frontend/eslint.config.mjs

import js from "@eslint/js";
import react from "@eslint-react/eslint-plugin";
import query from "@tanstack/eslint-plugin-query";
import vitest from "@vitest/eslint-plugin";
import { defineConfig, globalIgnores } from "eslint/config";
import { importX } from "eslint-plugin-import-x";
import hooks from "eslint-plugin-react-hooks";
import refresh from "eslint-plugin-react-refresh";
import storybook from "eslint-plugin-storybook";
import testingLibrary from "eslint-plugin-testing-library";
import unicorn from "eslint-plugin-unicorn";
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/**",
	]),
	{
		files: ["**/*.{js,mjs,cjs,ts,tsx}"],
		extends: [js.configs.recommended],
		linterOptions: { reportUnusedDisableDirectives: "error" },
	},
	{
		files: ["**/*.{js,mjs,cjs}", "**/*.config.ts", ".storybook/main.ts"],
		languageOptions: { globals: globals.node },
	},
	{
		files: ["**/*.{ts,tsx}"],
		extends: [tseslint.configs.recommendedTypeChecked],
		languageOptions: {
			parserOptions: {
				projectService: true,
				tsconfigRootDir: import.meta.dirname,
			},
		},
		rules: {
			"@typescript-eslint/switch-exhaustiveness-check": "error",
			// React ignores handler return values; their bodies still check floating promises.
			"@typescript-eslint/no-misused-promises": [
				"error",
				{ checksVoidReturn: { attributes: false } },
			],
		},
	},
	{
		files: [
			"src/**/*.{ts,tsx}",
			"packages/*/src/**/*.{ts,tsx}",
			".storybook/preview.tsx",
		],
		extends: [
			react.configs["recommended-type-checked"],
			react.configs["disable-naming-convention"],
			hooks.configs.flat.recommended,
			query.configs["flat/recommended"],
		],
		languageOptions: { globals: globals.browser },
		plugins: { "import-x": importX, unicorn },
		rules: {
			// The official hooks plugin owns Compiler and hook diagnostics.
			"@eslint-react/error-boundaries": "off",
			"@eslint-react/exhaustive-deps": "off",
			"@eslint-react/purity": "off",
			"@eslint-react/rules-of-hooks": "off",
			"@eslint-react/set-state-in-effect": "off",
			"@eslint-react/set-state-in-render": "off",
			"@eslint-react/static-components": "off",
			"@eslint-react/unsupported-syntax": "off",
			"@eslint-react/use-memo": "off",
			// useContext remains supported; a lint rollout does not require an API migration.
			"@eslint-react/no-use-context": "off",
			"import-x/no-default-export": "error",
			"import-x/exports-last": "error",
			// Biome owns formatting, import sorting and magic numbers during coexistence.
			"unicorn/no-array-fill-with-reference-type": "error",
			"unicorn/no-await-in-promise-methods": "error",
			"unicorn/no-single-promise-in-promise-methods": "error",
			"unicorn/prefer-array-some": "error",
			"unicorn/prefer-includes": "error",
		},
	},
	{
		files: ["src/**/*.tsx", "packages/*/src/**/*.tsx"],
		ignores: ["**/*.test.tsx", "**/*.stories.tsx", "src/test/**"],
		extends: [refresh.configs.vite],
	},
	{
		files: ["**/*.test.{ts,tsx}"],
		extends: [vitest.configs.recommended],
		rules: {
			"vitest/no-focused-tests": "error",
			"vitest/valid-expect": ["error", { maxArgs: 2 }],
			// it.each cases select different expected outcomes and recovery setup steps.
			"vitest/no-conditional-expect": "off",
			// Async test doubles preserve the public Promise contract without artificial awaits.
			"@typescript-eslint/require-await": "off",
		},
	},
	{
		files: ["**/*.test.tsx"],
		plugins: { "testing-library": testingLibrary },
		// Start with async correctness. DOM structure/geometry tests need direct node access.
		rules: {
			"testing-library/await-async-events": "error",
			"testing-library/await-async-queries": "error",
			"testing-library/await-async-utils": "error",
			"testing-library/no-await-sync-events": "error",
			"testing-library/no-await-sync-queries": "error",
			"testing-library/no-promise-in-fire-event": "error",
			"testing-library/no-wait-for-side-effects": "error",
			"testing-library/no-wait-for-snapshot": "error",
			"testing-library/prefer-find-by": "error",
		},
	},
	storybook.configs["flat/recommended"],
	{
		files: ["**/*.stories.tsx", ".storybook/preview.tsx"],
		rules: {
			"import-x/no-default-export": "off",
			"import-x/exports-last": "off",
		},
	},
);