feat: avoid registering duplicated handlers

simonecorsi · Jul 7, 2021 · 30422b8 · 30422b8
1 parent 54a26ce
commit 30422b8
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/index.js b/index.js
@@ -40,6 +40,9 @@ module.exports = function fine(
   validateParameters(timeout, events, callbacks);
 
   for (const event of events) {
+    if (process.listenerCount(event) > 0) {
+      throw new Error(`A ${event} handler is already registered`);
+    }
     process.once(event, () => {
       const code = event.match("^SIG") ? 0 : 1;
       process.stdout.write(`[${event}] exiting with code ${code}\n`);