From 335622f75db4c30159d33a62a205630da6c056ee Mon Sep 17 00:00:00 2001
From: Arthur <chentao19940815@gmail.com>
Date: Mon, 10 Jan 2022 22:39:52 +0800
Subject: [PATCH] Delete useless check for variable redeclaration (#14129)

---
 packages/babel-traverse/src/scope/binding.ts | 2 +-
 packages/babel-traverse/src/scope/index.ts   | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/packages/babel-traverse/src/scope/binding.ts b/packages/babel-traverse/src/scope/binding.ts
index ea521ffac8..48f15692f8 100644
--- a/packages/babel-traverse/src/scope/binding.ts
+++ b/packages/babel-traverse/src/scope/binding.ts
@@ -2,7 +2,7 @@ import type NodePath from "../path";
 import type * as t from "@babel/types";
 import type Scope from "./index";
 
-type BindingKind =
+export type BindingKind =
   | "var" /* var declarator */
   | "let" /* let declarator, class declaration id, catch clause parameters */
   | "const" /* const declarator */
diff --git a/packages/babel-traverse/src/scope/index.ts b/packages/babel-traverse/src/scope/index.ts
index 71e43ebb00..068b67b5b2 100644
--- a/packages/babel-traverse/src/scope/index.ts
+++ b/packages/babel-traverse/src/scope/index.ts
@@ -3,6 +3,7 @@ import type NodePath from "../path";
 import traverse from "../index";
 import type { TraverseOptions } from "../index";
 import Binding from "./binding";
+import type { BindingKind } from "./binding";
 import globals from "globals";
 import {
   NOT_LOCAL_BINDING,
@@ -569,7 +570,7 @@ export default class Scope {
 
   checkBlockScopedCollisions(
     local: Binding,
-    kind: string,
+    kind: BindingKind,
     name: string,
     id: any,
   ) {
@@ -587,7 +588,7 @@ export default class Scope {
       local.kind === "const" ||
       local.kind === "module" ||
       // don't allow a local of param with a kind of let
-      (local.kind === "param" && (kind === "let" || kind === "const"));
+      (local.kind === "param" && kind === "const");
 
     if (duplicate) {
       throw this.hub.buildError(