@treecg/curation/src/logging/Logger.ts

This library implements a class (Curator) with methods to curate an announcement LDES in LDP.

/***************************************
 * Title: Logger
 * Description: Simple logger class
 * Author: Wout Slabbinck (wout.slabbinck@ugent.be)
 * Created on 02/12/2021
 *****************************************/
import log from "loglevel";
import prefix from "loglevel-plugin-prefix";

export class Logger {
  private readonly logger;

  constructor(loggable: Instance | string, level?: string | undefined) {
    const label = typeof loggable === 'string' ? loggable : loggable.constructor.name;
    level = level && isLogLevel(level) ? level : 'info';
    log.setDefaultLevel('info');
    if (level && isLogLevel(level)) {
      log.setLevel(level as log.LogLevelDesc);
    }
    prefix.reg(log);
    prefix.apply(log, {
      template: '%t [%n] %l:',
      levelFormatter(level) {
        return level;
      },
      nameFormatter(name) {
        return name || 'global';
      },
      timestampFormatter(date) {
        return date.toISOString();
      },
    });
    this.logger = log.getLogger(label);
  }

  public error(message: string): void {
    this.logger.error(message);
  }

  public warn(message: string): void {
    this.logger.warn(message);
  }
  public info(message: string): void {
    this.logger.info(message);
  }
  public debug(message: string): void {
    this.logger.debug(message);
  }
  public trace(message: string): void {
    this.logger.trace(message);
  }
}

function isLogLevel(value: string): boolean {
  value = value.toUpperCase();
  return Object.keys(log.levels).includes(value);
}

interface Instance {
  constructor: { name: string };
}