I am currently setting up a boilerplate with React, TypeScript, styled components, Webpack, etc., and I am getting an error when trying to run ESLint:
Error: Must use import to load ES Module
Here is a more verbose version of the error:
/Users/ben/Desktop/development projects/react-boilerplate-styled-context/src/api/api.ts
0:0 error Parsing error: Must use import to load ES Module: /Users/ben/Desktop/development projects/react-boilerplate-styled-context/node_modules/eslint/node_modules/eslint-scope/lib/definition.js
require() of ES modules is not supported.
require() of /Users/ben/Desktop/development projects/react-boilerplate-styled-context/node_modules/eslint/node_modules/eslint-scope/lib/definition.js from /Users/ben/Desktop/development projects/react-boilerplate-styled-context/node_modules/babel-eslint/lib/require-from-eslint.js is an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which defines all .js files in that package scope as ES modules.
Instead rename definition.js to end in .cjs, change the requiring code to use import(), or remove "type": "module" from /Users/ben/Desktop/development projects/react-boilerplate-styled-context/node_modules/eslint/node_modules/eslint-scope/package.json
The error occurs in every single one of my .js and .ts/ .tsx files where I only use import
or the file doesn't even have an import at all. I understand what the error is saying, but I don't have any idea why it is being thrown when in fact I only use imports or even no imports at all in some files.
Here is my package.json file where I trigger the linter from using npm run lint:eslint:quiet
:
{
"name": "my-react-boilerplate",
"version": "1.0.0",
"description": "",
"main": "index.tsx",
"directories": {
"test": "test"
},
"engines": {
"node": ">=14.0.0"
},
"type": "module",
"scripts": {
"build": "webpack --config webpack.prod.js",
"dev": "webpack serve --config webpack.dev.js",
"lint": "npm run typecheck && npm run lint:css && npm run lint:eslint:quiet",
"lint:css": "stylelint './src/**/*.{js,ts,tsx}'",
"lint:eslint:quiet": "eslint --ext .ts,.tsx,.js,.jsx ./src --no-error-on-unmatched-pattern --quiet",
"lint:eslint": "eslint --ext .ts,.tsx,.js,.jsx ./src --no-error-on-unmatched-pattern",
"lint:eslint:fix": "eslint --ext .ts,.tsx,.js,.jsx ./src --no-error-on-unmatched-pattern --quiet --fix",
"test": "cross-env NODE_ENV=test jest --coverage",
"test:watch": "cross-env NODE_ENV=test jest --watchAll",
"typecheck": "tsc --noEmit",
"precommit": "npm run lint"
},
"lint-staged": {
"*.{ts,tsx,js,jsx}": [
"npm run lint:eslint:fix",
"git add --force"
],
"*.{md,json}": [
"prettier --write",
"git add --force"
]
},
"husky": {
"hooks": {
"pre-commit": "npx lint-staged && npm run typecheck"
}
},
"resolutions": {
"styled-components": "^5"
},
"author": "",
"license": "ISC",
"devDependencies": {
"@babel/core": "^7.5.4",
"@babel/plugin-proposal-class-properties": "^7.5.0",
"@babel/preset-env": "^7.5.4",
"@babel/preset-react": "^7.0.0",
"@types/history": "^4.7.6",
"@types/react": "^17.0.29",
"@types/react-dom": "^17.0.9",
"@types/react-router": "^5.1.17",
"@types/react-router-dom": "^5.1.5",
"@types/styled-components": "^5.1.15",
"@typescript-eslint/eslint-plugin": "^5.0.0",
"babel-cli": "^6.26.0",
"babel-eslint": "^10.0.2",
"babel-loader": "^8.0.0-beta.6",
"babel-polyfill": "^6.26.0",
"babel-preset-env": "^1.7.0",
"babel-preset-react": "^6.24.1",
"babel-preset-stage-2": "^6.24.1",
"clean-webpack-plugin": "^4.0.0",
"dotenv-webpack": "^7.0.3",
"error-overlay-webpack-plugin": "^1.0.0",
"eslint": "^8.0.0",
"eslint-config-airbnb": "^18.2.0",
"eslint-config-prettier": "^8.3.0",
"eslint-config-with-prettier": "^6.0.0",
"eslint-plugin-compat": "^3.3.0",
"eslint-plugin-import": "^2.25.2",
"eslint-plugin-jsx-a11y": "^6.2.3",
"eslint-plugin-prettier": "^4.0.0",
"eslint-plugin-react": "^7.14.2",
"eslint-plugin-react-hooks": "^4.2.0",
"extract-text-webpack-plugin": "^3.0.2",
"file-loader": "^6.2.0",
"html-webpack-plugin": "^5.3.2",
"husky": "^7.0.2",
"prettier": "^2.4.1",
"raw-loader": "^4.0.2",
"style-loader": "^3.3.0",
"stylelint": "^13.13.1",
"stylelint-config-recommended": "^5.0.0",
"stylelint-config-styled-components": "^0.1.1",
"stylelint-processor-styled-components": "^1.10.0",
"ts-loader": "^9.2.6",
"tslint": "^6.1.3",
"typescript": "^4.4.4",
"url-loader": "^4.1.1",
"webpack": "^5.58.2",
"webpack-cli": "^4.2.0",
"webpack-dev-server": "^4.3.1",
"webpack-merge": "^5.3.0"
},
"dependencies": {
"history": "^4.10.0",
"process": "^0.11.10",
"react": "^17.0.1",
"react-dom": "^17.0.1",
"react-router-dom": "^5.2.0",
"styled-components": "^5.2.1"
}
}
Here is my .eslintrc file:
{
"extends": ["airbnb", "prettier"],
"parser": "babel-eslint",
"plugins": ["prettier", "@typescript-eslint"],
"parserOptions": {
"ecmaVersion": 8,
"ecmaFeatures": {
"experimentalObjectRestSpread": true,
"impliedStrict": true,
"classes": true
}
},
"env": {
"browser": true,
"node": true,
"jest": true
},
"rules": {
"arrow-body-style": ["error", "as-needed"],
"class-methods-use-this": 0,
"react/jsx-filename-extension": 0,
"global-require": 0,
"react/destructuring-assignment": 0,
"import/named": 2,
"linebreak-style": 0,
"import/no-dynamic-require": 0,
"import/no-named-as-default": 0,
"import/no-unresolved": 2,
"import/prefer-default-export": 0,
"semi": [2, "always"],
"max-len": [
"error",
{
"code": 80,
"ignoreUrls": true,
"ignoreComments": true,
"ignoreStrings": true,
"ignoreTemplateLiterals": true
}
],
"new-cap": [
2,
{
"capIsNew": false,
"newIsCap": true
}
],
"no-param-reassign": 0,
"no-shadow": 0,
"no-tabs": 2,
"no-underscore-dangle": 0,
"react/forbid-prop-types": [
"error",
{
"forbid": ["any"]
}
],
"import/no-extraneous-dependencies": ["error", { "devDependencies": true }],
"react/jsx-no-bind": [
"error",
{
"ignoreRefs": true,
"allowArrowFunctions": true,
"allowBind": false
}
],
"react/no-unknown-property": [
2,
{
"ignore": ["itemscope", "itemtype", "itemprop"]
}
]
}
}
And I’m not sure if it is relevant, but here is also my tsconfig.eslint.json file:
{
"extends": "./tsconfig.json",
"include": ["./src/**/*.ts", "./src/**/*.tsx", "./src/**/*.js"],
"exclude": ["node_modules/**", "build/**", "coverage/**"]
}
How can I fix this?
Googling the error does not present any useful forums or raised bugs. Most of them just state not to use require
in your files which I am not.
Answers
The error you're encountering (Error: Must use import to load ES Module
) is likely due to a conflict between the different configurations and versions of dependencies in your project, especially related to ESLint and its parser and plugins. Here's a step-by-step approach to resolve the issue:
Step 1: Update Dependencies
First, ensure that all your dependencies are up to date. You can do this by updating your package.json
and reinstalling the dependencies.
Step 2: Use @typescript-eslint/parser
Since you are using TypeScript, it's better to use @typescript-eslint/parser
instead of babel-eslint
.
Step 3: Configure ESLint for TypeScript
Update your .eslintrc
to use the TypeScript parser and plugins.
Step 4: Ensure Consistent Module Type
Make sure your project configuration is consistent with your module type.
Here's how you can modify your setup:
- Update
.eslintrc
configuration:
{
"extends": [
"airbnb",
"plugin:@typescript-eslint/recommended",
"plugin:prettier/recommended"
],
"parser": "@typescript-eslint/parser",
"plugins": [
"@typescript-eslint",
"prettier",
"react",
"react-hooks",
"jsx-a11y",
"import"
],
"parserOptions": {
"ecmaVersion": 2020,
"sourceType": "module",
"ecmaFeatures": {
"jsx": true
}
},
"env": {
"browser": true,
"node": true,
"jest": true
},
"rules": {
"prettier/prettier": "error",
"arrow-body-style": ["error", "as-needed"],
"class-methods-use-this": 0,
"react/jsx-filename-extension": [1, { "extensions": [".js", ".jsx", ".ts", ".tsx"] }],
"global-require": 0,
"react/destructuring-assignment": 0,
"import/named": 2,
"linebreak-style": 0,
"import/no-dynamic-require": 0,
"import/no-named-as-default": 0,
"import/no-unresolved": 2,
"import/prefer-default-export": 0,
"semi": [2, "always"],
"max-len": [
"error",
{
"code": 80,
"ignoreUrls": true,
"ignoreComments": true,
"ignoreStrings": true,
"ignoreTemplateLiterals": true
}
],
"new-cap": [
2,
{
"capIsNew": false,
"newIsCap": true
}
],
"no-param-reassign": 0,
"no-shadow": 0,
"no-tabs": 2,
"no-underscore-dangle": 0,
"react/forbid-prop-types": [
"error",
{
"forbid": ["any"]
}
],
"import/no-extraneous-dependencies": ["error", { "devDependencies": true }],
"react/jsx-no-bind": [
"error",
{
"ignoreRefs": true,
"allowArrowFunctions": true,
"allowBind": false
}
],
"react/no-unknown-property": [
2,
{
"ignore": ["itemscope", "itemtype", "itemprop"]
}
]
},
"settings": {
"import/resolver": {
"node": {
"extensions": [".js", ".jsx", ".ts", ".tsx"]
}
}
}
}
- Update
package.json
scripts:
Ensure your package.json
scripts are set correctly to use ESLint with the TypeScript parser:
"scripts": {
"build": "webpack --config webpack.prod.js",
"dev": "webpack serve --config webpack.dev.js",
"lint": "npm run typecheck && npm run lint:css && npm run lint:eslint:quiet",
"lint:css": "stylelint './src/**/*.{js,ts,tsx}'",
"lint:eslint:quiet": "eslint --ext .ts,.tsx,.js,.jsx ./src --no-error-on-unmatched-pattern --quiet",
"lint:eslint": "eslint --ext .ts,.tsx,.js,.jsx ./src --no-error-on-unmatched-pattern",
"lint:eslint:fix": "eslint --ext .ts,.tsx,.js,.jsx ./src --no-error-on-unmatched-pattern --quiet --fix",
"test": "cross-env NODE_ENV=test jest --coverage",
"test:watch": "cross-env NODE_ENV=test jest --watchAll",
"typecheck": "tsc --noEmit",
"precommit": "npm run lint"
},
- Install Necessary ESLint Plugins:
Ensure you have the necessary ESLint plugins and parsers installed:
npm install @typescript-eslint/parser @typescript-eslint/eslint-plugin eslint-plugin-react eslint-plugin-react-hooks eslint-plugin-jsx-a11y eslint-plugin-import eslint-config-airbnb eslint-config-prettier eslint-plugin-prettier --save-dev
- Ensure Consistent Module Type:
If you are using ES modules (import/export
syntax), ensure your package.json
includes:
"type": "module",
If you are using CommonJS modules (require/module.exports
syntax), ensure type
is not set or set to "commonjs"
.
Conclusion
With these steps, you should have a consistent and functional ESLint setup for your React project using TypeScript. The key changes include using @typescript-eslint/parser
and updating the ESLint configuration accordingly. This should resolve the issue with loading ES modules.