From 767c7b43a46a3921eb08e2c327722b305190d9c3 Mon Sep 17 00:00:00 2001
From: magic-akari <akari.ccino@gmail.com>
Date: Mon, 27 Jun 2022 14:39:21 +0800
Subject: [PATCH] fix: preserve function params type if possible (#14694)

* fix: preserve function params type if possible

* chore: add test for default value
---
 .../src/params.ts                              |  1 +
 .../parameters/preserve-types/input.ts         | 13 +++++++++++++
 .../parameters/preserve-types/output.js        | 18 ++++++++++++++++++
 3 files changed, 32 insertions(+)
 create mode 100644 packages/babel-plugin-transform-parameters/test/fixtures/parameters/preserve-types/input.ts
 create mode 100644 packages/babel-plugin-transform-parameters/test/fixtures/parameters/preserve-types/output.js

diff --git a/packages/babel-plugin-transform-parameters/src/params.ts b/packages/babel-plugin-transform-parameters/src/params.ts
index 9b21a95952ad..2ed848779811 100644
--- a/packages/babel-plugin-transform-parameters/src/params.ts
+++ b/packages/babel-plugin-transform-parameters/src/params.ts
@@ -187,6 +187,7 @@ export default function convertFunctionParams(
       body.push(defNode);
     } else if (param.isObjectPattern() || param.isArrayPattern()) {
       const uid = path.scope.generateUidIdentifier("ref");
+      uid.typeAnnotation = param.node.typeAnnotation;
 
       const defNode = t.variableDeclaration("let", [
         t.variableDeclarator(param.node, uid),
diff --git a/packages/babel-plugin-transform-parameters/test/fixtures/parameters/preserve-types/input.ts b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/preserve-types/input.ts
new file mode 100644
index 000000000000..b9da79cb2a66
--- /dev/null
+++ b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/preserve-types/input.ts
@@ -0,0 +1,13 @@
+type Point = {
+  x: number;
+  y: number;
+};
+
+function value({ x, y }: Point) {
+  return x * y;
+}
+
+function valueWithDefault({ x, y }: Point = {}) {
+  return x * y;
+}
+
diff --git a/packages/babel-plugin-transform-parameters/test/fixtures/parameters/preserve-types/output.js b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/preserve-types/output.js
new file mode 100644
index 000000000000..f8dcb46486ee
--- /dev/null
+++ b/packages/babel-plugin-transform-parameters/test/fixtures/parameters/preserve-types/output.js
@@ -0,0 +1,18 @@
+type Point = {
+  x: number;
+  y: number;
+};
+
+function value(_ref: Point) {
+  var x = _ref.x,
+      y = _ref.y;
+  return x * y;
+}
+
+function valueWithDefault() {
+  var _ref2 = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {},
+      x = _ref2.x,
+      y = _ref2.y;
+
+  return x * y;
+}