From 57a26e0277d2aab6a88193a44ffee78e360b57b1 Mon Sep 17 00:00:00 2001
From: Timur Shemsedinov <timur.shemsedinov@gmail.com>
Date: Mon, 22 Feb 2021 11:31:40 +0200
Subject: [PATCH] Implemented `await delay(msec, signal)`

PR-URL: https://github.com/metarhia/metautil/pull/31
---
 CHANGELOG.md                  |  1 +
 lib/utilities.js              | 11 +++++++++++
 test/{timeout.js => async.js} | 22 +++++++++++++++++++++-
 3 files changed, 33 insertions(+), 1 deletion(-)
 rename test/{timeout.js => async.js} (50%)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6b42850..7416721 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## [Unreleased][unreleased]
 
+- Implemented `await delay(msec, signal)`
 - Fix timeout behaviour to reject promise (throw)
 - Generate errors on timeout and on abort timeout
 
diff --git a/lib/utilities.js b/lib/utilities.js
index cf54376..f53ef6f 100644
--- a/lib/utilities.js
+++ b/lib/utilities.js
@@ -162,6 +162,16 @@ const timeout = (msec, signal = null) =>
     });
   });
 
+const delay = (msec, signal = null) =>
+  new Promise((resolve, reject) => {
+    const timer = setTimeout(resolve, msec);
+    if (!signal) return;
+    signal.on('abort', () => {
+      clearTimeout(timer);
+      reject(new Error('Delay aborted'));
+    });
+  });
+
 module.exports = {
   random,
   sample,
@@ -179,4 +189,5 @@ module.exports = {
   parseCookies,
   createAbortController,
   timeout,
+  delay,
 };
diff --git a/test/timeout.js b/test/async.js
similarity index 50%
rename from test/timeout.js
rename to test/async.js
index 8ded1da..97047fd 100644
--- a/test/timeout.js
+++ b/test/async.js
@@ -1,7 +1,7 @@
 'use strict';
 
 const metatests = require('metatests');
-const { timeout, createAbortController } = require('..');
+const { timeout, delay, createAbortController } = require('..');
 
 metatests.test('Abortable timeout', async (test) => {
   try {
@@ -22,3 +22,23 @@ metatests.test('Abortable timeout', async (test) => {
     test.end();
   }
 });
+
+metatests.test('Abortable delay', async (test) => {
+  try {
+    const res = await delay(10);
+    test.strictSame(res, undefined);
+  } catch (err) {
+    test.error(new Error('Should not be executed'));
+  }
+  const ac = createAbortController();
+  setTimeout(() => {
+    ac.abort();
+  }, 10);
+  try {
+    await delay(100, ac.signal);
+    test.error(new Error('Should not be executed'));
+  } catch (err) {
+    test.strictSame(err.message, 'Delay aborted');
+    test.end();
+  }
+});