@inctasoft/simple-log-ts

SonarCloud results

simple-log-ts

npm install @inctasoft/simple-log-ts

• debug, info, warn, error and crit methods.
• JSON format, useful for log ingesting services
• Error, Map Set objects are trnsformed into JSON and also printed
• In case of circular references, output is still JSON, and the message property will contain a string with the value of util.inspect(data, ...inspectOptions). inspectOptions by default is {} but can be overwritten in Log's constructor
• Optional correlation_id can be passed to constructor. Useful for correlating logs from different services. Pass printCorrelation: false in Log's constructor to skip it.

Usage

• Empty config

import { Log } from "@inctasoft/simple-log-ts";

const log = new Log();
log.error("something hapened", new Error('some err msg'));

results in:

{"timestamp":"2023-10-11T21:50:47.405Z","level":"ERROR","message":"something hapened","correlation":"undefined","[Error]":{"stack":"Error: some err msg\n    at Object..(the err stack)","message":"some err msg"}}```

• Log complex objects, provide correlation_id

import { Log } from "@inctasoft/simple-log-ts";
process.env.LOGLEVEL = 'DEBUG' // default level is WARN, un-silence debug method
const log = new Log({ correlation_id: 'some_guid' });
log.debug({
    a: 1, b: 'xyz', my_set: new Set(['foo', 'bar']), nested: {
        my_arr: [
            'elem1',
            new Map([['mapKey', {
                prop1: 1,
                prop2: new Date()
            }]])]
    }
});

results in:

{"timestamp":"2023-10-12T00:14:44.139Z","level":"DEBUG","message":{"a":1,"b":"xyz","my_set":["foo","bar"],"nested":{"my_arr":["elem1",{"mapKey":{"prop1":1,"prop2":"2023-10-12T00:14:44.139Z"}}]}},"correlation":"some_guid"}

• If you are interested in which transformed objects were of Map or Set types, provide printMapSetTypes: true
• Error objects are always printed as {"[Error]": {stack:"...", message: "..."}}
• If you are not into using correlation_id, provide printCorrelation: false

import { Log } from "@inctasoft/simple-log-ts";

const log = new Log({ printMapSetTypes: true, printCorrelation: false});
log.error({
    a: 1, b: 'xyz', my_set: new Set(['foo', 'bar']), nested: {
        my_arr: [
            'elem1',
            new Map([['mapKey', {
                prop1: 1,
                prop2: new Date()
            }]])]
    }
}, new Error("oops something unexpected happened"));

results in:

{"timestamp":"2023-10-12T01:57:31.983Z","level":"ERROR","message":{"a":1,"b":"xyz","my_set":{"[Set]":["foo","bar"]},"nested":{"my_arr":["elem1",{"[Map]":{"mapKey":{"prop1":1,"prop2":"2023-10-12T01:57:31.983Z"}}}]}},"[Error]":{"stack":"Error: oops something unexpected happened\n    at Object..(the err stack)","message":"oops something unexpected happened"}}

• Circular reference handlig

import { Log } from "../src/log";

const obj: any = {};
obj.a = [obj];
obj.b = {};
obj.b.inner = obj.b;
obj.b.obj = obj;

new Log().warn(obj)

results in:

{"timestamp":"2023-10-14T05:59:48.714Z","level":"WARN","message":"<ref *1> {\n  a: [ [Circular *1] ],\n  b: <ref *2> { inner: [Circular *2], obj: [Circular *1] }\n}","correlation":"undefined"}

Log levels

process.env.LOGLEVEL	active methods	notes
DEBUG	debug,info,warn,error,crit
INFO	info,warn,error,crit
WARN	warn,error,crit	default, if no LOGLEVEL is present
ERROR	error,crit	Both crit and error use console.error and accept optional second Error argument
SILENT (or any other value)	crit	Lets you silence all logs, if not using crit method(as it is always active, no matter of LOGLEVEL value)