From 9f36ce85bed4d7a33a947725584e23fad776951e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julien=20Valverd=C3=A9?= <julien.valverde@mailo.com>
Date: Mon, 19 Feb 2024 19:22:07 +0100
Subject: [PATCH] Extend work

---
 src/util/extend.ts | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/util/extend.ts b/src/util/extend.ts
index d2a3824..e4a1460 100644
--- a/src/util/extend.ts
+++ b/src/util/extend.ts
@@ -21,7 +21,11 @@ import { CommonKeys } from "."
 
 
 export type Extend<T extends readonly object[]> = (
-    T extends [infer Super, infer Self, ...infer Rest extends object[]]
+    T extends [
+        infer Super,
+        infer Self,
+        ...infer Rest extends object[]
+    ]
         ? Pick<Self, CommonKeys<Self, Super>> extends Pick<Super, CommonKeys<Self, Super>>
             ? Extend<[
                 Omit<Super, CommonKeys<Self, Super>> & Self,
@@ -34,12 +38,22 @@ export type Extend<T extends readonly object[]> = (
 )
 
 export type Extendable<T extends readonly object[]> = (
-    T extends [infer Super, infer Self, ...infer Rest extends object[]]
+    T extends [
+        infer Super   extends object,
+        infer Self    extends object,
+        ...infer Rest extends object[],
+    ]
         ? Pick<Self, CommonKeys<Self, Super>> extends Pick<Super, CommonKeys<Self, Super>>
             ? Extendable<[
-                Omit<Super, CommonKeys<Self, Super>> & Self,
+                Super & Self,
                 ...Rest,
             ]>
             : false
         : true
 )
+
+export type NonExtendableKeys<T extends readonly object[]> = (
+    Extendable<T> extends false
+        ? {}
+        : never
+)