From a7acde3885df4583ed84e780c4b0fce5815631f6 Mon Sep 17 00:00:00 2001
From: Sneh Khatri <khatris2014@gmail.com>
Date: Tue, 14 Dec 2021 02:21:57 +0530
Subject: [PATCH] Fix: default rest argument array elements as undefined
 (#14032)

---
 packages/babel-plugin-transform-parameters/src/rest.ts   | 2 ++
 .../test/fixtures/parameters/default-arguments/exec.js   | 4 ++++
 .../test/fixtures/parameters/default-arguments/input.js  | 4 ++++
 .../test/fixtures/parameters/default-arguments/output.js | 9 +++++++++
 .../rest-argument-with-other-arguments/exec.js           | 5 +++++
 .../rest-argument-with-other-arguments/input.js          | 5 +++++
 .../rest-argument-with-other-arguments/output.js         | 9 +++++++++
 7 files changed, 38 insertions(+)
 create mode 100644 packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/exec.js
 create mode 100644 packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/input.js
 create mode 100644 packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/output.js
 create mode 100644 packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/exec.js
 create mode 100644 packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/input.js
 create mode 100644 packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/output.js

diff --git a/packages/babel-plugin-transform-parameters/src/rest.ts b/packages/babel-plugin-transform-parameters/src/rest.ts
index 196c11f82dfa..3d784f58b024 100644
--- a/packages/babel-plugin-transform-parameters/src/rest.ts
+++ b/packages/babel-plugin-transform-parameters/src/rest.ts
@@ -242,6 +242,8 @@ export default function convertFunctionRest(path) {
 
   let rest = node.params.pop().argument;
 
+  if (rest.name === "arguments") scope.rename(rest.name);
+
   const argsId = t.identifier("arguments");
 
   if (t.isPattern(rest)) {
diff --git a/packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/exec.js b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/exec.js
new file mode 100644
index 000000000000..808a93a1a76f
--- /dev/null
+++ b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/exec.js
@@ -0,0 +1,4 @@
+function func(...arguments) {
+    return arguments;
+}
+expect(func(1, 2, 3)).toStrictEqual([1, 2, 3])
diff --git a/packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/input.js b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/input.js
new file mode 100644
index 000000000000..e14a98de58b8
--- /dev/null
+++ b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/input.js
@@ -0,0 +1,4 @@
+function func(...arguments) {
+    console.log(arguments); // [1, 2, 3]
+}
+func(1, 2, 3);
diff --git a/packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/output.js b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/output.js
new file mode 100644
index 000000000000..a477e9689c75
--- /dev/null
+++ b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/default-arguments/output.js
@@ -0,0 +1,9 @@
+function func() {
+  for (var _len = arguments.length, _arguments = new Array(_len), _key = 0; _key < _len; _key++) {
+    _arguments[_key] = arguments[_key];
+  }
+
+  console.log(_arguments); // [1, 2, 3]
+}
+
+func(1, 2, 3);
diff --git a/packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/exec.js b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/exec.js
new file mode 100644
index 000000000000..5d73453be999
--- /dev/null
+++ b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/exec.js
@@ -0,0 +1,5 @@
+function func(a, b, ...arguments) {
+    return [a, b, arguments];
+}
+
+expect(func('a', 'b', 1, 2, 3)).toStrictEqual(['a', 'b', [1, 2, 3]])
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/input.js b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/input.js
new file mode 100644
index 000000000000..29d87e8cabcc
--- /dev/null
+++ b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/input.js
@@ -0,0 +1,5 @@
+function func(a, b, ...arguments) {
+    return [a, b, arguments];
+}
+
+func('a', 'b', 1, 2, 3)
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/output.js b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/output.js
new file mode 100644
index 000000000000..84ba9facd4b6
--- /dev/null
+++ b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/rest-argument-with-other-arguments/output.js
@@ -0,0 +1,9 @@
+function func(a, b) {
+  for (var _len = arguments.length, _arguments = new Array(_len > 2 ? _len - 2 : 0), _key = 2; _key < _len; _key++) {
+    _arguments[_key - 2] = arguments[_key];
+  }
+
+  return [a, b, _arguments];
+}
+
+func('a', 'b', 1, 2, 3);