utils.ts

import { writeFileSync } from 'fs';
import { resolve } from 'path';

import type { TSESLint } from '@typescript-eslint/experimental-utils';
import { format, resolveConfig } from 'prettier';

const prettierConfig = resolveConfig.sync(__dirname);

export type LinterConfig = TSESLint.Linter.Config;

const addAutoGeneratedComment = (code: string) =>
  [
    '// THIS CODE WAS AUTOMATICALLY GENERATED',
    '// DO NOT EDIT THIS CODE BY HAND',
    '// YOU CAN REGENERATE IT USING npm run generate:configs',
    '',
    code,
  ].join('\n');

/**
 * Helper function writes configuration.
 */
export const writeConfig = (config: LinterConfig, configName: string): void => {
  // note: we use `export =` because ESLint will import these configs via a commonjs import
  const code = `export = ${JSON.stringify(config)};`;
  const configStr = format(addAutoGeneratedComment(code), {
    parser: 'typescript',
    ...prettierConfig,
  });
  const filePath = resolve(__dirname, `../../lib/configs/${configName}.ts`);

  writeFileSync(filePath, configStr);
};