From d158a48945a08591ab6b9e746540e3fca78f6509 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=B2=20Ribaudo?= <nicolo.ribaudo@gmail.com>
Date: Thu, 6 Jan 2022 18:37:45 +0100
Subject: [PATCH] Don't mutate `@babel/register` options (#14107)

---
 packages/babel-register/src/node.js   |  5 ++-
 packages/babel-register/test/index.js | 54 ++++++++++++++++++++++++++-
 2 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/packages/babel-register/src/node.js b/packages/babel-register/src/node.js
index 8457f228f732..5ab5a712d95e 100644
--- a/packages/babel-register/src/node.js
+++ b/packages/babel-register/src/node.js
@@ -5,7 +5,10 @@
 const hook = require("./hook");
 const { LocalClient } = require("./worker-client");
 
-const register = hook.register.bind(null, new LocalClient());
+const client = new LocalClient();
+function register(opts = {}) {
+  return hook.register(client, { ...opts });
+}
 
 module.exports = Object.assign(register, {
   revert: hook.revert,
diff --git a/packages/babel-register/test/index.js b/packages/babel-register/test/index.js
index ba4b0250a1c2..99ea1749ed9f 100644
--- a/packages/babel-register/test/index.js
+++ b/packages/babel-register/test/index.js
@@ -118,7 +118,33 @@ describe("@babel/register", function () {
         });
       }
 
-      buildTests(require.resolve(".."));
+      const { setupRegister } = buildTests(require.resolve(".."));
+
+      it("does not mutate options", () => {
+        const proxyHandler = {
+          defineProperty: jest.fn(Reflect.defineProperty),
+          deleteProperty: jest.fn(Reflect.deleteProperty),
+          set: jest.fn(Reflect.set),
+        };
+
+        setupRegister(
+          new Proxy(
+            {
+              babelrc: true,
+              sourceMaps: false,
+              cwd: path.dirname(testFileMjs),
+              extensions: [".js"],
+            },
+            proxyHandler,
+          ),
+        );
+
+        currentHook(testFileContent, testFile);
+
+        expect(proxyHandler.defineProperty).not.toHaveBeenCalled();
+        expect(proxyHandler.deleteProperty).not.toHaveBeenCalled();
+        expect(proxyHandler.set).not.toHaveBeenCalled();
+      });
     });
   }
 
@@ -344,6 +370,32 @@ describe("@babel/register", function () {
       expect(convertSourceMap).toMatch("/* transformed */");
     });
 
+    test("does not mutate options", () => {
+      const proxyHandler = {
+        defineProperty: jest.fn(Reflect.defineProperty),
+        deleteProperty: jest.fn(Reflect.deleteProperty),
+        set: jest.fn(Reflect.set),
+      };
+
+      setupRegister(
+        new Proxy(
+          {
+            babelrc: true,
+            sourceMaps: false,
+            cwd: path.dirname(testFileMjs),
+            extensions: [".js"],
+          },
+          proxyHandler,
+        ),
+      );
+
+      currentHook(testFileContent, testFile);
+
+      expect(proxyHandler.defineProperty).not.toHaveBeenCalled();
+      expect(proxyHandler.deleteProperty).not.toHaveBeenCalled();
+      expect(proxyHandler.set).not.toHaveBeenCalled();
+    });
+
     return { setupRegister, revertRegister };
   }
 });