From 61ce8148e3272a21a4cb009537c2db761b21a9df Mon Sep 17 00:00:00 2001
From: Justin Fagnani <justinfagnani@google.com>
Date: Thu, 2 Feb 2023 09:21:50 -0800
Subject: [PATCH] Add type parameter for key to createContext() (#3628)

---
 .changeset/happy-apricots-pay.md                | 5 +++++
 packages/labs/context/src/lib/create-context.ts | 6 +++---
 2 files changed, 8 insertions(+), 3 deletions(-)
 create mode 100644 .changeset/happy-apricots-pay.md

diff --git a/.changeset/happy-apricots-pay.md b/.changeset/happy-apricots-pay.md
new file mode 100644
index 0000000000..21799b9131
--- /dev/null
+++ b/.changeset/happy-apricots-pay.md
@@ -0,0 +1,5 @@
+---
+'@lit-labs/context': patch
+---
+
+Add type parameter for key to createContext()
diff --git a/packages/labs/context/src/lib/create-context.ts b/packages/labs/context/src/lib/create-context.ts
index 5e8840ba49..2e4ad4220f 100644
--- a/packages/labs/context/src/lib/create-context.ts
+++ b/packages/labs/context/src/lib/create-context.ts
@@ -49,8 +49,8 @@ export type ContextType<Key extends Context<unknown, unknown>> =
  *
  * @param key a context key value
  * @template ValueType the type of value that can be provided by this context.
- * @returns the context key value with the correct type
+ * @returns the context key value cast to `Context<K, ValueType>`
  */
-export function createContext<ValueType>(key: unknown) {
-  return key as Context<typeof key, ValueType>;
+export function createContext<ValueType, K = unknown>(key: K) {
+  return key as Context<K, ValueType>;
 }