Use correct scope in switch statements

package.json

@@ -143,9 +143,6 @@
     "weak-napi": "^2.0.2",
     "yargs-parser": "^21.1.1"
   },
-  "overrides": {
-    "d3": "7.8.0"
-  },
   "files": [
     "dist/**/*.js",
     "dist/*.d.ts",

src/ast/nodes/SwitchStatement.ts

@@ -6,19 +6,23 @@ import {
 	type InclusionContext
 } from '../ExecutionContext';
 import BlockScope from '../scopes/BlockScope';
+import type ChildScope from '../scopes/ChildScope';
 import type Scope from '../scopes/Scope';
 import type * as NodeType from './NodeType';
 import type SwitchCase from './SwitchCase';
-import { type ExpressionNode, type IncludeChildren, StatementBase } from './shared/Node';
+import type { ExpressionNode, GenericEsTreeNode, IncludeChildren } from './shared/Node';
+import { StatementBase } from './shared/Node';
 
 export default class SwitchStatement extends StatementBase {
 	declare cases: readonly SwitchCase[];
 	declare discriminant: ExpressionNode;
 	declare type: NodeType.tSwitchStatement;
 
 	private declare defaultCase: number | null;
+	private declare parentScope: ChildScope;
 
 	createScope(parentScope: Scope): void {
+		this.parentScope = parentScope as ChildScope;
 		this.scope = new BlockScope(parentScope);
 	}
 
@@ -89,6 +93,15 @@ export default class SwitchStatement extends StatementBase {
 		this.defaultCase = null;
 	}
 
+	parseNode(esTreeNode: GenericEsTreeNode) {
+		this.discriminant = new (this.context.getNodeConstructor(esTreeNode.discriminant.type))(
+			esTreeNode.discriminant,
+			this,
+			this.parentScope
+		);
+		super.parseNode(esTreeNode);
+	}
+
 	render(code: MagicString, options: RenderOptions): void {
 		this.discriminant.render(code, options);
 		if (this.cases.length > 0) {

test/function/samples/switch-scope/_config.js

@@ -0,0 +1,3 @@
+module.exports = defineTest({
+	description: 'uses correct scopes for switch statements'
+});

test/function/samples/switch-scope/main.js

@@ -0,0 +1,10 @@
+const foo = 1;
+let triggered = false;
+
+switch (foo) {
+	case 1:
+		const foo = 2;
+		triggered = true;
+}
+
+assert.ok(triggered);