From c6b72831e30c2ce3c540488ebea65cbe4a546b10 Mon Sep 17 00:00:00 2001
From: echo094 <20028238+echo094@users.noreply.github.com>
Date: Mon, 16 Oct 2023 18:55:27 +0800
Subject: [PATCH] visitor/calculate-binary: check if left and right are both
 constants before replacing

Signed-off-by: echo094 <20028238+echo094@users.noreply.github.com>
---
 src/visitor/calculate-binary.js | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/visitor/calculate-binary.js b/src/visitor/calculate-binary.js
index e871f6a..3b87d18 100644
--- a/src/visitor/calculate-binary.js
+++ b/src/visitor/calculate-binary.js
@@ -1,7 +1,18 @@
 const generator = require('@babel/generator').default
+const t = require('@babel/types')
 
+/**
+ * Calculate BinaryExpression if left and right are both literals.
+ * Otherwise, the expression can't be simplified.
+ *
+ * For example, `typeof window` can be calculated but it's not constant.
+ */
 module.exports = {
   BinaryExpression(path) {
+    const { left, right } = path.node
+    if (!t.isLiteral(left) || !t.isLiteral(right)) {
+      return
+    }
     const code = generator(path.node).code
     try {
       const ret = eval(code)