Do not mark in and instanceof as constant expressions (#15106)

Do not mark `in` and `instanceof` as constant

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();

packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/input.js

@@ -0,0 +1,4 @@
+class X {
+  [ 0 in 0 ];
+  [ 0 instanceof 0 ];
+}

packages/babel-plugin-proposal-class-properties/test/fixtures/regression/15098/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["proposal-class-properties"]
+}

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);
+  }
+}

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()
     );