From 8b5edaa1897e5844acbb16686aed54355fdbcdd1 Mon Sep 17 00:00:00 2001
From: Philippe Serhal <philippe@goodeggs.com>
Date: Thu, 7 Oct 2021 18:55:30 -0400
Subject: [PATCH] docs(readme): add note about TypeScript

---
 README.md | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/README.md b/README.md
index 9d602e93..5e53aa15 100644
--- a/README.md
+++ b/README.md
@@ -50,6 +50,22 @@ jsonFetch('http://www.test.com/products/1234', {
   });
 ```
 
+### TypeScript
+
+This library comes with built-in TypeScript type declarations.
+
+Due to complexities in dealing with isomorphic-fetch - which uses whatwg-fetch in browsers and node-fetch
+in node.js, which are subtly different - these type declarations only work if you include the `DOM` built-in
+TypeScript lib in your `tsconfig.json`. For example:
+```json
+{
+  "lib": ["DOM", "ES2020"]
+}
+```
+This happens implicitly if you don't set a `lib`.
+
+This may be fixed in the future.
+
 ### Retry Behavior
 
 By default, jsonFetch doesn't retry requests. However, you may opt in to jsonFetch's very flexible retry behavior, provided by the excellent [`promise-retry`](https://github.com/IndigoUnited/node-promise-retry) library. Here's a quick example: