deploy: 7e64238

Author: fizruk

app.wasm

@@ -5,15 +5,27 @@
 // value and drops the caret at the end. The update function knows the offset the
 // caret should have, and calls this once the patch has landed.
 //
-// The rAF is what waits for that patch: the update returns before miso has
-// touched the DOM, so setting the selection synchronously would set it on the
-// pre-rewrite text and be overwritten a frame later.
-globalThis.setEditorCaret = function (offset) {
-  requestAnimationFrame(function () {
+// Waiting for that patch is the whole difficulty. miso diffs inside an animation
+// frame of its own, queued after the one this call could take, and assigning
+// .value moves the caret to the end — so setting the selection a frame too early
+// is silently undone. Rather than guess the ordering, wait until the textarea
+// actually holds the text the caret offset refers to, then place it.
+//
+// The bound on retries keeps a mismatch (an edit that arrived meanwhile, say)
+// from spinning forever; giving up leaves the caret where the browser put it.
+globalThis.setEditorCaret = function (offset, expected) {
+  let tries = 0;
+  const place = function () {
     const el = document.querySelector("textarea.editor");
     if (!el) return;
+    if (el.value !== expected && tries < 10) {
+      tries++;
+      requestAnimationFrame(place);
+      return;
+    }
     const i = Math.max(0, Math.min(Number(offset) || 0, el.value.length));
     el.focus();
     el.setSelectionRange(i, i);
-  });
+  };
+  requestAnimationFrame(place);
 };