Data Processing CLI

[maiano]

1. Task: link
2. Done 2026-03-15 / deadline 2026-03-16
3. Score: 226/296

Basic Scope

• +6 Application starts with npm run start and displays welcome message
• +10 Application exits gracefully with .exit command or Ctrl+C and displays goodbye message
• +6 Current working directory is printed at startup and after each successful operation
• +10 Unknown or invalid commands display Invalid input and application continues running
• +10 Operations that fail display Operation failed and application continues running

Navigation Commands

• +8 up command moves up one directory level correctly
• +8 cd command navigates to specified directory (both relative and absolute paths)
• +12 ls command lists files and folders with proper sorting (folders first, then files, alphabetically)

Data Processing Commands

• +20 csv-to-json command works correctly (headers parsed, rows converted to objects, output is valid JSON array, uses Streams)
• +20 json-to-csv command works correctly (headers from object keys, values as rows, uses Streams)
• +12 count command works correctly (lines, words, characters counted via Streams, output format matches specification)
• +12 hash command works correctly (SHA256 by default, supports md5 and sha512 via --algorithm option, uses Streams, supports --save to write hash file next to input)
• +8 encrypt command works correctly (AES-256-GCM, key derivation from password+salt, Streams, output format matches spec)
• +8 decrypt command works correctly (AES-256-GCM, key derivation from password+salt, Streams, authTag verified, result matches original)

Path Resolution

• +16 All file paths in commands are correctly resolved relative to current working directory
• +10 All file operations properly handle errors (non-existent files, invalid paths, permission errors)

Advanced Scope

• +26 log-stats command works correctly:
  • +6 File is split into chunks equal to the number of CPU cores (line boundaries preserved)
  • +10 Each chunk is processed in a separate Worker Thread
  • +6 Partial stats are merged correctly (counters, maps, totals)
  • +6 Final output JSON matches the specification
• +16 Project structure follows the specification (separate files for navigation, commands, utilities, worker)
• +20 Interactive REPL implementation:
  • +10 Maintains application state (current working directory) across commands
  • +10 Properly handles readline for continuous command input
• +10 hash-compare command works correctly (reads expected hash from file, computes current hash with selected algorithm, returns OK / MISMATCH)