[Feature Request]: Also allow setting transport level of type (level) => boolean

[movahhedi]

🔎 Search Terms

transport, level

The vision

When passing transports to createLogger(), each transport asks for a level of type string, to use to log higher levels of that. e.g. setting it to warn tells it to log warn, error, fatal.
But there is a need to log a specific level or levels, not lower nor higher. I propose adding support for the type (level) => boolean, to tell whether or not the transport should be called.

Winston.createLogger({
	levels: {
		fatal: 0,
		error: 1,
		warn: 2,
		info: 3,
	},
	transports: [
		new Winston.transports.Console({
			// As usual
			level: "warn",
		}),
		new Winston.transports.File({
			level: (level) => ["fatal", "error"].includes(level),
			filename: Path.join(logDir, "important.log"),
		}),
		new Winston.transports.File({
			level: (level) => level === "info",
			filename: Path.join(logDir, "infoOnly.log"),
		}),
	],
});

Use case

No response

Additional information

No response