@hidori/logger

Simple and flexible logger

INSTALL

npm i --save @hidori/logger

USAGE

TEXT OUTPUT

CODE:

import * as Logger from "@hidori/logger";

const logger = new Logger.Logger();

logger.debugSync("hello");
logger.infoSync("hello");
logger.warnSync("hello");
logger.errorSync("hello");
logger.fatalSync("hello");

(async () => {
  await logger.debug("hello");
  await logger.info("hello");
  await logger.warn("hello");
  await logger.error("hello");
  await logger.fatal("hello");
})();

OUTPUT:

2024-02-18T23:15:57.767+09:00 [DEBUG] hello
2024-02-18T23:15:57.774+09:00 [INFO] hello
2024-02-18T23:15:57.775+09:00 [WARN] hello
2024-02-18T23:15:57.775+09:00 [ERROR] hello
2024-02-18T23:15:57.775+09:00 [FATAL] hello
2024-02-18T23:15:57.775+09:00 [DEBUG] hello
2024-02-18T23:15:57.775+09:00 [INFO] hello
2024-02-18T23:15:57.775+09:00 [WARN] hello
2024-02-18T23:15:57.776+09:00 [ERROR] hello
2024-02-18T23:15:57.776+09:00 [FATAL] hello

JSON OUTPUT

CODE:

import * as Logger from "@hidori/logger";

const logger = new Logger.Logger({
  formatter: new Logger.JSONFormatter(),
});

logger.debugSync("hello");
logger.infoSync("hello");
logger.warnSync("hello");
logger.errorSync("hello");
logger.fatalSync("hello");

(async () => {
  await logger.debug("hello");
  await logger.info("hello");
  await logger.warn("hello");
  await logger.error("hello");
  await logger.fatal("hello");
})();

OUTPUT:

{"timestamp":"2024-02-18T23:15:57.722+09:00","level":"debug","data":"hello"}
{"timestamp":"2024-02-18T23:15:57.727+09:00","level":"info","data":"hello"}
{"timestamp":"2024-02-18T23:15:57.727+09:00","level":"warn","data":"hello"}
{"timestamp":"2024-02-18T23:15:57.727+09:00","level":"error","data":"hello"}
{"timestamp":"2024-02-18T23:15:57.727+09:00","level":"fatal","data":"hello"}
{"timestamp":"2024-02-18T23:15:57.728+09:00","level":"debug","data":"hello"}
{"timestamp":"2024-02-18T23:15:57.728+09:00","level":"info","data":"hello"}
{"timestamp":"2024-02-18T23:15:57.728+09:00","level":"warn","data":"hello"}
{"timestamp":"2024-02-18T23:15:57.728+09:00","level":"error","data":"hello"}
{"timestamp":"2024-02-18T23:15:57.728+09:00","level":"fatal","data":"hello"}

API

ASYNC

SIGNATURE:

logger.xxx(data)

xxx is one of the LEVELS

SYNC

SIGNATURE:

logger.xxxSync(data)

xxx is one of the LEVELS

LEVELS

• debug
• info
• warn
• error
• fatal

CONFIGURATION

LEVEL

CODE:

import * as Logger from "@hidori/logger";

const logger = new Logger.Logger({
  level: Logger.levelError,
});

logger.debugSync("hello");
logger.infoSync("hello");
logger.warnSync("hello");
logger.errorSync("hello");
logger.fatalSync("hello");

(async () => {
  await logger.debug("hello");
  await logger.info("hello");
  await logger.warn("hello");
  await logger.error("hello");
  await logger.fatal("hello");
})();

OUTPUT:

2024-02-18T23:52:35.574+09:00 [ERROR] hello
2024-02-18T23:52:35.579+09:00 [FATAL] hello
2024-02-18T23:52:35.579+09:00 [ERROR] hello
2024-02-18T23:52:35.579+09:00 [FATAL] hello

Relationship between level and output:

level	debug()/debugSync()	info()/infoSync()	warn()/warnSync()	error()/errorSync()	fatal()/fatalSync()
levelDebug	O	O	O	O	O
levelInfo	-	O	O	O	O
levelWarn	-	-	O	O	O
levelError	-	-	-	O	O
levelFatal	-	-	-	-	O
levelNone	-	-	-	-	-

FORMATTER

BUILTIN TEXT FORMATTER (DEFAULT)

CODE:

import * as Logger from "../src/index.js";

const logger = new Logger.Logger({
  formatter: new Logger.TextFormatter(),
});

logger.infoSync("hello");

(async () => {
  await logger.info({
    key: "ABC",
    value: "123",
  });
})();

OUTPUT:

2024-02-19T00:20:33.075+09:00 [INFO] hello
2024-02-19T00:20:33.075+09:00 [INFO] hello

BUILTIN JSON FORMATTER

CODE:

import * as Logger from "@hidori/logger";

const logger = new Logger.Logger({
  formatter: new Logger.TextFormatter(),
});

logger.infoSync({
  key: "ABC",
  value: "123",
});

(async () => {
  await logger.info({
    key: "ABC",
    value: "123",
  });
})();

OUTPUT:

{"timestamp":"2024-02-19T00:20:33.037+09:00","level":"info","data":{"key":"ABC","value":"123"}}
{"timestamp":"2024-02-19T00:20:33.037+09:00","level":"info","data":{"key":"ABC","value":"123"}}

CUSTOM FORMATTER

CODE:

const logger = new Logger.Logger({
  formatter: {
    format: (timestamp, level, data) => {
      return `${Logger.toISOStringWithTimezone(timestamp)} [${level.toUpperCase()}] ${JSON.stringify(data)}`;
    }
  },
});

logger.infoSync({
  key: "ABC",
  value: "123",
});

(async () => {
  await logger.info({
    key: "ABC",
    value: "123",
  });
})();

OUTPUT:

2024-02-19T00:34:44.174+09:00 [INFO] {"key":"ABC","value":"123"}
2024-02-19T00:34:44.179+09:00 [INFO] {"key":"ABC","value":"123"}

WRITER

BUILTIN CONSOLE WRITER (DEFAULT)

CODE:

import * as Logger from "@hidori/logger";

const writer = new Logger.ConsoleWriter();
const logger = new Logger.Logger({
  writer: writer,
});

logger.infoSync("hello");

(async () => {
  await logger.info("hello");
})();

OUTPUT:

2024-02-19T00:56:08.305+09:00 [INFO] hello
2024-02-19T00:56:08.309+09:00 [INFO] hello

BUILTIN STRING WRITER

CODE:

import * as Logger from "@hidori/logger";

const writer = new Logger.StringWriter();
const logger = new Logger.Logger({
  writer: writer,
});

logger.infoSync("hello");

(async () => {
  await logger.info("hello");
})();

console.log(writer.toString());

OUTPUT:

2024-02-19T00:56:08.398+09:00 [INFO] hello
2024-02-19T00:56:08.398+09:00 [INFO] hello

CUSTOM WRITER

CODE:

import fs from "fs";
import path from "path";

import * as Logger from "@hidori/logger";

const logger = new Logger.Logger({
  writer: {
    write: async (text) => {
      const fileName = path.join(
        process.env.HOME,
        "./example_config_writer_custom.txt",
      );
      fs.appendFileSync(fileName, text + "\n");
    },

    writeSync: (text) => {
      const fileName = path.join(
        process.env.HOME,
        "./example_config_writer_custom.txt",
      );
      fs.appendFileSync(fileName, text + "\n");
    },
  },
});

logger.infoSync("hello");

(async () => {
  await logger.info("hello");
})();

OUTPUT:

$ cat ~/example_config_writer_custom.txt
2024-02-19T00:48:08.529+09:00 [INFO] hello
2024-02-19T00:48:08.529+09:00 [INFO] hello

LICENSE

MIT

Copyright (c) 2024 Hiroaki SHIBUKI