From 6677a406d39eeb766c365710266d25cb80e77248 Mon Sep 17 00:00:00 2001
From: Wesley Wigham <wwigham@gmail.com>
Date: Mon, 26 Apr 2021 21:45:12 -0700
Subject: [PATCH] Add assertion on invalid cache set

---
 src/compiler/checker.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index f4ee7960f1074..6655b32fad392 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -30395,6 +30395,9 @@ namespace ts {
                     assignBindingElementTypes(declaration.name);
                 }
             }
+            else if (type) {
+                Debug.assertEqual(links.type, type, "Parameter symbol already has a cached type which differs from newly assigned type");
+            }
         }
 
         // When contextual typing assigns a type to a parameter that contains a binding pattern, we also need to push