TypeError when using CommonJS: XMLParser is not a constructor

[tbouffard]

• Are you running the latest version? 5.0.2
• Have you included sample input, output, error, and expected output?
• Have you checked if you are using correct configuration? Take the example from the readme
• Did you try online tool?
• Have you checked the docs for helpful APIs and examples?

Description

When using CommonJS, my application is unable to create an instance of XMLParser or XMLBuilder
I get errors like TypeError: XMLParser is not a constructor when running with node or when running tests with Jest TypeError: fast_xml_parser_1.XMLParser is not a constructor
I have the same kind of error when trying to use XMLBuilder

For example (run on Ubuntu 22.04, node v20.18.3)

$ node parse.cjs
/dev/bump_fxp_v5_poc/repro_commonjs_pb/parse.cjs:15
const parser = new XMLParser();
               ^

TypeError: XMLParser is not a constructor
    at Object.<anonymous> (/dev/bump_fxp_v5_poc/repro_commonjs_pb/parse.cjs:15:16)
    at Module._compile (node:internal/modules/cjs/loader:1469:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1548:10)
    at Module.load (node:internal/modules/cjs/loader:1288:32)
    at Module._load (node:internal/modules/cjs/loader:1104:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:173:12)
    at node:internal/main/run_main_module:28:49

Input

Here are scripts to reproduce the problem. I run them in a fresh project with a single dependency to fast-xml-parser

Code

CommonJS: not working

const { XMLParser, XMLBuilder } = require('fast-xml-parser');

const xml = `<?xml version="1.0"?>
<any_name>
    <person>
        <phone>+122233344550</phone>
        <name>Jack</name>
    </person>
    <person>
        <phone>+122233344553</phone>
        <name>Boris</name>
    </person>
</any_name>`;

const parser = new XMLParser();
const parsedObject = parser.parse(xml);
console.log('parsedObject', JSON.stringify(parsedObject, null, 2));

const builder = new XMLBuilder();
const xmlContent = builder.build({ note: 'hello' });
console.log('xmlContent', xmlContent);

ESM: working

import { XMLParser, XMLBuilder } from 'fast-xml-parser';

const xml = `<?xml version="1.0"?>
<any_name>
    <person>
        <phone>+122233344550</phone>
        <name>Jack</name>
    </person>
    <person>
        <phone>+122233344553</phone>
        <name>Boris</name>
    </person>
</any_name>`;

const parser = new XMLParser();
const parsedObject = parser.parse(xml);
console.log('parsedObject', JSON.stringify(parsedObject, null, 2));

const builder = new XMLBuilder();
const xmlContent = builder.build({ note: 'hello' });
console.log('xmlContent', xmlContent);

Output

CommonJS: see description at the top of this issue

expected data

Same as ESM:

$ node parse.mjs 
parsedObject {
  "?xml": "",
  "any_name": {
    "person": [
      {
        "phone": 122233344550,
        "name": "Jack"
      },
      {
        "phone": 122233344553,
        "name": "Boris"
      }
    ]
  }
}
xmlContent <note>hello</note>

Would you like to work on this issue?

• Yes
• No, but I can help by testing PR

[JakobMe]

I have the same issue using v5 with Jest. The culprit seems to be this line in lib/fxp.cjs:

/******/  module.exports.fxp = __webpack_exports__;

It should actually be module.exports = __webpack_exports__; to work properly, otherwise you get

{
  fxp: Object [Module] {
    XMLBuilder: [Getter],
    XMLParser: [Getter],
    XMLValidator: [Getter]
  }
}

by importing it.

[amitguptagwl]

issue is resolved will be publishing the changes soon

[amitguptagwl]

done, please reopen if you still find the issue.

[tbouffard]

ℹ I have tested 5.0.4 with the CommonJS script provided in this issue: no more error 🎉