Simply logger for React App using TypeScript

log.ts

const LOG_LEVEL_FROM_ENV = process?.env?.REACT_APP_LOG_LEVEL ?? 'silent';

/**
 * Supported logging levels by names, the index is the level number.
 */
export const LOG_LEVEL_NAMES = ['trace', 'debug', 'info', 'warn', 'error', 'silent'];

/**
 * Lightweight logger with minimal log level restrictions
 * @class Log
 */
class Log {
  private readonly _level: number;

  constructor(private readonly _name: string) {
    this._level = Log.levelNameToLevelNumber(_name);
  }

  static levelNameToLevelNumber(levelName: string = LOG_LEVEL_FROM_ENV): number {
    return LOG_LEVEL_NAMES.indexOf(levelName?.toLowerCase());
  }

  get level() {
    return this._level;
  }

  get name() {
    return this._name;
  }

  public notify(logLevel: string, ...args: unknown[]): void {
    const level = Log.levelNameToLevelNumber(logLevel);
    if (level < this._level) {
      return; // We don't need to notify or log anything
    }

    /* eslint-disable no-console */
    switch (level) {
      case 0: // trace
        console.trace(...args);
        break;
      case 1: // debug
        console.debug(...args);
        break;
      case 2: // info
        console.info(...args);
        break;
      case 3: // warn
        console.warn(...args);
        break;
      case 4: // error
        console.error(...args);
        break;
      case 5: // critical
        console.error(...args);
        break;
      default:
        // Do nothing
        break;
    }
    /* eslint-enable no-console */
  }

  public trace(...args: unknown[]): void {
    this.notify(LOG_LEVEL_NAMES[0], ...args);
  }

  public debug(...args: unknown[]): void {
    this.notify(LOG_LEVEL_NAMES[1], ...args);
  }

  public info(...args: unknown[]): void {
    this.notify(LOG_LEVEL_NAMES[2], ...args);
  }

  public warn(...args: unknown[]): void {
    this.notify(LOG_LEVEL_NAMES[3], ...args);
  }

  public error(...args: unknown[]): void {
    this.notify(LOG_LEVEL_NAMES[4], ...args);
  }

  public critical(...args: unknown[]): void {
    this.notify(LOG_LEVEL_NAMES[5], ...args);
  }

  public log(...args: unknown[]): void {
    this.notify(this._name, ...args);
  }
}

export const log = new Log(LOG_LEVEL_FROM_ENV);

// eslint-disable-next-line no-console
console.log(`Log level: ${log.level} aka "${log.name}"`);