fix(babel): fix backend.generate is not a function error in mjs build

Author: jedwards1211

package.json

@@ -29,7 +29,8 @@
     "types"
   ],
   "astx": {
-    "parser": "babel"
+    "parser": "babel",
+    "workers": 0
   },
   "main": "./cjs/index.js",
   "types": "./types/index.d.ts",

src/babel/BabelBackend.ts

@@ -3,7 +3,8 @@ import { Backend } from '../backend/Backend'
 import * as defaultParser from '@babel/parser'
 import { ParserOptions } from '@babel/parser'
 import * as defaultTypes from '@babel/types'
-import defaultGenerate from '@babel/generator'
+import babelGenerator from '@babel/generator'
+const defaultGenerate = (babelGenerator as any).default || babelGenerator
 import * as AstTypes from 'ast-types'
 import babelAstTypes from './babelAstTypes'
 import { Comment, Location } from '../types'

src/babel/getBabelAutoBackend.ts

@@ -27,11 +27,12 @@ export default async function getBabelAutoBackend(
   options?: { [k in string]?: any }
 ): Promise<BabelBackend> {
   const basedir = path.dirname(file)
-  const [_parser, types, { default: generate }]: any = await Promise.all([
+  const [_parser, types, { default: _generate }]: any = await Promise.all([
     getParserAsync(file, options),
     importLocal('@babel/types', basedir),
     importLocal('@babel/generator', basedir),
   ])
+  const generate = _generate.default || _generate
   const parser = _parser.parserOpts.sourceType
     ? _parser
     : _parser.bindParserOpts({ sourceType: 'unambiguous' })