Selective formatting of Pino output while preserving third-party output

[hanszoons]

I frequently use pino-pretty alongside other tools (e.g., test runners). When I pipe the output to npx pino-pretty, the formatting of everything not generated by pino gets erased. Is there a way to instruct pino-pretty to only format the output originating from pino (ndjson), while keeping the output from third-party tools that interweaves completely intact?

[jsumners]

That's what the tool is designed to do:

pino-pretty/lib/pretty.js

Lines 40 to 47 in 41fdd31

	if (!isObject(inputData)) {
	const parsed = jsonParser(inputData)
	if (parsed.err || !isObject(parsed.value)) {
	// pass through
	return inputData + this.EOL
	}
	log = parsed.value
	} else {

[hanszoons]

But yet all formatting is removed on whatever is passed through?

left: npx vitest, right: npx vitest | npx pino-pretty

[jsumners]

If it isn't piping to stdin then there is nothing we can do about it.

[hanszoons]

I'm afraid I don't understand, is there anything I can do about it myself?

[jsumners]

I do not know what npx vitest does to write its output to the terminal. But some-app | pino-pretty will do as desired if some-app is writing its output to stdout such that it pipes to the stdin of pino-pretty.