.eslintrc

{
  // Configuration for JavaScript files
  "extends": [
    "airbnb-base",
    "next/core-web-vitals", // Needed to avoid warning in next.js build: 'The Next.js plugin was not detected in your ESLint configuration'
    "plugin:prettier/recommended"
  ],
  "rules": {
    "prettier/prettier": [
      "error",
      {
        "arrowParens": "always",
        "bracketSpacing": true,
        "endOfLine": "auto",
        "htmlWhitespaceSensitivity": "css",
        "insertPragma": false,
        "singleAttributePerLine": false,
        "bracketSameLine": false,
        "jsxBracketSameLine": false,
        "jsxSingleQuote": false,
        "printWidth": 80,
        "proseWrap": "preserve",
        "quoteProps": "as-needed",
        "requirePragma": false,
        "semi": true,
        "singleQuote": false,
        "tabWidth": 2,
        "trailingComma": "es5",
        "useTabs": false
      }
    ]
  },
  "overrides": [
    // Configuration for TypeScript files
    {
      "files": ["**/*.ts", "**/*.tsx"],
      "plugins": ["@typescript-eslint", "unused-imports", "simple-import-sort"],
      "extends": [
        "airbnb-typescript",
        "next/core-web-vitals",
        "plugin:prettier/recommended"
      ],
      "parser": "@typescript-eslint/parser",
      "parserOptions": {
        "project": ["./tsconfig.json"],
        "ecmaFeatures": {
          "jsx": true
        },
        "ecmaVersion": "latest",
        "sourceType": "module"
      },
      "rules": {
        "@next/next/no-img-element": "off", // Allow use of <img /> element
        "prefer-spread": "warn", // Prefer spread over Function.apply()
        "react/destructuring-assignment": "warn", // Prefer { val } = props instead of props.val
        "react/no-unknown-property": "warn", // No invalid prop passing, for ex, class instead of className
        "react/jsx-curly-brace-presence": "warn", // Do foo="bar" instead of foo={"bar"}
        "react/jsx-key": "warn", // Always provide a key while using .map() on jsx elements
        "no-plusplus": "off", // Use of unary ++ operator
        "no-param-reassign": "off", // Assignment to property of function parameters
        "react/require-default-props": "off", // Allow non-defined react props as undefined
        "react/jsx-props-no-spreading": "off", // _app.tsx uses spread operator and also, react-hook-form
        "react-hooks/exhaustive-deps": "off", // Incorrectly report needed dependency with Next.js router
        "@typescript-eslint/comma-dangle": "off", // Avoid conflict rule between Eslint and Prettier
        "@typescript-eslint/consistent-type-imports": "error", // Ensure `import type` is used when it's necessary
        "import/prefer-default-export": "off", // Named export is easier to refactor automatically
        "simple-import-sort/imports": "error", // Import configuration for `eslint-plugin-simple-import-sort`
        "simple-import-sort/exports": "error", // Export configuration for `eslint-plugin-simple-import-sort`
        "unused-imports/no-unused-imports": "error", // No import should remain unused
        "@typescript-eslint/no-unused-vars": "off", // Disable this so that the rule below can work
        "unused-imports/no-unused-vars": [
          "error",
          { "argsIgnorePattern": "^_" }
        ], // Don't allow unused vars but ignore ones starting with _
        "no-restricted-syntax": [
          "warn",
          {
            "selector": "CallExpression[callee.object.name='console'][callee.property.name!=/^(error)$/]",
            "message": "Unexpected property on console object was called"
          }
        ], // no console log/info/warning/etc
        "no-nested-ternary": "off" // to allow use of nested ternary expressions inside JSX
      }
    },
    // Configuration for testing
    {
      "files": ["**/*.test.ts", "**/*.test.tsx"],
      "plugins": ["jest", "jest-formatting", "testing-library", "jest-dom"],
      "extends": [
        "plugin:jest/recommended",
        "plugin:jest-formatting/recommended",
        "plugin:testing-library/react",
        "plugin:jest-dom/recommended"
      ]
    },
    // Configuration for e2e testing (Cypress)
    {
      "files": ["cypress/**/*.ts"],
      "plugins": ["cypress"],
      "extends": ["plugin:cypress/recommended"],
      "parserOptions": {
        "project": "./cypress/tsconfig.json"
      }
    }
  ]
}