test: re-implement promises.setInterval() test robustly

By using events, we can make sure the call to `controller.abort()`
doesn't happen before the next iteration starts.

Fixes: #37226

test/parallel/test-timers-promisified.js

@@ -10,6 +10,7 @@ const child_process = require('child_process');
 const { NodeEventTarget } = require('internal/event_target');
 
 const timerPromises = require('timers/promises');
+const EventEmitter = require('events');
 
 /* eslint-disable no-restricted-syntax */
 
@@ -348,6 +349,33 @@ process.on('multipleResolves', common.mustNotCall());
       assert.strictEqual(loopCount, 5);
     }));
   }
+
+  {
+    // Check that if we abort when we have some unresolved callbacks,
+    // we actually call them.
+    const controller = new AbortController();
+    const myEvent = new EventEmitter();
+    const { signal } = controller;
+    const delay = 10;
+    let totalIterations = 0;
+    const timeoutLoop = runInterval(async (iterationNumber) => {
+      myEvent.emit('myevent');
+      // The call to abort() will typically happen while we're awaiting here.
+      await setTimeout(delay);
+      if (iterationNumber === 2) {
+        myEvent.once('myevent', () => {
+          controller.abort();
+        });
+      }
+      if (iterationNumber > totalIterations) {
+        totalIterations = iterationNumber;
+      }
+    }, delay, signal);
+
+    timeoutLoop.catch(common.mustCall(() => {
+      assert.ok(totalIterations >= 3, `iterations was ${totalIterations} < 3`);
+    }));
+  }
 }
 
 {