From 5e980f68736166d2d1d2cf6b3552b7ef1f10ccfc Mon Sep 17 00:00:00 2001
From: Thomas Scholtes <thomas-scholtes@gmx.de>
Date: Fri, 13 Nov 2020 18:39:55 +0100
Subject: [PATCH] fix(typescript): fix library type declrations

We fix the type declaration file for the `typescript` plugin.

Signed-off-by: Thomas Scholtes <thomas-scholtes@gmx.de>
---
 packages/typescript/types/index.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/typescript/types/index.d.ts b/packages/typescript/types/index.d.ts
index c9b485e05..c43991017 100644
--- a/packages/typescript/types/index.d.ts
+++ b/packages/typescript/types/index.d.ts
@@ -38,7 +38,7 @@ export interface RollupTypescriptPluginOptions {
   transformers?: CustomTransformerFactories;
 }
 
-type ElementType<T extends Array<any>> = T extends (infer U)[] ? U : never;
+type ElementType<T extends Array<any> | undefined> = T extends (infer U)[] ? U : never;
 
 export type TransformerStage = keyof CustomTransformers;
 type StagedTransformerFactory<T extends TransformerStage> = ElementType<CustomTransformers[T]>;