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

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

const cds = require('../../lib/cds')
const { read, stat } = cds.utils
const crypto = require('crypto')
const { find } = require('../util/fs')

/**
 * Calculate a checksum for a directory, excluding specified patterns.
 * @param {string} dirPath - The directory path to calculate checksum for.
 * @param {(file: string) => boolean} [filter] - the filter function to apply to the found files
 * @param {string} [hashFunction='sha256'] - The hash function to use (default is 'sha256').
 * @returns {Promise<string>} - The checksum as a hex string.
 */
async function calcDirChecksum(dirPath, filter = [], hashFunction = 'sha256', optionalFiles = []) {
  const hash = crypto.createHash(hashFunction)

  let stats
  try {
    stats = await stat(dirPath)
  } catch {
    return hash.digest('hex')
  }

  if (stats.isFile()) {
    hash.update(await read(dirPath, "binary"))
    return hash.digest('hex')
  }

  const files = [...(await find(dirPath, { filter, ignoreSymlinks: true })), ...optionalFiles].sort()
  for (const file of files) {
    try {
      hash.update(file)
      hash.update(await read(file, "binary"))
    } catch {
      // ignore
    }
  }

  return hash.digest('hex')
}

module.exports = { calcDirChecksum }