From https://once.com/writebook

app/javascript/controllers/autoselect_controller.js

@@ -0,0 +1,13 @@
+import { Controller } from "@hotwired/stimulus"
+
+export default class extends Controller {
+  connect() {
+    if (this.autoselect) {
+      this.element.select()
+    }
+  }
+
+  get autoselect() {
+    return this.element.autofocus
+  }
+}