[BUG] Piping non-ASCII output breaks console.log

[matheusb-comp]

Detected this situation while running a code that prints a QR code to the terminal using qrcode-terminal.
It was using the small option, and checking the code, the lib seems to just print some unicode characters.

Example script:

const num = 15;
const char = '🐞';
[...Array(num)].forEach(() => console.log(char));
setInterval(() => console.log('A'), 1000);

When running this script piping the output (node index.js | pino-pretty), the higher num is, the longer it takes for the A logs to appear in the terminal, and when it happens, many of them are shown at once, instead of every second.

Running the code without piping to pino-pretty, or changing char to ASCII, like a dot (.), makes everything run normal again.

Environment

SO: Ubuntu 21.10 impish
Node: v17.2.0
pino-pretty: 7.6.0

[mcollina]

Would you like to send a Pull Request to address this issue? Remember to add unit tests.

[matheusb-comp]

Sorry, but I don't believe I have enough knowledge about stream transformation to send a PR to fix this.
I tried looking at the code and got confused about how it actually works.

As a workaround, I'm now using pino-pretty via programmatic integration, but using an environment variable to add the transport.target only in development.

[jsumners]

This looks like a stream is buffering, but the defaults I see for the pino-pretty cli do not create a buffered stream?