๐Ÿ‘‹ Hackable console logger
Switch branches/tags
Clone or download

readme.md

Signale

๐Ÿ‘‹ Hackable console logger

Header

Build Status NPM Downloads

Description

Hackable and configurable to the core, signale can be used for logging purposes, status reporting, as well as for handling the output rendering process of other node modules and applications.

Read this document in: ็ฎ€ไฝ“ไธญๆ–‡.

Visit the contributing guidelines to learn more on how to translate this document into more languages.

Come over to Gitter or Twitter to share your thoughts on the project.

Highlights

  • 16 out-of-the-box loggers
  • Hackable to the core
  • Clean and beautiful output
  • Integrated timers
  • Custom pluggable loggers
  • Interactive and regular modes
  • Filename, date and timestamp support
  • Scoped loggers and timers
  • String interpolation support
  • Multiple configurable writable streams
  • Simple and minimal syntax
  • Globally configurable through package.json
  • Overridable configuration per file and logger

Contents

Install

npm install signale

Usage

Default Loggers

Import signale and start using any of the default loggers.

View all of the available loggers.
  • await
  • complete
  • error
  • debug
  • fatal
  • fav
  • info
  • note
  • pause
  • pending
  • star
  • start
  • success
  • warn
  • watch
  • log

const signale = require('signale');

signale.success('Operation successful');
signale.debug('Hello', 'from', 'L59');
signale.pending('Write release notes for %s', '1.2.0');
signale.fatal(new Error('Unable to acquire lock'));
signale.watch('Recursively watching build directory...');
signale.complete({prefix: '[task]', message: 'Fix issue #59', suffix: '(@klauscfhq)'});
Default Loggers

Custom Loggers

To create a custom logger define an options object yielding a types field with the logger data and pass it as argument to a new signale instance.

const {Signale} = require('signale');

const options = {
  disabled: false,
  interactive: false,
  stream: process.stdout,
  scope: 'custom',
  types: {
    remind: {
      badge: '**',
      color: 'yellow',
      label: 'reminder'
    },
    santa: {
      badge: '๐ŸŽ…',
      color: 'red',
      label: 'santa'
    }
  }
};

const custom = new Signale(options);
custom.remind('Improve documentation.');
custom.santa('Hoho! You have an unused variable on L45.');
Custom Loggers

Here is an example where we override the default error and success loggers.

const {Signale} = require('signale');

const options = {
  types: {
    error: {
      badge: '!!',
      label: 'fatal error'
    },
    success: {
      badge: '++',
      label: 'huge success'
    }
  }
};

const signale = new Signale();
signale.error('Default Error Log');
signale.success('Default Success Log');

const custom = new Signale(options);
custom.error('Custom Error Log');
custom.success('Custom Success Log');
Default Loggers

The options object can hold any of the following attributes: disabled, interactive, stream, scope and types.

disabled
  • Type: Boolean
  • Default: false

Disables the logging functionality of all loggers belonging to the created instance.

interactive
  • Type: Boolean
  • Default: false

Switches all loggers belonging to the created instance into the interactive mode.

stream
  • Type: Writable stream or Array of Writable streams
  • Default: process.stdout

Destination to which the data is written, can be a single valid Writable stream or an array holding multiple valid Writable streams.

scope
  • Type: String or Array of Strings

Name of the scope the logger is reporting from.

types
  • Type: Object

Holds the configuration of the custom and default loggers.

badge
  • Type: String

The icon corresponding to the logger.

label
  • Type: String

The label used to identify the type of the logger.

color
  • Type: String

The color of the label, can be any of the foreground colors supported by chalk.

Scoped Loggers

To create a scoped logger from scratch, define the scope field inside the options object and pass it as argument to a new signale instance.

const {Signale} = require('signale');

const options = {
  scope: 'global scope'
};

const global = new Signale(options);
global.success('Successful Operation');
Scope Vanilla

To create a scoped logger based on an already existing one, use the scope() function, which will return a new signale instance, inheriting all custom loggers, timers, streams, configuration, interactive mode & disabled statuses from the initial one.

const signale = require('signale');

const global = signale.scope('global scope');
global.success('Hello from the global scope');

function foo() {
  const outer = global.scope('outer', 'scope');
  outer.success('Hello from the outer scope');
  
  setTimeout(() => {
    const inner = outer.scope('inner', 'scope'); 
    inner.success('Hello from the inner scope');
  }, 500);
}

foo();
Scope Existing

Interactive Loggers

To initialize an interactive logger, create a new signale instance with the interactive attribute set to true. While into the interactive mode, previously logged messages originating from an interactive logger, will be overridden only by new ones originating from the same or a different interactive logger. Note that regular messages originating from regular loggers are not overridden by the interactive ones.

const {Signale} = require('signale');

const interactive = new Signale({interactive: true, scope: 'interactive'});

interactive.await('[%d/4] - Process A', 1);

setTimeout(() => {
  interactive.success('[%d/4] - Process A', 2);
  setTimeout(() => {
    interactive.await('[%d/4] - Process B', 3);
    setTimeout(() => {
      interactive.error('[%d/4] - Process B', 4);
      setTimeout(() => {}, 1000);
    }, 1000);
  }, 1000);
}, 1000);
Interactive Mode

Writable Streams

By default, all signale instances log their messages to the process.stdout stream. This can be modified, to match your own preference, through the stream property, where you can define a single or multiple valid Writable streams, which will be used by all logger types to log your data. Additionally, it is possible to define one or more Writable streams exclusively for a specific logger type, thus write data independently from the rest logger types.

const {Signale} = require('signale');

const options = {
  stream: process.stderr, // All loggers will now write to `process.stderr`
  types: {
    error: {
      // Only `error` will write to both `process.stdout` & `process.stderr`
      stream: [process.stdout, process.stderr]
    }
  }
};

const signale = new Signale(options);
signale.success('Message will appear on `process.stderr`');
signale.error('Message will appear on both `process.stdout` & `process.stderr`');
Writable Streams

Timers

Timer are managed by the time() and timeEnd() functions. A unique label can be used to identify a timer on initialization, though if none is provided the timer will be assigned one automatically. In addition, calling the timeEnd() function without a specified label will have as effect the termination of the most recently initialized timer, that was created without providing a label.

const signale = require('signale');

signale.time('test');
signale.time();
signale.time();

setTimeout(() => {
  signale.timeEnd();
  signale.timeEnd();
  signale.timeEnd('test');
}, 500);
Timers

Configuration

Global

To enable global configuration define the options under the signale namespace in your package.json.

The following illustrates all the available options with their respective default values.

{
  "signale": {
    "coloredInterpolation": false,
    "displayScope": true,
    "displayBadge": true,
    "displayDate": false,
    "displayFilename": false,
    "displayLabel": true,
    "displayTimestamp": false,
    "underlineLabel": true,
    "underlineMessage": false,
    "underlinePrefix": false,
    "underlineSuffix": false,
    "uppercaseLabel": false
  }
}
View all of the available options in detail.
coloredInterpolation
  • Type: Boolean
  • Default: false

Display the arguments, which replace the placeholder tokens on string interpolation, colored.

displayScope
  • Type: Boolean
  • Default: true

Display the scope name of the logger.

displayBadge
  • Type: Boolean
  • Default: true

Display the badge of the logger.

displayDate
  • Type: Boolean
  • Default: false

Display the current local date in YYYY-MM-DD format.

displayFilename
  • Type: Boolean
  • Default: false

Display the name of the file that the logger is reporting from.

displayLabel
  • Type: Boolean
  • Default: true

Display the label of the logger.

displayTimestamp
  • Type: Boolean
  • Default: false

Display the current local time in HH:MM:SS format.

underlineLabel
  • Type: Boolean
  • Default: true

Underline the logger label.

underlineMessage
  • Type: Boolean
  • Default: false

Underline the logger message.

underlinePrefix
  • Type: Boolean
  • Default: false

Underline the logger prefix.

underlineSuffix
  • Type: Boolean
  • Default: false

Underline the logger suffix.

uppercaseLabel
  • Type: Boolean
  • Default: false

Display the label of the logger in uppercase.

Local

To enable local configuration call the config() function on your signale instance. Local configurations will always override any pre-existing configuration inherited from package.json.

In the following example, loggers in the foo.js file will run under their own configuration, overriding the package.json one.

// foo.js
const signale = require('signale');

// Overrides any existing `package.json` config
signale.config({
  displayFilename: true,
  displayTimestamp: true,
  displayDate: false
}); 

signale.success('Hello from the Global scope');
Local Config

Also, scoped loggers can have their own independent configuration, overriding the one inherited by the parent instance or package.json.

// foo.js
const signale = require('signale');

signale.config({
  displayFilename: true,
  displayTimestamp: true,
  displayDate: false
});

signale.success('Hello from the Global scope');

function foo() {
  // `fooLogger` inherits the config of `signale`
  const fooLogger = signale.scope('foo scope');

  // Overrides both `signale` and `package.json` configs
  fooLogger.config({
    displayFilename: true,
    displayTimestamp: false,
    displayDate: true
  });

  fooLogger.success('Hello from the Local scope');
}

foo();
Scope Config

API

signale.<logger>(message[, message]|messageObj|errorObj)

logger
  • Type: Function

Can be any default or custom logger.

message
  • Type: String

Can be one or more comma delimited strings.

const signale = require('signale');

signale.success('Successful operation');
//=> โœ”  success  Successful operation

signale.success('Successful', 'operation');
//=> โœ”  success  Successful operation

signale.success('Successful %s', 'operation');
//=> โœ”  success  Successful operation
errorObj
  • Type: Error Object

Can be any error object.

const signale = require('signale');

signale.error(new Error('Unsuccessful operation'));
//=> โœ–  error  Error: Unsuccessful operation
//        at Module._compile (module.js:660:30)
//        at Object.Module._extensions..js (module.js:671:10)
//        ...
messageObj
  • Type: Object

Can be an object holding the prefix, message and suffix attributes, with prefix and suffix always prepended and appended respectively to the logged message.

const signale = require('signale');

signale.complete({prefix: '[task]', message: 'Fix issue #59', suffix: '(@klauscfhq)'});
//=> [task] โ˜’  complete  Fix issue #59 (@klauscfhq)

signale.complete({prefix: '[task]', message: ['Fix issue #%d', 59], suffix: '(@klauscfhq)'});
//=> [task] โ˜’  complete  Fix issue #59 (@klauscfhq)

signale.scope(name[, name])

Defines the scope name of the logger.

name
  • Type: String

Can be one or more comma delimited strings.

const signale = require('signale');

const foo = signale.scope('foo'); 
const fooBar = signale.scope('foo', 'bar');

foo.success('foo');
//=> [foo] โ€บ โœ”  success  foo

fooBar.success('foo bar');
//=> [foo] [bar] โ€บ โœ”  success  foo bar

signale.unscope()

Clears the scope name of the logger.

const signale = require('signale');

const foo = signale.scope('foo'); 

foo.success('foo');
//=> [foo] โ€บ โœ”  success  foo

foo.unscope();

foo.success('foo');
//=> โœ”  success  foo

signale.config(settingsObj)

Sets the configuration of an instance overriding any existing global or local configuration.

settingsObj
  • Type: Object

Can hold any of the documented options.

// foo.js
const signale = require('signale');

signale.config({
  displayFilename: true,
  displayTimestamp: true,
  displayDate: true
});

signale.success('Successful operations');
//=> [2018-5-15] [11:12:38] [foo.js] โ€บ โœ”  success  Successful operations

signale.time([, label])

  • Return Type: String

Sets a timers and accepts an optional label. If none provided the timer will receive a unique label automatically.

Returns a string corresponding to the timer label.

label
  • Type: String

Label corresponding to the timer. Each timer must have its own unique label.

const signale = require('signale');

signale.time();
//=> โ–ถ  timer_0  Initialized timer...

signale.time();
//=> โ–ถ  timer_1  Initialized timer...

signale.time('label');
//=> โ–ถ  label    Initialized timer...

signale.timeEnd([, label])

  • Return Type: Object

Deactivates the timer to which the given label corresponds. If no label is provided the most recent timer, that was created without providing a label, will be deactivated.

Returns an object {label, span} holding the timer label and the total running time.

label
  • Type: String

Label corresponding to the timer, each timer has its own unique label.

const signale = require('signale');

signale.time();
//=> โ–ถ  timer_0  Initialized timer...

signale.time();
//=> โ–ถ  timer_1  Initialized timer...

signale.time('label');
//=> โ–ถ  label    Initialized timer...

signale.timeEnd();
//=> โ—ผ  timer_1  Timer run for: 2ms

signale.timeEnd();
//=> โ—ผ  timer_0  Timer run for: 2ms

signale.timeEnd('label');
//=> โ—ผ  label    Timer run for: 2ms

signale.disable()

Disables the logging functionality of all loggers belonging to a specific instance.

const signale = require('signale');

signale.success('foo');
//=> โœ”  success  foo

signale.disable();

signale.success('foo');
//=>

signale.enable()

Enables the logging functionality of all loggers belonging to a specific instance.

const signale = require('signale');

signale.disable();

signale.success('foo');
//=>

signale.enable();

signale.success('foo');
//=> โœ”  success  foo

signale.isEnabled()

Checks whether the logging functionality of a specific instance is enabled.

const signale = require('signale');

signale.success('foo');
//=> โœ”  success  foo

signale.isEnabled();
// => true

signale.disable();

signale.success('foo');
//=>

signale.isEnabled();
// => false

Development

For more info on how to contribute to the project, please read the contributing guidelines.

  • Fork the repository and clone it to your machine
  • Navigate to your local fork: cd signale
  • Install the project dependencies: npm install or yarn install
  • Lint code for errors: npm test or yarn test

Related

  • chalk - Terminal string styling done right
  • figures - Unicode symbols

Who's Using It?

View in detail all the packages and repositories that are using Signale here.

Team

License

MIT