.
2. Define a limiter instance (e.g., 100 requests per 15 minutes per IP) near where the Express app is created, after const app = express().
3. Apply this limiter to the expensive route by passing it as middleware before the existing async handler, i.e., change app.use('/{*path}', async (req, res) => { ... }) to app.use('/{*path}', limiter, async (req, res) => { ... }).

This preserves existing functionality and structure; only the addition of the middleware and its import are needed.

In general, never send raw exception messages or stack traces directly to the browser as HTML. For user-facing responses, either (a) send a generic error page/message that does not include user input, or (b) if you must include details, escape/encode the text appropriately (for example, HTML-escape it, or serve it with a safe content type like text/plain).

For this specific code, the safest and simplest change without altering core functionality is:

• Stop writing e.stack directly as HTML.
• Instead, respond with a generic error message to the client (for example, Internal Server Error) and continue logging the full stack trace to the server console.
• Optionally, if you still want to expose some detail (e.g., in dev), you can encode the stack trace before sending it or change the content type to text/plain. Since we should not change surrounding behavior more than necessary and avoid adding new configuration toggles, the minimal secure fix is to replace res.status(500).end(e.stack) with a generic constant string response such as res.status(500).end('Internal Server Error').

Concretely:

• In examples/vite-ssr-solidjs-streaming/server.js, within the catch (e) block around line 82, keep vite && vite.ssrFixStacktrace(e) and console.log(e.stack) as-is, but change the final response so it no longer includes e.stack. No new imports or helper functions are required.

In general, the fix is to avoid sending the stack trace (or detailed error object) to the client, and instead log it on the server while returning a generic error message and status code to the user. This preserves debuggability without exposing internal implementation details.

Specifically for this file, we should:

• Keep server-side logging (console.log or similar) of the full error/stack trace.
• Replace res.status(500).end(e.stack) with a generic message like res.status(500).end('Internal Server Error') (or localized/alternative wording) that does not depend on e or e.stack.
• Optionally slightly improve logging by logging both the error and its stack, but without changing behavior observed by the client.

All required functionality can be implemented within examples/vite-ssr-solidjs-streaming/server.js without new imports. The only change is in the catch block of the app.use('/{*path}', ...) handler around lines 82–86.

In general, to fix this class of issue you should avoid sending raw exception messages or stack traces directly in an HTML response. For production, it’s safer to send a generic error page or message that contains no user-controllable data. For development, if you really need to expose the error content to the browser, you must HTML‑escape (encode) it so that any <, >, &, quotes, etc. are rendered as text instead of being interpreted as HTML or JavaScript.

The best fix here without changing existing functionality too much is:

• In the catch block, keep logging the full stack trace to the server console (console.log(e.stack)).
• Change the HTTP response so that it no longer sends e.stack directly. Instead:
  • In production (isProd === true), send a generic error message (e.g., "Internal Server Error").
  • In non‑production, either:
    • send an HTML‑escaped version of e.stack, or
    • for maximum simplicity and safety, also send a generic message.
• Implement a small HTML-escaping helper within this file if you want to preserve error content in dev. This avoids adding new dependencies and keeps the change localized.

Concretely, in examples/vite-ssr-svelte-streaming/server.js:

• Add a simple escapeHtml helper function near the top of the file.
• Replace res.status(500).end(e.stack) with something like:
  • const msg = isProd ? 'Internal Server Error' : escapeHtml(String(e.stack || e));
  • res.status(500).set({ 'Content-Type': 'text/html; charset=utf-8' }).end(msg);
• Make sure the catch block doesn’t introduce any new tainted pathway (i.e., only escapes or discards exception content).

In general, the fix is to stop sending full stack traces to the client and instead send a generic error message while logging the stack trace on the server. The server logs retain the detail needed for debugging without exposing it over HTTP.

For this specific file, the best minimal change is inside the catch (e) block of the app.use('/{*path}', ...) handler. We should:

• Keep vite && vite.ssrFixStacktrace(e) as-is (it adjusts stack traces for server-side logging and debugging).
• Keep logging the error stack to the server console (or potentially improve logging later), but not include it in the HTTP response.
• Replace res.status(500).end(e.stack) with a response that sends a generic message such as "Internal Server Error" or "An error occurred" without any stack/implementation details.

No new imports or external libraries are strictly required. All changes are localized to the existing catch block in examples/vite-ssr-svelte-streaming/server.js, around lines 82–86.