`log.log("warning", "message")` works, but `log.warning("message") doesn't

Please tell us about your environment:

• winston version?
  • winston@2
  • winston@3
• _node -v outputs: v10.16.0
• _Operating System? macOS & Linux
• _Language? TypeScript 3.3, JavaScript

What is the problem?

A call to log.log("warning", "message") works, but a call to log.warning("message") doesn’t. This is with a Console logger and syslog levels.

Online example of problem: https://repl.it/repls/LongtermCloudyCircles

const winston = require("winston");
winston.loggers.add("default");
const log = winston.loggers.get("default");
log.levels = winston.config.syslog.levels;
log.add(new winston.transports.Console());

log.log("warning", "named warning message");
log.warning("warning message");

Running that code will produce the following:

{"level":"warning","message":"named warning message"}
./scratch.js:8
log.warning("warning message");
    ^

TypeError: log.warning is not a function
    at Object.<anonymous> (/Users/cjbarth/meps/wol-castle/scratch.js:8:5)
    at Module._compile (internal/modules/cjs/loader.js:776:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:829:12)
    at startup (internal/bootstrap/node.js:283:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)

What do you expect to happen instead?

{“level”:“warning”,“message”:“named warning message”} {“level”:“warning”,“message”:“warning message”}

[wbt]

For those looking for a quick fix, try doing a project-wide find (in your own project) for log.warning( and replace it with log.warn(. I agree it would be a good idea to handle .warning more elegantly though.

[jleverenz]

Somewhat new to winston internals, but I believe this is due to how the example is setting levels. If not set during logger configuration, winston will not setup the logger prototype with the per-level convenience functions (log.warning)

However, if passed as configuration, log.warning is available:

const winston = require("winston");
winston.loggers.add("default", {
  levels: winston.config.syslog.levels
});
const log = winston.loggers.get("default");
log.add(new winston.transports.Console());

log.log("warning", "named warning message");
log.warning("warning message");

Thoughts? I’m thinking this is a non-issue, and setting levels via log.levels = is not intended to be supported.