.eslintrc

{
  "root": true,
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "project": "./tsconfig.json",
    "ecmaFeatures": {
      "jsx": true
    },
    "ecmaVersion": "latest",
    "sourceType": "module"
  },
  "settings": {
    "react": {
      "version": "detect"
    },
    // ! NB: empty object is intentional, mitigates module alias issue
    "import/resolver": {
      "typescript": {}
    }
  },
  "env": {
    "browser": true,
    "es2021": true,
    "jest": true
  },
  "extends": [
    "plugin:@typescript-eslint/recommended",
    "plugin:import/recommended",
    "plugin:import/typescript",
    "plugin:jest/recommended",
    "plugin:jest-dom/recommended",
    "plugin:react/recommended",
    "plugin:react-hooks/recommended",
    "plugin:storybook/recommended",
    "plugin:testing-library/react",
    "prettier"
  ],
  "plugins": [
    "@typescript-eslint",
    "react",
    "import",
    "typescript-sort-keys",
    "unused-imports",
    "prefer-arrow",
    "react-hooks",
    "jest",
    "jest-dom",
    "testing-library"
  ],
  "rules": {
    // allow non-null assertion operators
    "@typescript-eslint/no-non-null-assertion": "off",
    // allow empty object types (e.g. for interfaces)
    "@typescript-eslint/no-empty-object-type": "off",
    "@typescript-eslint/ban-ts-comment": [
      "error",
      // allow TypeScript bypass directives if a description is specified
      {
        "ts-ignore": "allow-with-description",
        "ts-nocheck": "allow-with-description"
      }
    ],
    // disallow unused variables
    "no-unused-vars": "off",
    "@typescript-eslint/no-unused-vars": [
      "error",
      {
        "varsIgnorePattern": "^_",
        "argsIgnorePattern": "^_"
      }
    ],
    "@typescript-eslint/no-unused-expressions": [
      "error",
      {
        "allowShortCircuit": true,
        "allowTernary": true
      }
    ],
    // suppress errors for missing React import (prefer modern JSX transform)
    "react/react-in-jsx-scope": "off",
    // prevent multiple components per file
    // NB: this rule is disabled because it is not compatible with the structure of our library
    // "react/no-multi-comp": "error",
    // enforce arrow functions for React components
    "react/function-component-definition": [
      "error",
      {
        "namedComponents": "arrow-function",
        "unnamedComponents": "arrow-function"
      }
    ],
    // warn on use of type `any`
    "@typescript-eslint/no-explicit-any": "warn",
    // explicitly handle promises (e.g. `await`, `void`)
    "@typescript-eslint/no-floating-promises": "error",
    // enforce type imports
    "@typescript-eslint/consistent-type-imports": "error",
    // prevent cyclic dependencies
    "import/no-cycle": "error",
    // prevent duplicate imports
    "import/no-duplicates": "error",
    // remove unused imports
    "unused-imports/no-unused-imports": "warn",
    // enforce import group order
    "import/order": [
      "error",
      {
        "alphabetize": {
          "caseInsensitive": true,
          "order": "asc"
        },
        // separate import groups (e.g. external dependencies from internal dependencies)
        "groups": [
          "builtin",
          "external",
          [
            "internal",
            // NB: TS aliased paths fall into `unknown` category. See https://github.com/import-js/eslint-plugin-import/issues/1379
            "unknown",
            "parent",
            "sibling",
            "index",
            "object"
          ],
          "type"
        ],
        "newlines-between": "always"
      }
    ]
  }
}