CODEWITHSUNDEEP
node.jsloggingwinston
OKEE
OKEE

Reputation: 460

NodeJS Winston logger not printing trace

Using Winston logger with my NodeJS project I cant find a way to configure logger to output logs in following format:

[ 'timestamp' ] : [ 'level' ] -> 'message' [ if error: trace else nothing ]

My current format looks following:

const logger = winston.createLogger({
  transports: new transports.Console({
    format: format.combine(
      format.errors({ stack: true }),
      format.timestamp({ format: "MMM-DD-YYYY HH:mm:ss" }),
      format.align(),
      format.printf(
        ({ level, message, timestamp, stack }) =>
          `[${timestamp}]  [${level}]:  ${message}  ${level == "error" ? stack : ""}`
      )
    ),
  }),
});

logging for example: logger.error("Some text on error");

results in: [Jan-20-2022 14:20:43] [error]: Some text on error undefined

What is the problem?

Upvotes: 2

Views: 3746

Answers (1)

Maxim Egorushkin
Maxim Egorushkin

Reputation: 136505

Getting stack-trace works only with Error objects which have Error.stack property:

logger.error(new Error("Some text on error"));

See documentation for logform.format.errors:

The errors format allows you to pass in an instance of a JavaScript Error directly to the logger. It allows you to specify whether not to include the stack-trace.

Here is a complete TypeScript/JavaScript example:

#!/bin/env ts-node-esm
import winston from 'winston';

const log = winston.createLogger({
    level: 'info',
    format: winston.format.combine(
        winston.format.errors({stack: true}),
        winston.format.timestamp({format: "YYYY-MM-DD HH:mm:ss.SSS"}),
        winston.format.printf(({timestamp, level, message, stack}) => {
            const text = `${timestamp} ${level.toUpperCase()} ${message}`;
            return stack ? text + '\n' + stack : text;
        }),
    ),
    transports: [
        new winston.transports.Console(),
    ],
});

function fail() {
    throw new Error("Some text on error")
}

try {
    fail();
}
catch(e) {
    console.log("console");
    console.log("abc", e);
    console.log();

    console.log("winston");
    log.error("abc", e);
    console.log();

    log.info("No error");
    log.error("No error");
}

Output:

console
abc Error: Some text on error
    at fail (file:///home/max/src/quant-research/tests/ts-test.ts:20:11)
    at file:///home/max/src/quant-research/tests/ts-test.ts:24:5
    at ModuleJob.run (node:internal/modules/esm/module_job:193:25)
    at async Promise.all (index 0)
    at async ESMLoader.import (node:internal/modules/esm/loader:533:24)
    at async loadESM (node:internal/process/esm_loader:91:5)
    at async handleMainPromise (node:internal/modules/run_main:65:12)

winston
2023-02-22 02:37:00.063 ERROR abc Some text on error
Error: Some text on error
    at fail (file:///home/max/src/quant-research/tests/ts-test.ts:20:11)
    at file:///home/max/src/quant-research/tests/ts-test.ts:24:5
    at ModuleJob.run (node:internal/modules/esm/module_job:193:25)
    at async Promise.all (index 0)
    at async ESMLoader.import (node:internal/modules/esm/loader:533:24)
    at async loadESM (node:internal/process/esm_loader:91:5)
    at async handleMainPromise (node:internal/modules/run_main:65:12)

2023-02-22 02:37:00.063 INFO No error
2023-02-22 02:37:00.064 ERROR No error

Upvotes: 4

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