.eslintrc.json

{
	"root": true,
	"parser": "@babel/eslint-parser",
	"plugins": ["react", "react-hooks", "jest", "import"],
	"env": {
		"browser": true,
		"commonjs": true,
		"es6": true,
		"node": true
	},
	"parserOptions": {
		"requireConfigFile": false,
		"sourceType": "module",
		"ecmaFeatures": {
			"jsx": true
		},
		"babelOptions": {
			"presets": ["@babel/preset-react"]
		}
	},
	"settings": {
		"react": {
			"version": "detect"
		},
		"import/internal-regex": "^next/"
	},
	"overrides": [
		{
			"files": ["test/**/*.js", "test/**/*.ts", "**/*.test.ts"],
			"extends": ["plugin:jest/recommended"],
			"rules": {
				"jest/expect-expect": "off",
				"jest/no-disabled-tests": "off",
				"jest/no-conditional-expect": "off",
				"jest/valid-title": "off",
				"jest/no-interpolation-in-snapshots": "off",
				"jest/no-export": "off"
			}
		},
		{
			"files": ["docs-site/*.ts", "docs-site/*.tsx", "docs-site/*.md", "docs-site/*.mdx"],
			"extends": ["plugin:mdx/recommended"],
			"settings": {
				"mdx/code-blocks": true,
				"mdx/language-mapper": {}
			}
		},
		{ "files": ["**/__tests__/**"], "env": { "jest": true } },
		{
			"files": ["**/*.ts", "**/*.tsx"],
			"parser": "@typescript-eslint/parser",
			"parserOptions": {
				"ecmaVersion": 2018,
				"sourceType": "module",
				"ecmaFeatures": {
					"jsx": true
				},
				"warnOnUnsupportedTypeScriptVersion": false
			},
			"plugins": ["@typescript-eslint"],
			"rules": {
				// Already handled by TS
				"no-dupe-class-members": "off",
				"no-undef": "off",

				// Add TypeScript specific rules (and turn off ESLint equivalents)
				"@typescript-eslint/consistent-type-assertions": "warn",
				"no-array-constructor": "off",
				"@typescript-eslint/no-array-constructor": "warn",
				"@typescript-eslint/no-namespace": "error",
				"no-use-before-define": "off",
				"@typescript-eslint/no-use-before-define": "off",
				"no-unused-vars": "off",
				"@typescript-eslint/no-unused-vars": [
					"warn",
					{
						"args": "none",
						"ignoreRestSiblings": true
					}
				],
				"no-unused-expressions": "off",
				"@typescript-eslint/no-unused-expressions": [
					"error",
					{
						"allowShortCircuit": true,
						"allowTernary": true,
						"allowTaggedTemplates": true
					}
				],
				"no-useless-constructor": "off",
				"@typescript-eslint/no-useless-constructor": "warn",
				"@typescript-eslint/prefer-literal-enum-member": "error",
				"@typescript-eslint/prefer-namespace-keyword": "error"
			}
		},
		{
			"files": ["test/**/*", "examples/**/*", "packages/create-next-app/templates/**/*"],
			"rules": { "react/react-in-jsx-scope": "off" }
		},
		{
			"files": ["examples/**/*"],
			"rules": {
				"@typescript-eslint/no-use-before-define": "off",
				"import/no-anonymous-default-export": [
					"error",
					{
						// React components:
						"allowArrowFunction": false,
						"allowAnonymousClass": false,
						"allowAnonymousFunction": false,

						// Non-React stuff:
						"allowArray": true,
						"allowCallExpression": true,
						"allowLiteral": true,
						"allowObject": true
					}
				]
			}
		},
		{
			"files": ["packages/**"],
			"rules": {
				"no-shadow": ["warn", { "builtinGlobals": false }],
				"import/no-extraneous-dependencies": ["error", { "devDependencies": false }]
			}
		},
		{
			"files": ["packages/**/*.tsx", "packages/**/*.ts"],
			"rules": {
				"@typescript-eslint/no-unused-vars": [
					"warn",
					{
						"args": "all",
						"argsIgnorePattern": "^_",
						"ignoreRestSiblings": true
					}
				]
			}
		},
		{
			"files": ["packages/eslint-plugin-next/**/*.js", "test/unit/eslint-plugin-next/**/*.test.ts"],
			"extends": ["plugin:eslint-plugin/recommended"],
			"parserOptions": {
				"sourceType": "script"
			},
			"rules": {
				"eslint-plugin/prefer-replace-text": "error",
				"eslint-plugin/report-message-format": ["error", ".+\\. See: https://nextjs.org/docs/messages/[a-z\\-]+$"],
				"eslint-plugin/require-meta-docs-description": [
					"error",
					{
						"pattern": ".+"
					}
				],
				"eslint-plugin/require-meta-docs-url": "error"
			}
		}
	]
}