Houston

An advanced Deno logger, with no dependencies.

Usage

You can create really simple or very advanced and complicated, informative logs with Houston.

Importing the module

//you can import all required types, etc. from the mod.ts
import { Houston } from 'https://x.nest.land/Houston@<VERSION>/mod.ts'

Creating a basic logger

For this you will also need to import the ConsoleTransport transport from mod.ts

const Logger = new Houston([
  new ConsoleTransport()
])

Here, we are basically creating a new logger for our project and initializing a new transport, a ConsoleTransport. You can read more about transports here.

If you want to log something, you can easily do it depending on the level of your log:

//logging an info
Logger.log(LogLevel.Info, 'This is an info')
//logging a successful action
Logger.log(LogLevel.Success, 'This is a success notice')
//logging a warning
Logger.log(LogLevel.Warning, 'This is a warning')
//logging an error
Logger.log(LogLevel.Error, 'This is an error')

or if you want to use a shorter form:

Logger.info('Info')
Logger.success('Success')
Logger.warning('Warning')
Logger.error('Error')

API

As explained above, we can use the Houston instance to create a new logger. You can read about it’s configuration below.

Transports

Transports are different methods of logging. You can add them to your logger by including one when initializing

Using FileTransport

When you’re using a FileTransport, an additional param is required to operate, the logFolder param.

You can use it like this:

const Logger = new Houston([
  new ConsoleTransport(),
  new FileTransport('/home/marton/Downloads/logs')
])

This will save log files to the desired folder. The file extension depends on the log format (json or text).
Make sure to add the --allow-write and --allow-read flags when running your code, so Houston can access the log files.

Config

The config is a set of custom options that modify the way your logs look. You can also use them with the transports, when adding one to the Houston instance

All the required types can be imported from mod.ts

A full config object with all properties looks like this:

{
    format: Format.text,
    prefix: new TimePrefix(),
    logLevelDisplay: LogLevelDisplay.Text,
    logColors: {
        [LogLevel.Info]: Color.White,
        [LogLevel.Success]: Color.Green,
        [LogLevel.Warning]: Color.Yellow,
        [LogLevel.Error]: Color.Red
    }
}

format: Format

The format of the logs. Can be text or json

format: Format.json

prefix: Prefix

The prefix of your logs. Can be TimePrefix (prints the time), TextPrefix (a custom prefix by you) or NoPrefix (no prefix before logs)

You can also create your own Prefix implementation by importing Prefix from mod.ts and extending it.

Modifying the TimePrefix date format

You can set the used time format for the TimePrefix to TimeFormat.American or TimeFormat.European

prefix: new TimePrefix(TimeFormat.American)

The TextPrefix prefix

You can apply a custom text like this:

prefix: new TextPrefix('Your prefix')

logLevelDisplay: LogLevelDisplay

You can customize what to display before the log message. This can be LogLevelDisplay.Text (prints the level of the log), LogLevelDisplay.Icon (prints an icon) or LogLevelDisplay.Hidden (no log level displaying).

LogLevelDisplay.Icon

logColors: Record<LogLevel, Color>

The colors of the different log levels. All fields are required, if you want to change one

logColors: {
    [LogLevel.Info]: Color.White,
    [LogLevel.Success]: Color.Green,
    [LogLevel.Warning]: Color.Yellow,
    [LogLevel.Error]: Color.Red
}

Passing config to transports

const Logger = new Houston([
  new ConsoleTransport(
    //adding log levels
    [LogLevel.Info, LogLevel.Success, LogLevel.Warning, LogLevel.Error],
    //passing a config
    { logLevelDisplay: LogLevelDisplay.Icon }
  )
])

If you don’t pass a config to the transport, it will use the default config, determinated by the Houston instance

Screenshots

LogLevelDisplay.Icon

LogLevelDisplay.Text

Custom colors

new TextPrefix('Custom prefix')

Format.json