Hackle

A hackable logger for the 21 Century

Basic Usage

import { makeHackle, tools } from "https://deno.land/x/hackle/mod.ts";

const hackle = makeHackle();
const print = hackle.debug;

hackle.warn("Take a look at hackle", hackle);
print("after `hackle.warn`");
hackle.logStack(); // Logs the call stack to the 'debug' level

hackle.setLoggers([
    tools.makeFileLogger(".log", { prependTime: true }),
    tools.consoleLogger,
]);
hackle.setLogLevel("info");  // Setting this to `null` is akin to entering silent mode

print("will not show");
hackle.notice("on the console and in a log file in the `.log` directory");

To make things easier, you can just import init.ts at the top of the main entry to your application. This just sets the hackle and print variables to the values in the first example.

import "https://deno.land/x/hackle/init.ts";

hackle.error("an error");
print("something to the debug level");

Appearance

By default logs take on the following appearance, but this is completely customizable.

Logs Screenshot

Log Levels

The precedence of the 5 log levels are as follows:

error
warn
notice
info
debug

Scopes

The backbone of Hackle is the principle of scopes. Scopes are added like this…

import 'https://deno.land/x/hackle/init.ts'
import { green } from 'https://deno.land/std/fmt/colors.ts'

hackle.addScope({
    name: 'download',
    prepend: green('Download'),
    level: 'notice'
})

…and accessed like this:

const notifyDownload = hackle.scope('download')

// ... download something ...

notifyDownload('https:something.com')

Console:

Internally, hackle uses a set of default scopes behind the scenes. You can disable this by setting the rejectDefaultScopes option to true, or by calling hackle.removeDefaultScopes.

import { makeHackle } from 'https://deno.land/x/hackle/mod.ts'

const hackle = makeHackle({ rejectDefaultScopes: true })

// or

hackle.removeDefaultScopes()

This way we can easily change the behavior of hackle.error, for example, because internally it just calls the ‘default-error’ scope.

function makeHackle(options: MakeHackleOptions) {
    // ...

    function error(...message: any[]) {
        scope('default-error')(...message)
    }

    // ...

    return {
        // ...
        error,
        // ...
    }
}

To do this, we just need to create a new ‘default-error’ scope. If the scope already exists, it will be overwritten.

hackle.addScope({
    name: 'default-error',
    messageMap(message) {
        return red(tools.defaultStringify(message))
    },
    level: 'error',
})

hackle.error('all red')

Console:

All Red Error

Development

All contributions are heartily welcome!

Hackle uses dirt to help with project configuration.

git clone https://github.com/Vehmloewff/hackle
cd hackle
dirt

License

MIT