From 760d9837dcd555e2b7571b683780e86f1d4160d9 Mon Sep 17 00:00:00 2001
From: Boopathi Rajaa <me@boopathi.in>
Date: Thu, 10 Aug 2017 11:37:29 +0200
Subject: [PATCH] Add deopt paths for let/const bindings in evaluate helper

---
 packages/babel-helper-evaluate-path/src/index.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/packages/babel-helper-evaluate-path/src/index.js b/packages/babel-helper-evaluate-path/src/index.js
index 4247d3f4d..debf58588 100644
--- a/packages/babel-helper-evaluate-path/src/index.js
+++ b/packages/babel-helper-evaluate-path/src/index.js
@@ -141,6 +141,16 @@ function evaluateBasedOnControlFlow(binding, refPath) {
   } else if (binding.kind === "let" || binding.kind === "const") {
     // binding.path is the declarator
     const declarator = binding.path;
+    const declaration = declarator.parentPath;
+
+    if (
+      declaration.parentPath.isIfStatement() ||
+      declaration.parentPath.isLoop() ||
+      declaration.parentPath.isSwitchCase()
+    ) {
+      return { shouldDeopt: true };
+    }
+
     let scopePath = declarator.scope.path;
     if (scopePath.isFunction()) {
       scopePath = scopePath.get("body");