Check that a sync service has synced all files correctly

sync-report.js

// check that a cloud sync service has synced all files correctly

// on macOS, run this command on both the source and destination machines:
// find . -type f -print0 | xargs -0 stat -f "%N %z" > FILE_NAME
// then run this script with node.

// helpful command to list all file paths that have non-ascii characters:
// LC_COLLATE=C find . -regex '.*[^ -~].*'

import fs from 'fs'

// OPTIONS

const SOURCE_FILE_NAME = 'source.txt'
const DESTINATION_FILE_NAME = 'destination.txt'
const REPORT_FILE_NAME = 'report.txt'

const FILE_NAMES_TO_IGNORE = ['.DS_Store']
const PATHS_TO_IGNORE = [
  SOURCE_FILE_NAME,
  DESTINATION_FILE_NAME,
  REPORT_FILE_NAME,
].map(s => `./${s}`)

// POPULATE ARRAYS

const missingPaths = []
const mismatchedPaths = []
const extraPaths = []

const sourceMap = readFileIntoMap(SOURCE_FILE_NAME)
const destinationMap = readFileIntoMap(DESTINATION_FILE_NAME)
const pathsSet = getValidPathSet([...sourceMap.keys(), ...destinationMap.keys()])

for (const path of pathsSet) {
  if (!destinationMap.has(path)) {
    missingPaths.push(path)
  } else if (!sourceMap.has(path)) {
    extraPaths.push(path)
  } else if (sourceMap.get(path) !== destinationMap.get(path)) {
    mismatchedPaths.push(path)
  }
}

// GENERATE REPORT

let reportString = ``
if (missingPaths.length > 0) {
  reportString += `Paths in source, missing in destination:\n${missingPaths.join('\n')}\n\n`
}
if (mismatchedPaths.length > 0) {
  reportString += `Paths in source, wrong size in destination:\n${mismatchedPaths.join('\n')}\n\n`
}
if (extraPaths.length > 0) {
  reportString += `Paths in destination, not present in source:\n${extraPaths.join('\n')}\n\n`
}

// SAVE REPORT TO FILE

if (!reportString) {
  console.log('Files are in sync! Nothing to report.')
  process.exit()
}

if (fs.existsSync(REPORT_FILE_NAME)) {
  const existingReport = fs.readFileSync(REPORT_FILE_NAME, 'utf-8')
  if (existingReport === reportString) {
    console.log(`Check report in ${REPORT_FILE_NAME}`)
  } else {
    console.error(`${REPORT_FILE_NAME} exists already! Delete/rename and run again.`)
  }
} else {
  fs.writeFileSync(REPORT_FILE_NAME, reportString)
  console.log(`Saved report to ${REPORT_FILE_NAME}`)
}
console.log(`Missing paths: ${missingPaths.length}`, `Mismatched paths: ${mismatchedPaths.length}`, `Extra paths: ${extraPaths.length}`)

// HELPERS

function readFileIntoMap(fileName) {
  const lines = fs.readFileSync(fileName, 'utf-8').split('\n')
  const map = new Map()
  for (let line of lines) {
    const spaceIndex = line.lastIndexOf(' ')
    const path = line.slice(0, spaceIndex)
    const bytesize = line.slice(spaceIndex + 1)
    map.set(path, bytesize)
  }
  return map
}

function getValidPathSet(...paths) {
  const set = new Set(...paths)
  for (const path of set) {
    for (const excludedFileName of FILE_NAMES_TO_IGNORE) {
      if (path.endsWith(excludedFileName)) {
        set.delete(path)
      }
    }
    for (const excludedPath of PATHS_TO_IGNORE) {
      if (path === excludedPath) {
        set.delete(path)
      }
    }
  }
  return set
}