From 3ab6fe5b4725bf5e29dbd069a7ed9a076a9890b6 Mon Sep 17 00:00:00 2001
From: Noah Treuhaft <noah.treuhaft@gmail.com>
Date: Fri, 28 Aug 2026 11:50:43 -0400
Subject: [PATCH] book/super-example: recover from panics in main.run

An unrecovered panic breaks the current page's Super instance and all
examples on the page along with it.
---
 book/super-example/main.go | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/book/super-example/main.go b/book/super-example/main.go
index aa714cab9a..c8f6f94c6c 100644
--- a/book/super-example/main.go
+++ b/book/super-example/main.go
@@ -6,7 +6,9 @@ import (
 	"bytes"
 	"context"
 	"errors"
+	"fmt"
 	"io"
+	"runtime/debug"
 	"slices"
 	"strings"
 	"syscall/js"
@@ -45,7 +47,12 @@ type chunk struct {
 var errInvalidInput = errors.New("only string or ReadableStream accept as input")
 
 func run(opts opts) wasm.Promise {
-	return wasm.NewPromise(func() (interface{}, error) {
+	return wasm.NewPromise(func() (v interface{}, err error) {
+		defer func() {
+			if r := recover(); r != nil {
+				err = fmt.Errorf("panic: %+v\n\n%s\n", r, debug.Stack())
+			}
+		}()
 		flowgraph, err := parser.ParseText(opts.Program)
 		if err != nil {
 			return "", err