From 06c3c4eb72323fe79138574c4eaa2770da4f4310 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=B2=20Ribaudo?= <nicolo.ribaudo@gmail.com>
Date: Mon, 31 Oct 2022 19:40:55 +0100
Subject: [PATCH] Do not mark `in` and `instanceof` as constant

---
 .../test/fixtures/regression/15098/exec.js               | 7 +++++++
 .../test/fixtures/regression/15098/input.js              | 4 ++++
 .../test/fixtures/regression/15098/options.json          | 3 +++
 .../test/fixtures/regression/15098/output.js             | 9 +++++++++
 packages/babel-traverse/src/path/introspection.ts        | 3 +++
 5 files changed, 26 insertions(+)
 create mode 100644 packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/exec.js
 create mode 100644 packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/input.js
 create mode 100644 packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/options.json
 create mode 100644 packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/output.js

diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/exec.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/exec.js
new file mode 100644
index 000000000000..1c84161a55af
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/exec.js
@@ -0,0 +1,7 @@
+expect(() => {
+  class X { [0 in 0]; }
+}).toThrow();
+
+expect(() => {
+  class X { [0 instanceof 0]; }
+}).toThrow();
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/input.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/input.js
new file mode 100644
index 000000000000..33d98a95318d
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/input.js
@@ -0,0 +1,4 @@
+class X {
+  [ 0 in 0 ];
+  [ 0 instanceof 0 ];
+}
\ No newline at end of file
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/options.json b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/options.json
new file mode 100644
index 000000000000..19ed5174f545
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["proposal-class-properties"]
+}
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/output.js
new file mode 100644
index 000000000000..e6a60648b3fe
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/output.js
@@ -0,0 +1,9 @@
+let _ref, _ref2;
+_ref = 0 in 0;
+_ref2 = 0 instanceof 0;
+class X {
+  constructor() {
+    babelHelpers.defineProperty(this, _ref, void 0);
+    babelHelpers.defineProperty(this, _ref2, void 0);
+  }
+}
diff --git a/packages/babel-traverse/src/path/introspection.ts b/packages/babel-traverse/src/path/introspection.ts
index f4c8e2db9153..97b65d935741 100644
--- a/packages/babel-traverse/src/path/introspection.ts
+++ b/packages/babel-traverse/src/path/introspection.ts
@@ -634,7 +634,10 @@ export function isConstantExpression(this: NodePath): boolean {
   }
 
   if (this.isBinaryExpression()) {
+    const { operator } = this.node;
     return (
+      operator !== "in" &&
+      operator !== "instanceof" &&
       this.get("left").isConstantExpression() &&
       this.get("right").isConstantExpression()
     );