super simple json log for fe

ssjl.js

#!/usr/bin/env node
'use strict';
class Log {
  constructor(options) {
    options = options || {};
    this.level = 'off';
    this.levels = {
      debug: 0,
      info: 1,
      warn: 2,
      error: 3,
      off: 4
    };
    Object.assign(this, options);
    for (const level of Object.keys(this.levels)) {
      this[level] = (o, spaces = this.spaces) => {
        if (this.levels[level] >= this.levels[this.level]) {
          const sf = JSON.stringify(o, null, spaces);
          if (sf.startsWith('{')) {
            console.log(sf);
          }
          else {
            o = { message: o };
            console.log(JSON.stringify(o, null, spaces));
          }
        }
      };
    }
  }
}
const log = new Log({ level: 'info', spaces: 7 });
log.debug({ msg: 'debug!' });
log.info(1, 3);
log.warn({ msg: 'warn!' });
log.error({ msg: 'error!' });

const log2 = new Log({ level: 'error' });
log2.debug({ msg: 'debug!' });
log2.info(1, 3);
log2.warn({ msg: 'warn!' });
log2.error({ msg: 'error!' });