fixup

lib/internal/timers.js

@@ -173,7 +173,11 @@ class Timeout {
   // Timer constructor function.
   // The entire prototype is defined in lib/timers.js
   constructor(callback, after, args, isRepeat, isRefed) {
-    after === undefined ? 1 : after *= 1; // Coalesce to number or NaN
+    if (after === undefined) {
+      after = 1;
+    } else {
+      after *= 1; // Coalesce to number or NaN
+    }
 
     if (!(after >= 1 && after <= TIMEOUT_MAX)) {
       if (after > TIMEOUT_MAX) {

test/parallel/test-timers-not-emit-duration-zero.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+
+function timerNotCanceled() {
+  assert.fail('Timer should be canceled');
+}
+
+process.on(
+  'warning',
+  common.mustNotCall(() => {
+    assert.fail('Timer should be canceled');
+  })
+);
+
+{
+  const timeout = setTimeout(timerNotCanceled, 0);
+  clearTimeout(timeout);
+}
+
+{
+  const interval = setInterval(timerNotCanceled, 0);
+  clearInterval(interval);
+}
+
+{
+  const timeout = setTimeout(timerNotCanceled, 0);
+  timeout.refresh();
+  clearTimeout(timeout);
+}