frontend/eslint.config.mjs

import react from "@eslint-react/eslint-plugin";
import js from "@eslint/js";
import stylistic from "@stylistic/eslint-plugin";
import query from "@tanstack/eslint-plugin-query";
import vitest from "@vitest/eslint-plugin";
import { createTypeScriptImportResolver } from "eslint-import-resolver-typescript";
import { importX } from "eslint-plugin-import-x";
import jestDom from "eslint-plugin-jest-dom";
import perfectionist from "eslint-plugin-perfectionist";
import hooks from "eslint-plugin-react-hooks";
import refresh from "eslint-plugin-react-refresh";
import regexp from "eslint-plugin-regexp";
import security from "eslint-plugin-security";
import sonarjs from "eslint-plugin-sonarjs";
import storybook from "eslint-plugin-storybook";
import testingLibrary from "eslint-plugin-testing-library";
import unicorn from "eslint-plugin-unicorn";
import { defineConfig, globalIgnores } from "eslint/config";
import globals from "globals";
import tseslint from "typescript-eslint";

export default defineConfig(
	globalIgnores([
		"**/dist/**", "dist-ssr/**", "storybook-static/**", "coverage/**",
		".vitest/**", ".scannerwork/**", "src/shared/api/generated/**", "src/shared/api/spec/**",
	]),
	{
		extends: [
			js.configs.recommended,
			importX.flatConfigs.recommended,
			unicorn.configs.recommended,
			sonarjs.configs.recommended,
			regexp.configs.recommended,
			security.configs.recommended,
			perfectionist.configs["recommended-natural"],
			stylistic.configs.customize({ indent: "tab", jsx: true, quotes: "double", semi: true }),
		],
		files: ["**/*.{js,mjs,cjs,ts,tsx}"],
		linterOptions: { reportUnusedDisableDirectives: "error" },
		rules: {
			// A comma disambiguates generic arrow functions from JSX in TSX.
			"@stylistic/comma-dangle": ["error", {
				arrays: "always-multiline", enums: "always-multiline", exports: "always-multiline",
				functions: "always-multiline", generics: "ignore", imports: "always-multiline",
				objects: "always-multiline", tuples: "always-multiline",
			}],
			// Keep text/interpolation together: splitting can change rendered whitespace.
			"@stylistic/jsx-one-expression-per-line": ["error", { allow: "non-jsx" }],
			"@stylistic/no-tabs": ["error", { allowIndentationTabs: true }],
			"perfectionist/sort-classes": ["error", { groups: ["static-method", "property", "method", "unknown"], type: "natural" }],
			// Preserve the repository's component, hook and config file naming conventions.
			"unicorn/filename-case": ["error", { cases: { camelCase: true, kebabCase: true, pascalCase: true } }],
			// React uses Props/Ref names, including the recommended React ref-name rule.
			"unicorn/name-replacements": ["error", { replacements: { props: false, ref: false } }],
			// React, Mantine and Fetch accept null at their documented call boundaries.
			"unicorn/no-null": ["error", { checkArguments: false }],
		},
		settings: {
			"import-x/resolver-next": [createTypeScriptImportResolver({ project: "tsconfig.json" })],
		},
	},
	{
		files: ["**/*.{js,mjs,cjs}", "**/*.config.ts", ".storybook/main.ts"],
		languageOptions: { globals: globals.node },
	},
	{
		extends: [tseslint.configs.recommendedTypeChecked, importX.flatConfigs.typescript],
		files: ["**/*.{ts,tsx}"],
		languageOptions: { parserOptions: { projectService: true, tsconfigRootDir: import.meta.dirname } },
		rules: {
			// React ignores event handler return values; floating promises are still checked in bodies.
			"@typescript-eslint/no-misused-promises": ["error", { checksVoidReturn: { attributes: false } }],
			"@typescript-eslint/switch-exhaustiveness-check": "error",
		},
	},
	{
		extends: [react.configs["recommended-type-checked"], hooks.configs.flat.recommended, query.configs["flat/recommended"]],
		files: ["src/**/*.{ts,tsx}", "packages/*/src/**/*.{ts,tsx}", ".storybook/preview.tsx"],
		languageOptions: { globals: globals.browser },
		rules: {
			"import-x/exports-last": "error",
			"import-x/no-default-export": "error",
		},
	},
	{
		extends: [refresh.configs.vite],
		files: ["src/**/*.tsx", "packages/*/src/**/*.tsx"],
		ignores: ["**/*.test.tsx", "**/*.stories.tsx", "src/test/**"],
	},
	{
		files: ["src/**/*.{ts,tsx}", "packages/*/src/**/*.{ts,tsx}"],
		ignores: ["**/*.test.{ts,tsx}", "**/*.stories.tsx", "src/test/**"],
		rules: {
			"@typescript-eslint/no-magic-numbers": ["error", {
				ignore: [-1, 0, 1, "-1n", "0n", "1n"], ignoreArrayIndexes: true, ignoreDefaultValues: true,
				ignoreNumericLiteralTypes: true, ignoreTypeIndexes: true,
			}],
		},
	},
	{
		extends: [vitest.configs.recommended],
		files: ["**/*.test.{ts,tsx}"],
		rules: {
			"vitest/no-focused-tests": "error",
			"vitest/valid-expect": ["error", { maxArgs: 2 }],
		},
	},
	{
		extends: [testingLibrary.configs["flat/react"], jestDom.configs["flat/recommended"]],
		files: ["**/*.test.tsx"],
	},
	storybook.configs["flat/recommended"],
	{
		files: ["**/*.stories.tsx", ".storybook/preview.tsx"],
		rules: { "import-x/exports-last": "off", "import-x/no-default-export": "off" },
	},
);