@sap/cds-dk/lib/util/glob.js

Command line client and development toolkit for the SAP Cloud Application Programming Model

const path = require('node:path');
const { join } = path;
const { existsSync } = require('node:fs');
const { readdir } = require('node:fs').promises;

/**
 * Returns an AsyncIterator of those (recursive) subdirectories that match the glob pattern.
 * @param pattern - The glob pattern to match against.
 * @param cwd - The current working directory to start the search from.
 * @returns {AsyncIterator<string>} - An array of relative paths that match the glob pattern.
 */
async function* glob(pattern, { cwd } = { cwd: process.cwd() }) {
  if (/\{.*}/.test(pattern)) {
    // We rely on the native Node.js glob support for brace expansion.
    const { glob: globNative } = require('node:fs/promises');
    if (!globNative) {
      throw `Glob pattern '${pattern} requires native Node.js glob support to resolve, which is available in Node.js version 22, but project uses ${process.version}.`
    }
    return globNative(pattern, { cwd });
  }
  yield* (await globArray(pattern, { cwd }));
}

/**
 * Returns those subdirectories, recursively, that match the glob pattern.
 * @param pattern - The glob pattern to match against.
 * @param cwd - The current working directory to start the search from.
 * @returns {Promise<string[]>} - An array of relative paths that match the glob pattern.
 */
async function globArray(pattern, { cwd }) {
  const regex = globToRegex(pattern);
  return (await subdirs(cwd))
      .map(fullPath => path.relative(cwd, fullPath))
      .filter(relativePath => regex.test(relativePath));
}

/**
 * Recursively returns all subdirectories of a given directory.
 * Returns only non-hidden directories (those not starting with a dot).
 * @param {import('fs').PathLike} dir - The directory to search in.
 * @returns {Promise<String[]>} - An array of paths to subdirectories.
 */
async function subdirs(dir) {
  if (!existsSync(dir)) return [];
  const children = (await readdir(dir, { withFileTypes: true }))
      .filter(child => child.isDirectory() && !child.name.startsWith('.'));
  return (await Promise.all(
      children.map(async child => {
        const childPath = join(dir, child.name);
        const descendants = await subdirs(childPath);
        return [childPath, ...descendants];
      })
  )).flat();
}

/**
 * Converts a glob pattern to a regular expression.
 * Supports the following wildcards: `? * ** [...] [!...]`.
 * Patterns such as `./foo` are normalized to `foo`.
 * @param {string} glob - The glob pattern to convert.
 * @returns {RegExp} - The regular expression that matches the glob pattern.
 */
function globToRegex(glob) {
  const regex = glob
      .replace(/^\.\//, '')
      .replaceAll('**', '|')
      .replaceAll(/\[!([^\]]+)]/g, '[^$1]')
      .replaceAll('?', '[^/]')
      .replaceAll('*', '[^/]*')
      .replaceAll('|', '.*');

  return new RegExp(`^${regex}$`);
}

module.exports = {
  glob
};