Send an html page with 500 responses (#10851)

bjorn3 · web-flow · commit 2d3f6dc0f801 · 2025-05-28T14:48:46.000Z
Otherwise the user will only see a blank page.
diff --git a/src/commands/serve.rs b/src/commands/serve.rs
@@ -445,10 +445,25 @@ impl ServeCommand {
                                     Ok(r) => Ok::<_, Infallible>(r),
                                     Err(e) => {
                                         eprintln!("error: {e:?}");
+                                        let error_html = "\
+<!doctype html>
+<html>
+<head>
+    <title>500 Internal Server Error</title>
+</head>
+<body>
+    <center>
+        <h1>500 Internal Server Error</h1>
+        <hr>
+        wasmtime
+    </center>
+</body>
+</html>";
                                         Ok(Response::builder()
                                             .status(StatusCode::INTERNAL_SERVER_ERROR)
+                                            .header("Content-Type", "text/html; charset=UTF-8")
                                             .body(
-                                                Full::new(bytes::Bytes::new())
+                                                Full::new(bytes::Bytes::from(error_html))
                                                     .map_err(to_errorcode)
                                                     .boxed(),
                                             )
