.lintstagedrc.js

const path = require('path');

module.exports = {
  '*': filenames => {
    const commands = [];
    const cwd = process.cwd();
    const files = filenames
      .filter(file => !file.match(/\.(ts)$/i))
      .map(file => path.relative(cwd, file))
      .map(file => `'${file}'`);
    if (files.length === 0) {
      return [];
    }

    commands.push(`prettier --write ${files.join(' ')}`);

    return commands;
  },
  '*.ts': filenames => {
    const commands = [];
    const cwd = process.cwd();
    const files = filenames.map(file => path.relative(cwd, file)).map(file => `'${file}'`);
    if (files.length === 0) {
      return [];
    }

    const filesForLint = filenames
      .map(file => path.relative(cwd, file))
      .filter(file => !file.match(/^e2e\//i))
      .filter(file => !file.match(/^test\//i))
      .map(file => `'${file}'`);

    if (filesForLint.length) {
      commands.push(`npm run lint -- --fix --force`);
    }
    commands.push(`prettier --write ${files.join(' ')}`);

    return commands;
  },
};