From e5b727987f79973ab83c210b8fb30a4c61659782 Mon Sep 17 00:00:00 2001
From: Andrej Dyck <43913051+andrej-dyck@users.noreply.github.com>
Date: Tue, 23 Jul 2024 10:33:49 +0200
Subject: [PATCH] add optional utility type

---
 types/Optional.ts | 18 ++++++++++++++++++
 types/index.ts    |  1 +
 2 files changed, 19 insertions(+)
 create mode 100644 types/Optional.ts

diff --git a/types/Optional.ts b/types/Optional.ts
new file mode 100644
index 0000000..2929cc0
--- /dev/null
+++ b/types/Optional.ts
@@ -0,0 +1,18 @@
+/**
+ * Makes some properties of a record optional.
+ */
+export type Optional<T, K extends keyof Record<PropertyKey, unknown>> = Omit<T, K> & { [K in keyof T]?: T[K] }
+
+/*
+ * Example:
+ *   type CartItem = {
+ *     id: string,
+ *     sku: string,
+ *     quantity: number,
+ *   }
+ *
+ *   function addItem(item: Optional<CartItem, 'id' | 'quantity'>) {
+ *     // typeof item: { id?: string, sku: string, quantity?: number }
+ *     ...
+ *   }
+ */
diff --git a/types/index.ts b/types/index.ts
index efe43e2..02cd181 100644
--- a/types/index.ts
+++ b/types/index.ts
@@ -1,2 +1,3 @@
 export * from './Branded.ts'
 export * from './DeepPartial.ts'
+export * from './Optional.ts'