feat(types): improve setActivePinia types

diff --git a/packages/pinia/src/rootStore.ts b/packages/pinia/src/rootStore.ts
index 0509a5c8eb4e5f4f1f49f7292c69f4b4e2463855..cc212401a826dc81e4cd05a2d082f6963204db8e 100644 (file)
--- a/packages/pinia/src/rootStore.ts
+++ b/packages/pinia/src/rootStore.ts
@@ -30,8 +30,14 @@ export let activePinia: Pinia | undefined
  *
  * @param pinia - Pinia instance
  */
-export const setActivePinia = (pinia: Pinia | undefined) =>
-  (activePinia = pinia)
+// @ts-expect-error: cannot constrain the type of the return
+export const setActivePinia: _SetActivePinia = (pinia) => (activePinia = pinia)
+
+interface _SetActivePinia {
+  (pinia: Pinia): Pinia
+  (pinia: undefined): undefined
+  (pinia: Pinia | undefined): Pinia | undefined
+}
 
 /**
  * Get the currently active pinia if there is any.