How to use caterpillar - 10 common examples

// Import
var level   = process.argv.indexOf('-d') === -1 ? 6 : 7;
var logger  = require('caterpillar').createLogger({level:level});
var filter  = require('caterpillar-filter').createFilter();
var human   = require('caterpillar-human').createHuman();

// Where to output?
if ( process.title === 'browser' ) {
	// Include the browser compatibility layer
	var browser = require('caterpillar-browser').createBrowser();

	// Pipe to filter to human to browser
	logger.pipe(filter).pipe(human).pipe(browser);
}
else {
	// Pipe to filter to human to stdout
	logger.pipe(filter).pipe(human).pipe(process.stdout);

	// If we are debugging, then write the original logger data to debug.log

const cli = require('commander')

// Import our package data for versioning
const { version } = require('../package.json')

// Import out projectz utility
const { Projectz } = require('./index.js')

// Prepare our logging configuration
const LOG_LEVEL_INFO = 6
const LOG_LEVEL_DEBUG = 7
const EXIT_ERROR_CODE = 1
const level = process.argv.includes('-d') ? LOG_LEVEL_DEBUG : LOG_LEVEL_INFO

// Setup our logging
const logger = new Logger({ level })
const filter = new Filter()
const human = new Human()

// Pipe logger output to filter, then filter output to stdout
logger
	.pipe(filter)
	.pipe(human)
	.pipe(process.stdout)

// Extract out version out of our package and apply it to commander
cli.version(version)

// Define usage information
cli.usage(' [options]')

// Add our cwd customisation

// Import
var logger = require('caterpillar').createLogger();
var filter = require('./').createFilter({level:6});  // omit log level entries above 6

// Pipe logger output to filter, then filter output to stdout
logger.pipe(filter).pipe(process.stdout);

// Log
logger.log('info',  'this is the first log entry');   // info is level 6
logger.log('debug', 'this is the second log entry');  // debug is level 7, this will be omitted by our filter
logger.log('info',  'this is the third log entry');   // info is level 6

// Outputs
// {"args":["this is the first log entry"],"date":"2013-04-25T08:48:38.941Z","levelCode":6,"levelName":"info","line":"9","method":"Object.","file":"/Users/balupton/Projects/caterpillar-filter/example.js"}
// {"args":["this is the third log entry"],"date":"2013-04-25T08:48:38.948Z","levelCode":6,"levelName":"info","line":"11","method":"Object.","file":"/Users/balupton/Projects/caterpillar-filter/example.js"}

// Import
var logger = new require('caterpillar').createLogger();
var human = new require('./').createHuman();

// Pipe logger output to our human interface, then our human interface output to stdout
logger.pipe(human).pipe(process.stdout);

// Log
logger.log('warn',  'this is the first log entry');
// warn:  this is the first log entry
logger.log('info', 'this is the second log entry');
// info: this is the second log entry

// Wait
setTimeout(function(){
	// Set debug mode
	logger.setConfig({level:7});

LogService.prototype.initialize = function () {
    "use strict";
    var logFilter, logHuman;

    logHuman = human.createHuman();
    //create the logger
    this._logger = new Logger(this._settings.config);

    if (this._settings.loggers.console.enabled) {
        logFilter = filter.createFilter({level: (this._settings.loggers.console.debug ? 7 : 6)});
        this._logger.pipe(logFilter).pipe(logHuman).pipe(process.stdout);
    }

    if (this._settings.loggers.file.enabled) {

        if (!fs.existsSync(path.dirname(this._settings.loggers.file.filename))) {
            fs.mkdirSync(path.dirname(this._settings.loggers.file.filename));
        }

        logFilter = filter.createFilter({level: (this._settings.loggers.file.debug ? 7 : 6)});
        this._logger.pipe(logFilter).pipe(es.join('\n')).pipe(fs.createWriteStream(this._settings.loggers.file.filename, {flags: 'a'}));
    }
};

if (err && docpad.getDebugging()) {
        locale = docpad.getLocale();
        return docpad.log('warn', locale.reportError + ' ' + locale.errorFollows, ((_ref2 = err.stack) != null ? _ref2 : err.message).toString());
      }
    });
    this.trackRunnerInstance = new TaskGroup().run().on('complete', function(err) {
      var locale, _ref2;
      if (err && docpad.getDebugging()) {
        locale = docpad.getLocale();
        return docpad.log('warn', locale.trackError + ' ' + locale.errorFollows, ((_ref2 = err.stack) != null ? _ref2 : err.message).toString());
      }
    });
    if ((loggers = instanceConfig.loggers)) {
      delete instanceConfig.loggers;
    } else {
      logger = new (require('caterpillar').Logger)({
        lineOffset: 2
      });
      loggerConsole = logger.pipe(new (require('caterpillar-filter').Filter)).pipe(new (require('caterpillar-human').Human));
      loggers = {
        logger: logger,
        console: loggerConsole
      };
    }
    safefs.unlink(this.debugLogPath, function() {});
    this.setLoggers(loggers);
    this.setLogLevel(this.initialConfig.logLevel);
    this.on('log', function() {
      var args;
      args = 1 <= arguments.length ? __slice.call(arguments, 0) : [];
      return docpad.log.apply(this, args);
    });

if (err && docpad.getDebugging()) {
        locale = docpad.getLocale();
        return docpad.log('warn', locale.reportError + ' ' + locale.errorFollows, ((_ref2 = err.stack) != null ? _ref2 : err.message).toString());
      }
    });
    this.trackRunnerInstance = new TaskGroup().run().on('complete', function(err) {
      var locale, _ref2;
      if (err && docpad.getDebugging()) {
        locale = docpad.getLocale();
        return docpad.log('warn', locale.trackError + ' ' + locale.errorFollows, ((_ref2 = err.stack) != null ? _ref2 : err.message).toString());
      }
    });
    if ((loggers = instanceConfig.loggers)) {
      delete instanceConfig.loggers;
    } else {
      logger = new (require('caterpillar').Logger)({
        lineOffset: 2
      });
      loggerConsole = logger.pipe(new (require('caterpillar-filter').Filter)).pipe(new (require('caterpillar-human').Human));
      loggers = {
        logger: logger,
        console: loggerConsole
      };
    }
    safefs.unlink(this.debugLogPath, function() {});
    this.setLoggers(loggers);
    this.setLogLevel(this.initialConfig.logLevel);
    this.on('log', function() {
      var args;
      args = 1 <= arguments.length ? __slice.call(arguments, 0) : [];
      return docpad.log.apply(this, args);
    });

seperator = '\n    ';
          debugString = "→ [" + entry.timestamp + "] [" + entry.file + ":" + entry.line + "] [" + entry.method + "]";
          if (debugFormatter) {
            debugString = debugFormatter(debugString);
          }
          result = "" + messageString + seperator + debugString + "\n";
        } else {
          result = messageString + '\n';
        }
      }
      return result;
    };

    return Human;

  })(require('caterpillar').Transform);

  module.exports = {
    Human: Human,
    createHuman: function() {
      var args;
      args = 1 <= arguments.length ? __slice.call(arguments, 0) : [];
      return (function(func, args, ctor) {
        ctor.prototype = func.prototype;
        var child = new ctor, result = func.apply(child, args);
        return Object(result) === result ? result : child;
      })(Human, args, function(){});
    }
  };

}).call(this);

if (message) {
      message = JSON.stringify(message);
    }
    return next(null, message);
  };

  Filter.prototype.format = function(entry) {
    if (entry.levelNumber > this.config.level) {
      return null;
    }
    return entry;
  };

  return Filter;

})(require('caterpillar').Transform);

module.exports = {
  Filter: Filter,
  createFilter: function() {
    var args;
    args = 1 <= arguments.length ? __slice.call(arguments, 0) : [];
    return (function(func, args, ctor) {
      ctor.prototype = func.prototype;
      var child = new ctor, result = func.apply(child, args);
      return Object(result) === result ? result : child;
    })(Filter, args, function(){});
  }
};

seperator = '\n    ';
        debugString = "→ [" + entry.timestamp + "] [" + entry.file + ":" + entry.line + "] [" + entry.method + "]";
        if (debugFormatter) {
          debugString = debugFormatter(debugString);
        }
        result = "" + messageString + seperator + debugString + "\n";
      } else {
        result = messageString + '\n';
      }
    }
    return result;
  };

  return Human;

})(require('caterpillar').Transform);

module.exports = {
  Human: Human
};