fix(kanban): fail closed on persistence errors

req: sync/015

examples/kanban/static/command-log.js

@@ -85,10 +85,21 @@ async function appendReorder(database, wire) {
   };
   meta.put(actor, "actor");
   meta.put(causal, "causal");
-  commands.add(command);
-  const count = await result(commands.count());
-  await done;
-  return { command, count };
+  const append = result(commands.add(command));
+  const counted = result(commands.count());
+  const completion = done.then(
+    () => null,
+    (error) => error,
+  );
+  try {
+    const [, count] = await Promise.all([append, counted]);
+    const transactionError = await completion;
+    if (transactionError) throw transactionError;
+    return { command, count };
+  } catch (error) {
+    await completion;
+    throw error;
+  }
 }
 
 async function storedCommands(database) {
@@ -122,9 +133,12 @@ async function project(root, wasmHandler, command) {
 }
 
 function report(root, stage, error) {
+  const code = error && typeof error.name === "string" ? error.name : "Error";
   const message = error instanceof Error ? error.message : String(error);
   root.setAttribute("data-kanban-command-error", `${stage}: ${message}`);
-  root.dispatchEvent(new CustomEvent("kanban:command-error", { detail: { stage, message } }));
+  root.setAttribute("data-kanban-command-error-stage", stage);
+  root.setAttribute("data-kanban-command-error-code", code);
+  root.dispatchEvent(new CustomEvent("kanban:command-error", { detail: { stage, code, message } }));
 }
 
 function announce(root, message) {