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Javascript Logger
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{ | |
"colorsEnabled": true, | |
"defaultConf": { | |
"info": { | |
"enabled": false, | |
"color": "Blue" | |
}, | |
"warning": { | |
"enabled": true, | |
"color": "Yellow" | |
}, | |
"error": { | |
"enabled": true, | |
"color": "Red" | |
} | |
}, | |
"packagepath": "../package.json" | |
} |
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// Define color codes for terminal emulators | |
const Colors = { | |
Reset: "\x1b[0m", | |
Bright: "\x1b[1m", | |
Dim: "\x1b[2m", | |
Underscore: "\x1b[4m", | |
Blink: "\x1b[5m", | |
Reverse: "\x1b[7m", | |
Hidden: "\x1b[8m", | |
FgBlack: "\x1b[30m", | |
FgRed: "\x1b[31m", | |
FgGreen: "\x1b[32m", | |
FgYellow: "\x1b[33m", | |
FgBlue: "\x1b[34m", | |
FgMagenta: "\x1b[35m", | |
FgCyan: "\x1b[36m", | |
FgWhite: "\x1b[37m", | |
BgBlack: "\x1b[40m", | |
BgRed: "\x1b[41m", | |
BgGreen: "\x1b[42m", | |
BgYellow: "\x1b[43m", | |
BgBlue: "\x1b[44m", | |
BgMagenta: "\x1b[45m", | |
BgCyan: "\x1b[46m", | |
BgWhite: "\x1b[47m" | |
} | |
function generateConfig(loggerConfig) { | |
let {packagepath, defaultConf} = loggerConfig; | |
let {name, version} = require(packagepath); | |
return { | |
logLevels: require('process').argv.slice(2).reduce( | |
(config, arg) => { | |
if (arg.startsWith('-l')) { | |
config[arg.slice(2)].enabled = true; | |
} | |
else if (arg.startsWith('-lr')) { | |
config[arg.slice(3)].enabled = false; | |
} | |
return config; | |
}, | |
defaultConf | |
), | |
name: name, | |
version: version, | |
} | |
} | |
module.exports = class Logger { | |
constructor(config) { | |
// Don't print color codes when colors are not enabled | |
this.colors = new Proxy(Colors, { | |
get: function(obj, prop) { | |
return config.colorsEnabled ? obj[prop] : ""; | |
} | |
}) | |
this.config = generateConfig(config); | |
this.generateLogFunctions(); | |
this.printHead(); | |
} | |
generateLogFunctions() { | |
Object.keys(this.config.logLevels).forEach( name => this[name] = this.logFunction(name)); | |
} | |
logFunction(name, enabled) { | |
return message => this.config.logLevels[name].enabled && | |
console.log(`[${this.colors['Fg' + this.config.logLevels[name].color] + name + this.colors.Reset}] message`); | |
} | |
printHead() { | |
// Prints head text like so: | |
// npm-package-name v7.6.0 | |
console.log(`${this.colors.BgBlue + this.colors.FgWhite + this.config.name + this.colors.Reset} v${this.config.version}`) | |
} | |
} | |
let l = new Logger(require("./log.json")); | |
l.info('test') | |
l.warning('test2') | |
l.error('test3') |
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