From 7a397c996f4110356f50ebfdf823c4248123e503 Mon Sep 17 00:00:00 2001
From: Martin Eneqvist <marlun78@hotmail.com>
Date: Mon, 22 Apr 2024 13:19:06 +0200
Subject: [PATCH] Adds custom assertion message example to README

---
 readme.md | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/readme.md b/readme.md
index 527745a..7bbaacf 100644
--- a/readme.md
+++ b/readme.md
@@ -45,6 +45,15 @@ assert.string(2);
 //=> Error: Expected value which is `string`, received value of type `number`.
 ```
 
+Most assertions also support an optional custom error message.
+
+```js
+import {assert} from '@sindresorhus/is';
+
+assert.nonEmptyString(process.env.API_URL, 'API_URL env variable is required.');
+//=> Error: API_URL env variable is required.
+```
+
 And with TypeScript:
 
 ```ts