3. Upgrade ESLint and Prettier

Update ESLint and Prettier setup

The "Update ESLint and Prettier setup" patch will update your existing ESLint config and Prettier config files to use the new base configuration shipped with v6 apps.

If you are using a custom setup for both ESLint and Prettier, then you can skip patch. However, then you will have manually update eslint and its plugins and ensure they work smoothly with an ESM application.

npx @adonisjs/upgrade-kit@latest upgrade-eslint-prettier

Following are the steps performed by this patch.

Config files removed

  • Remove eslintrc.json and .eslintignore files. The new config will be inline within the package.json file.
  • Remove .prettierrc file. The new config will be inline within the package.json file.

Packages upgraded

  • eslint
  • prettier

Packages removed

The following packages have been removed in favour of a single base configuration package @adonisjs/eslint-config.

  • eslint-config-prettier
  • eslint-plugin-adonis
  • eslint-plugin-prettier

Newly added packages

  • @adonisjs/eslint-config - Contains base rules for ESLint and ensure it works great with TypeScript, ESM, and Prettier.
  • @adonisjs/prettier-config - Contains base configuration for prettier rules we are using with v6 apps.

Temporary rules

We disable the following ESLint rules temporarily to make migration from v5 -> v6 smoother.

"rules": {
"@typescript-eslint/explicit-member-accessibility": "off",
"unicorn/filename-case": "off",
"@typescript-eslint/no-shadow": "off"
  • @typescript-eslint/explicit-member-accessibility: In v6 we no longer use TypeScript class property modifiers like public, or private. Instead we use JavaScript native private properties prefixed with a #.

    However, removing property modifiers from an entire codebase can be a tedious task and therefore we turn off this rule temporarily. If needed, you can turn it back on after the migration is completed and your app is in working state.

  • unicorn/filename-case: In v6, we opted for a snake_case naming convention for the naming folders and files. Again, to make migration smooth, we turn off the ESLint rule.

  • @typescript-eslint/no-shadow is a newly added rule and might force you to refactor your application codebase. We turn off this rule to make migration process smooth.