From a2c2a6644fdbd4f6d663f3dfaaa6678de70a95e1 Mon Sep 17 00:00:00 2001
From: Dor Meiri <37194716+dormeiri@users.noreply.github.com>
Date: Tue, 5 Dec 2023 15:51:00 +0200
Subject: [PATCH] Call `setTimeout` only when execution is delayed (#46)

---
 index.js | 10 +++++++---
 test.js  |  9 ++++++++-
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/index.js b/index.js
index b3bbc6b..8336ae6 100644
--- a/index.js
+++ b/index.js
@@ -80,9 +80,13 @@ export default function pThrottle({limit, interval, strict}) {
 					queue.delete(timeoutId);
 				};
 
-				timeoutId = setTimeout(execute, getDelay());
-
-				queue.set(timeoutId, reject);
+				const delay = getDelay();
+				if (delay > 0) {
+					timeoutId = setTimeout(execute, delay);
+					queue.set(timeoutId, reject);
+				} else {
+					execute();
+				}
 			});
 		};
 
diff --git a/test.js b/test.js
index f5b53cf..9a240c8 100644
--- a/test.js
+++ b/test.js
@@ -25,6 +25,7 @@ test('main', async t => {
 test('queue size', async t => {
 	const limit = 10;
 	const interval = 100;
+	const delayedExecutions = 20;
 	const throttled = pThrottle({limit, interval})(() => Date.now());
 	const promises = [];
 
@@ -34,7 +35,13 @@ test('queue size', async t => {
 		promises.push(throttled());
 	}
 
-	t.is(throttled.queueSize, limit);
+	t.is(throttled.queueSize, 0);
+
+	for (let index = 0; index < delayedExecutions; index++) {
+		promises.push(throttled());
+	}
+
+	t.is(throttled.queueSize, delayedExecutions);
 
 	await Promise.all(promises);