grpc-js: Add type predicate to fix errors for isFunction

grpc · Apr 27, 2021 · 923b44b · 923b44b
1 parent 7a8cd5a
commit 923b44b
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/packages/grpc-js/src/client.ts b/packages/grpc-js/src/client.ts
@@ -55,7 +55,7 @@ const INTERCEPTOR_SYMBOL = Symbol();
 const INTERCEPTOR_PROVIDER_SYMBOL = Symbol();
 const CALL_INVOCATION_TRANSFORMER_SYMBOL = Symbol();
 
-function isFunction<ResponseType>(arg: Metadata | CallOptions | UnaryCallback<ResponseType>): boolean {
+function isFunction<ResponseType>(arg: Metadata | CallOptions | UnaryCallback<ResponseType> | undefined): arg is UnaryCallback<ResponseType>{
   return Object.prototype.toString.call(arg) === '[object Function]'
 }