From 3c9cf99897b050d55d8a7e8d4f67c0aee149a5f7 Mon Sep 17 00:00:00 2001
From: Nicholas Jamieson <nicholas@cartant.com>
Date: Sun, 6 Oct 2019 07:23:20 +1000
Subject: [PATCH] chore: make subscribeToResult signatures safer

---
 src/internal/util/subscribeToResult.ts | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/internal/util/subscribeToResult.ts b/src/internal/util/subscribeToResult.ts
index 270660e0ec..31368ce6c2 100644
--- a/src/internal/util/subscribeToResult.ts
+++ b/src/internal/util/subscribeToResult.ts
@@ -5,18 +5,33 @@ import { Subscriber } from '../Subscriber';
 import { subscribeTo } from './subscribeTo';
 import { Observable } from '../Observable';
 
+export function subscribeToResult<T, R>(
+  outerSubscriber: OuterSubscriber<T, R>,
+  result: any,
+  outerValue: undefined,
+  outerIndex: undefined,
+  innerSubscriber: InnerSubscriber<T, R>
+): Subscription | undefined;
+
+export function subscribeToResult<T, R>(
+  outerSubscriber: OuterSubscriber<T, R>,
+  result: any,
+  outerValue?: T,
+  outerIndex?: number
+): Subscription | undefined;
+
 export function subscribeToResult<T, R>(
   outerSubscriber: OuterSubscriber<T, R>,
   result: any,
   outerValue?: T,
   outerIndex?: number,
-  destination: Subscriber<R> = new InnerSubscriber(outerSubscriber, outerValue, outerIndex)
+  innerSubscriber: Subscriber<R> = new InnerSubscriber(outerSubscriber, outerValue, outerIndex)
 ): Subscription | undefined {
-  if (destination.closed) {
+  if (innerSubscriber.closed) {
     return undefined;
   }
   if (result instanceof Observable) {
-    return result.subscribe(destination);
+    return result.subscribe(innerSubscriber);
   }
-  return subscribeTo(result)(destination) as Subscription;
+  return subscribeTo(result)(innerSubscriber) as Subscription;
 }