TypeError: Cannot redefine property: default

[zhinanchendd01]

TypeScript Version: 3.9.3

Code

file1.js

module.exports = {
  default: {
    log() {
    }
  },
}

file2.ts

import file1 from './file1'
file1.log()

Actual behavior:

TypeError: Cannot redefine property: default

Related Issues: #38552

[joeldenning]

This is likely a duplicate of #38540

[weswigham]

I actually can't reproduce the issue in the OP - @zhinanchendd01 is there more context to this? Or a specific set of compiler options? I've tried both with and without esModuleInterop on, and can't replicate your result.

[malord]

I just had this with TypeScript 3.9.3. This is my tsconfig.json:

{
  "compilerOptions": {
    "target": "es2018",
    "module": "commonjs",
    "outDir": "./lib",
    "rootDir": "./src",
    "strict": true,
    "esModuleInterop": true
  },
  "exclude": [
    "test"
  ]
}

I found out that this fails:

import sequelize, { Op, Sequelize } from 'sequelize';

But this works:

import { Op, Sequelize } from 'sequelize';  
import sequelize from 'sequelize';

[Johnvict]

I just had this with TypeScript 3.9.3. This is my tsconfig.json:

{
  "compilerOptions": {
    "target": "es2018",
    "module": "commonjs",
    "outDir": "./lib",
    "rootDir": "./src",
    "strict": true,
    "esModuleInterop": true
  },
  "exclude": [
    "test"
  ]
}

I found out that this fails:

import sequelize, { Op, Sequelize } from 'sequelize';

But this works:

import { Op, Sequelize } from 'sequelize';  
import sequelize from 'sequelize';

This solved the whole thing.. Thank you

[aecorredor]

Same exact thing is happening to me with sequelize right after going from 3.8.3 to 3.9.3. Is this expected or is it a regression?

[aecorredor]

Just saw there's a fix already in #38540

[zhinanchendd01]

my tsconfig.json

{
	"compileOnSave": true,
	"compilerOptions": {
		"target": "es2018",
		"module": "commonjs",
		"esModuleInterop": true,
		"outDir": "dist",
		"baseUrl": "src",
	},
	"exclude": ["dist", "node_modules"]
}

logger.js

const info = (...args) => {
  console.log(...args)
}

const debug = (...args) => {
  console.debug(...args)
}

module.exports = { info, debug }

module.exports.default = { info, debug }

index.ts

this failed:

import * as logger from './logger'
logger.debug('debug 1')
// TypeError: Cannot redefine property: default

this can work:

import logger from './logger'
logger.debug('debug 1')

@weswigham

[zhinanchendd01]

logger.js

const info = (...args) => {
  console.log(...args)
}

const debug = (...args) => {
  console.debug(...args)
}

module.exports.default = { info, debug }

index.ts

import logger from './logger'
logger.info('info')
// TypeError: logger_1.default.info is not a function

console.log(logger)
// { default: { info: [Function: info], debug: [Function: debug] } }

[kherock]

This actually appears to be fixed for my code in v3.9.4, but it's not currently published to npm with the latest tag.

[MaciekBaron]

But this works:

import { Op, Sequelize } from 'sequelize';  
import sequelize from 'sequelize';

I have exactly the same issue – for some reason I cannot write:

import parse, { domToReact } from 'html-react-parser';

I have to split it into two lines.

EDIT: Seems to be fixed when using [email protected]

[alansoliditydev]

This helps me.

    "typescript": "3.9.7",
    "tslib": "1.13.0"