From 945babbaacb0cbb09c39f554c4141bed9647a9c0 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Sun, 15 Sep 2019 09:49:57 -0700
Subject: [PATCH] Fix inference circularity error triggered by exhaustive
 switch analysis

---
 src/compiler/transformers/generators.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/transformers/generators.ts b/src/compiler/transformers/generators.ts
index 3b1a8379e07..cc16aef6009 100644
--- a/src/compiler/transformers/generators.ts
+++ b/src/compiler/transformers/generators.ts
@@ -2871,7 +2871,7 @@ namespace ts {
         function tryEnterOrLeaveBlock(operationIndex: number): void {
             if (blocks) {
                 for (; blockIndex < blockActions!.length && blockOffsets![blockIndex] <= operationIndex; blockIndex++) {
-                    const block = blocks[blockIndex];
+                    const block: CodeBlock = blocks[blockIndex];
                     const blockAction = blockActions![blockIndex];
                     switch (block.kind) {
                         case CodeBlockKind.Exception: