feat: make assistant-last-signer check signing-group aware

packages/lib/utils/recipients.test.ts

@@ -51,6 +51,24 @@ describe('recipient signing order helpers', () => {
     ]);
   });
 
+  it('detects an assistant anywhere in the last signing step (groups)', () => {
+    expect(
+      isAssistantLastSigner([
+        { role: RecipientRole.SIGNER, signingOrder: 1 },
+        { role: RecipientRole.ASSISTANT, signingOrder: 2 },
+        { role: RecipientRole.SIGNER, signingOrder: 2 },
+      ]),
+    ).toBe(true);
+
+    expect(
+      isAssistantLastSigner([
+        { role: RecipientRole.ASSISTANT, signingOrder: 1 },
+        { role: RecipientRole.SIGNER, signingOrder: 1 },
+        { role: RecipientRole.SIGNER, signingOrder: 2 },
+      ]),
+    ).toBe(false);
+  });
+
   it('checks whether the last non-CC recipient is an assistant', () => {
     expect(
       isAssistantLastSigner([

packages/lib/utils/recipients.ts

@@ -22,11 +22,32 @@ export const isCcRecipient = (recipient: Pick<Recipient, 'role'>) => {
   return recipient.role === RecipientRole.CC;
 };
 
-export const isAssistantLastSigner = (recipients: Pick<Recipient, 'role'>[]) => {
+/**
+ * Whether an assistant sits in the last signing step (nobody after them to assist).
+ *
+ * Falls back to a positional check when no recipient carries a signing order.
+ */
+export const isAssistantLastSigner = (
+  recipients: Array<Pick<Recipient, 'role'> & { signingOrder?: number | null }>,
+) => {
   const nonCcRecipients = recipients.filter((recipient) => !isCcRecipient(recipient));
-  const lastNonCcRecipient = nonCcRecipients[nonCcRecipients.length - 1];
 
-  return lastNonCcRecipient?.role === RecipientRole.ASSISTANT;
+  if (nonCcRecipients.length === 0) {
+    return false;
+  }
+
+  const hasAnySigningOrder = nonCcRecipients.some((recipient) => typeof recipient.signingOrder === 'number');
+
+  if (!hasAnySigningOrder) {
+    return nonCcRecipients[nonCcRecipients.length - 1]?.role === RecipientRole.ASSISTANT;
+  }
+
+  const maxOrder = Math.max(...nonCcRecipients.map((recipient) => recipient.signingOrder ?? Number.MAX_SAFE_INTEGER));
+
+  return nonCcRecipients.some(
+    (recipient) =>
+      (recipient.signingOrder ?? Number.MAX_SAFE_INTEGER) === maxOrder && recipient.role === RecipientRole.ASSISTANT,
+  );
 };
 
 export const sortRecipientsForSigningOrder = <T extends RecipientWithSigningOrder>(recipients: T[]): T[] => {