Buffer From String

Easy
5 views 25 Jan 2026
Create a Buffer from a string and print its byte length....

Hex To Buffer

Medium
4 views 25 Jan 2026
Read a hex string and print the utf8 text....

Stream Copy File

Hard
3 views 25 Jan 2026
Copy a file using streams and print DONE....

Readable Stream Line Counter

Hard
3 views 25 Jan 2026
Count how many lines are in stdin using streams....

Transform Uppercase Stream

Medium
3 views 25 Jan 2026
Read stdin, convert to uppercase, write to stdout....

Backpressure Idea Demo

Hard
4 views 25 Jan 2026
Pipe a readable to writable and log when drain happens....

JSON Lines Writer

Medium
5 views 25 Jan 2026
Write an array as JSONL (one JSON per line)....

Gzip Compress Text

Hard
4 views 25 Jan 2026
Compress a string with gzip and print compressed byte length....

Decode Base64

Easy
4 views 25 Jan 2026
Read base64 from stdin and print decoded text....

Chunked JSON Parse Problem

Hard
3 views 25 Jan 2026
Explain why JSON.parse on stream chunks fails, and fix by buffering....

SHA256 Of Stdin Stream

Hard
5 views 25 Jan 2026
Read stdin as stream and print sha256 hex....

pipeline Promise

Hard
6 views 25 Jan 2026
Use stream.pipeline with a promise wrapper to copy file....

ObjectMode Filter Stream

Hard
3 views 25 Jan 2026
Filter objects in a stream (only keep level=hard) and output JSONL....

Buffer.concat Example

Easy
6 views 25 Jan 2026
Join multiple buffers and print final text....

Slice Buffer Range

Medium
5 views 25 Jan 2026
Read text, slice first 4 bytes, and print it....

PassThrough Logger

Medium
4 views 25 Jan 2026
Use PassThrough to tap into a stream and count bytes....

Line Split Transform

Hard
4 views 25 Jan 2026
Split stdin by lines using a Transform and print number of lines....

Readable From Generator

Medium
3 views 25 Jan 2026
Create a readable stream from a generator and print output....

Count Bytes In File Stream

Hard
4 views 25 Jan 2026
Count bytes in a file using createReadStream....

Download With Stream

Hard
3 views 25 Jan 2026
Download a URL to a file using streams and print DONE....