From 109f48818f51197291ea73c435b32acd7db930fa Mon Sep 17 00:00:00 2001
From: liuxingbaoyu <30521560+liuxingbaoyu@users.noreply.github.com>
Date: Fri, 2 Sep 2022 23:59:00 +0800
Subject: [PATCH] fix and improve

---
 .../babel-parser/src/plugins/typescript/index.ts |  4 ++--
 .../babel-parser/src/plugins/typescript/scope.ts | 16 ++++++----------
 packages/babel-parser/src/util/scope.ts          |  2 +-
 packages/babel-parser/src/util/scopeflags.ts     |  3 +--
 4 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/packages/babel-parser/src/plugins/typescript/index.ts b/packages/babel-parser/src/plugins/typescript/index.ts
index 2ddb794afe01..44418d140f7b 100644
--- a/packages/babel-parser/src/plugins/typescript/index.ts
+++ b/packages/babel-parser/src/plugins/typescript/index.ts
@@ -20,7 +20,7 @@ import type Parser from "../../parser";
 import {
   type BindingTypes,
   SCOPE_TS_MODULE,
-  SCOPE_TS_TOP_LEVEL,
+  SCOPE_OTHER,
   BIND_TS_ENUM,
   BIND_TS_CONST_ENUM,
   BIND_TS_TYPE,
@@ -1862,7 +1862,7 @@ export default (superClass: ClassWithMixin<typeof Parser, IJSXParserMixin>) =>
 
     tsParseModuleBlock(): N.TsModuleBlock {
       const node = this.startNode<N.TsModuleBlock>();
-      this.scope.enter(SCOPE_TS_TOP_LEVEL);
+      this.scope.enter(SCOPE_OTHER);
 
       this.expect(tt.braceL);
       // Inside of a module block is considered "top-level", meaning it can have imports and exports.
diff --git a/packages/babel-parser/src/plugins/typescript/scope.ts b/packages/babel-parser/src/plugins/typescript/scope.ts
index b7669ffe9a30..f52addec598f 100644
--- a/packages/babel-parser/src/plugins/typescript/scope.ts
+++ b/packages/babel-parser/src/plugins/typescript/scope.ts
@@ -11,7 +11,6 @@ import {
   type BindingTypes,
   BIND_FLAGS_TS_IMPORT,
   SCOPE_TS_MODULE,
-  SCOPE_TS_TOP_LEVEL,
 } from "../../util/scopeflags";
 import type * as N from "../../types";
 import { Errors } from "../../parse-error";
@@ -48,30 +47,27 @@ export default class TypeScriptScopeHandler extends ScopeHandler<TypeScriptScope
   }
 
   enter(flags: number): void {
-    if (flags == SCOPE_TS_MODULE || flags == SCOPE_TS_TOP_LEVEL) {
+    if (flags == SCOPE_TS_MODULE) {
       this.importsStack.push(new Set());
     }
 
     super.enter(flags);
   }
 
-  exit(): ScopeFlags {
+  exit() {
     const flags = super.exit();
 
-    if (flags == SCOPE_TS_MODULE || flags == SCOPE_TS_TOP_LEVEL) {
+    if (flags == SCOPE_TS_MODULE) {
       this.importsStack.pop();
     }
-
-    return flags;
   }
 
   hasImport(name: string, allowShadow?: boolean) {
     const len = this.importsStack.length;
-    if (!this.importsStack[len - 1].has(name)) {
-      return !allowShadow && len > 2 && this.importsStack[0].has(name);
+    if (this.importsStack[len - 1].has(name)) {
+      return true;
     }
-
-    return true;
+    return !allowShadow && len > 1 && this.importsStack[0].has(name);
   }
 
   declareName(name: string, bindingType: BindingTypes, loc: Position) {
diff --git a/packages/babel-parser/src/util/scope.ts b/packages/babel-parser/src/util/scope.ts
index 94277cbaf603..b90137c00ad0 100644
--- a/packages/babel-parser/src/util/scope.ts
+++ b/packages/babel-parser/src/util/scope.ts
@@ -93,7 +93,7 @@ export default class ScopeHandler<IScope extends Scope = Scope> {
     this.scopeStack.push(this.createScope(flags));
   }
 
-  exit(): ScopeFlags {
+  exit(): ScopeFlags | void {
     const scope = this.scopeStack.pop();
     return scope.flags;
   }
diff --git a/packages/babel-parser/src/util/scopeflags.ts b/packages/babel-parser/src/util/scopeflags.ts
index 52e0eba7da6d..73b8dbeb1a70 100644
--- a/packages/babel-parser/src/util/scopeflags.ts
+++ b/packages/babel-parser/src/util/scopeflags.ts
@@ -10,8 +10,7 @@ export const SCOPE_OTHER        = 0b000000000,
              SCOPE_CLASS        = 0b001000000,
              SCOPE_STATIC_BLOCK = 0b010000000,
              SCOPE_TS_MODULE    = 0b100000000,
-             SCOPE_VAR = SCOPE_PROGRAM | SCOPE_FUNCTION | SCOPE_TS_MODULE,
-             SCOPE_TS_TOP_LEVEL = 0b1000000000;
+             SCOPE_VAR = SCOPE_PROGRAM | SCOPE_FUNCTION | SCOPE_TS_MODULE;
 
 export type ScopeFlags =
   | typeof SCOPE_OTHER