Lint and formatting

Midway framework and business code is mainly written in TypeScript. By default, Midway uses mwts to keep linting and formatting consistent.

Code style package

mwts is Midway's TypeScript style toolkit, including:

• ESLint checking (check / lint)
• Auto fixes (fix)
• Default formatting setup (default: Prettier + ESLint)

mwts is inspired by gts, but it does not directly depend on the gts package.

info

In Midway projects, mwts is usually included by scaffolding. This page explains the configuration and migration flow.

Dependencies and runtime requirements

For mwts 2.x, the recommended baseline is:

{
  "engines": {
    "node": ">=20"
  },
  "devDependencies": {
    "mwts": "^2.0.0",
    "typescript": "^5.0.0"
  }
}

Init and migration

For new projects:

npx mwts init

For legacy mwts 1.x projects (.eslintrc.json based):

npx mwts migrate

After migration, eslint.config.js (ESLint Flat Config) will be generated.

ESLint config (mwts 2.x)

mwts 2.x uses eslint.config.js. A recommended setup is:

const mwtsConfig = require('mwts/eslint.config.js');

module.exports = [
  {
    ignores: ['**/node_modules', '**/dist'],
  },
  ...mwtsConfig,
];

If your project uses Jest, add Jest globals for test files:

const globals = require('globals');

module.exports = [
  ...require('mwts/eslint.config.js'),
  {
    files: ['**/*.test.ts', '**/*.spec.ts', '**/jest.setup.js'],
    languageOptions: {
      globals: {
        ...globals.jest,
      },
    },
  },
];

Run check and fix

Common scripts (usually already included):

{
  "scripts": {
    "lint": "mwts check",
    "lint:fix": "mwts fix"
  }
}

mwts check/lint/fix also support file arguments:

mwts check src/index.ts
mwts fix src/index.ts

Prettier config

In default mode, keep .prettierrc.js:

module.exports = {
  ...require('mwts/.prettierrc.json'),
};

Optional formatter modes

mwts init supports three modes:

• default: Prettier + ESLint
• --formatter stylistic: ESLint + Stylistic
• --formatter biome: Biome + ESLint

If you choose non-default mode, follow the generated config files.