When I try running any command in Sequelize, inside or outside the docker container, that needs the configuration file (In my case, config.mjs), I get this error:

ERROR: Error reading "build/database/config/config.mjs". Error: Error [ERR_REQUIRE_ESM]: require() of ES Module /backend/build/database/config/config.mjs not supported. Instead change the require of /backend/build/database/config/config.mjs to a dynamic import() which is available in all CommonJS modules.

Sometimes, it mentions Instead change the require of config.js in /backend/node_modules/sequelize-cli/lib/helpers/config-helper.js, which points to the lib itself.

I tried changing config.mjs to CommonJs using require instead of import, but that creates a cascade of files not being able to import it and thus having to be converted to CommonJS, such as the index.js in the models folder, that would give me this error:

File '/home/giovani/Projetos/GiovaniJogos/backend/src/database/config/config.ts' is not a module.

All these files are already transpiled from Typescript, in the build folder.

I’m using .mjs instead of .js because config.js was not being treated as a module. I used it instead of setting "type": "module" in package.json to see if it solved the problem, it didn’t.

This is my config.mts (before transpilation):

import { type Options } from 'sequelize'

const config: Options = {
  username: process.env.MYSQL_USER,
  password: process.env.MYSQL_PASSWORD,
  database: process.env.MYSQL_DATABASE,
  host: process.env.MYSQL_HOST,
  port: Number(process.env.MYSQL_PORT),
  dialect: 'mysql'
}

module.exports = config

This is my index.ts:

import { Sequelize } from 'sequelize'
import * as config from '../config/config.mjs'

export default new Sequelize(config)

This is my tsconfig.json:

{ "compilerOptions": { "target": "ES6", "module": "ES6", "sourceMap": true, "outDir": "./build", "rootDir": "./src", "strict": true, "moduleResolution": "node", "baseUrl": ".", "forceConsistentCasingInFileNames": true, "resolveJsonModule": true, "experimentalDecorators": true, "emitDecoratorMetadata": true, "strictPropertyInitialization": false, "esModuleInterop": true, "allowSyntheticDefaultImports": true, "skipLibCheck": true, "paths": { "*": ["node_modules/*"] } }, "include": ["src/**/*"], }

These are my packages versions:

"sequelize-cli": "^6.3.0",
"ts-node": "^10.9.1",
"ts-node-dev": "^2.0.0",
"typescript": "^5.3.3",
"sequelize": "^6.9.0"
"mysql2": "^3.0.0"

Node: 20.12.2

• Tried changing target and module properties to many different combinations.
• Tried removing the module property.
• Tried, as I said, setting "type": "module" in package.json.
• Tried placing a package.json inside the config folder with just {"type": "commonjs"}, as I saw suggested in some posts.
• Tried the instructions in this post, which makes the same cascade I mentioned before.

I always get the [ERR_REQUIRE_ESM] error or the SyntaxError: Cannot use import statement outside a module if I don’t convert it to a module with the .mts extension or the package.json configuration.

I’m perplexed since this is a very basic configuration and worked just fine, with these EXACT config.ts and index.ts files, in 3 tutorials I read.