.lintstagedrc.mjs

import { ESLint } from 'eslint';
import { glob } from 'glob';
import { relative } from 'node:path';
import process from 'node:process';

const ignoredFiles = [
    '**/node_modules/**',
    '**/.next/**',
    '**/.vitest/**',
    '**/*.d.ts',
    '**/dist/**',
    '**/storybook-static/**',
    '**/vite.config.ts',
    '**/vitest.config.ts',
    '**/vitest.setup.ts',
    '**/vitest.workspace.ts'
];

const filterIgnoredFiles = async (requestedFiles) => {
    const cwd = process.cwd();
    const eslint = new ESLint({
        // Override ESLint's cwd to resolve to the project root, so that
        // relative paths work as intended. Otherwise, the paths resolve
        // to the directory where lint-staged is run.
        cwd
    });

    const files = requestedFiles.map((file) => relative(cwd, file));
    const eslintIgnores = await Promise.all(files.map((file) => eslint.isPathIgnored(file)));

    const filesToLint = files
        .filter((_, index) => !eslintIgnores[index])
        .filter((file) => {
            // Filter using `ignoredFiles` and `glob`
            return !glob.hasMagic(file, { ignore: ignoredFiles });
        })
        .map((file) => `./${file}`);

    return filesToLint.join(' ');
};

const testAndLintAll = async (_) => {
    const cwd = process.cwd();
    const allFiles = await glob(`${cwd}/**/*.{ts,tsx}`, {
        ignore: ignoredFiles
    });
    const allPrettierFiles = (
        await glob(`${cwd}/**/*.{mjs,ts,tsx,json,scss}`, {
            ignore: ignoredFiles
        })
    )
        .map((file) => relative(cwd, file))
        .map((file) => `./${file}`)
        .join(' ');

    const filesToLint = await filterIgnoredFiles(allFiles);

    const prettier = `prettier --write ${allPrettierFiles}`;
    const eslint = `eslint --max-warnings=0 --fix ${filesToLint}`;

    return [...(filesToLint.length > 0 ? [eslint] : []), ...(allPrettierFiles.length > 0 ? [prettier] : [])];
};

export default {
    '**/*.{js,ts,jsx,tsx}': async (files) => {
        const filesToLint = await filterIgnoredFiles(files);
        if (filesToLint.length === 0) return [];

        return [`prettier --write ${filesToLint}`, `eslint --max-warnings=0 --fix ${filesToLint}`];
    },
    '**/*.{css,scss}': async (files) => {
        const filesToLint = await filterIgnoredFiles(files);
        if (filesToLint.length === 0) return [];

        return [`prettier --write ${filesToLint}`];
    },

    // Lint and test all files since dependency updates could potentially break tests.
    '**/package.json': testAndLintAll
};