Fix @babel/traverse import to work in non ESM environments (#787)

Author: danez

.changeset/seven-plants-occur.md

@@ -0,0 +1,5 @@
+---
+'react-docgen': patch
+---
+
+Fix @babel/traverse import to work in non ESM environments

packages/react-docgen/src/FileState.ts

@@ -1,10 +1,13 @@
 import type { HubInterface, Scope, Visitor } from '@babel/traverse';
-import traverse, { NodePath } from '@babel/traverse';
+import babelTraverse, { NodePath } from '@babel/traverse';
 import type { File, Node, Program } from '@babel/types';
 import type { Importer, ImportPath } from './importer/index.js';
 import babelParse from './babelParser.js';
 import type { TransformOptions } from '@babel/core';
 
+// Workaround while babel is not a proper ES module
+const traverse = babelTraverse.default ?? babelTraverse;
+
 export default class FileState {
   opts: TransformOptions;
   path: NodePath<Program>;
@@ -85,6 +88,6 @@ export default class FileState {
    * Traverse the current file
    */
   traverse(visitors: Visitor, state?: unknown): void {
-    traverse.default(this.ast, visitors, this.scope, state);
+    traverse(this.ast, visitors, this.scope, state);
   }
 }