git.squeep.com Git - websub-hub/blob - src/logger.js

   1 'use strict';
   2
   3 /**
   4  * Log as JSON to stdout/stderr.
   5  */
   6
   7 const common = require('./common');
   8
   9 // This is uncomfortable, but is the simplest way to let logging work for BigInts.
  10 // TODO: revisit with better solution
  11 BigInt.prototype.toJSON = function() {
  12   return this.toString();
  13 }
  14
  15 // Also uncomfortable, but let us log Errors reasonably.
  16 Object.defineProperty(Error.prototype, 'toJSON', {
  17   configurable: true,
  18   writable: true, // Required to let Axios override on its own Errors
  19   value: function () {
  20     const result = {};
  21     const dupKey = function (key) {
  22       // eslint-disable-next-line security/detect-object-injection
  23       result[key] = this[key];
  24     };
  25     Object.getOwnPropertyNames(this)
  26       // .filter((prop) => !(prop in []))
  27       .forEach(dupKey, this);
  28     return result;
  29   },
  30 });
  31
  32 class Logger {
  33   /**
  34    * Wrap backend calls with payload normalization.
  35    * @param {Object} options
  36    * @param {*} backend Console style interface
  37    * @param {Object} options.logger
  38    * @param {String} options.logger.ignoreBelowLevel minimum level to log
  39    * @param {String} options.nodeId
  40    */
  41   constructor(options, backend = console) {
  42     const logLevels = Object.keys(common.nullLogger);
  43     const ignoreBelowLevel = options && options.logger && options.logger.ignoreBelowLevel || 'debug';
  44     this.nodeId = options.nodeId;
  45
  46     if (!logLevels.includes(ignoreBelowLevel)) {
  47       throw new RangeError(`unrecognized minimum log level '${ignoreBelowLevel}'`);
  48     }
  49     const ignoreLevelIdx = logLevels.indexOf(ignoreBelowLevel);
  50     logLevels.forEach((level) => {
  51       // eslint-disable-next-line security/detect-object-injection
  52       this[level] = (logLevels.indexOf(level) > ignoreLevelIdx) ?
  53         common.nop :
  54         this.levelTemplateFn(backend, level);
  55     });
  56   }
  57
  58   levelTemplateFn(backend, level) {
  59     // eslint-disable-next-line security/detect-object-injection
  60     if (!(level in backend) || typeof backend[level] !== 'function') {
  61       return common.nop;
  62     }
  63
  64     // eslint-disable-next-line security/detect-object-injection
  65     return (...args) => backend[level](this.payload(level, ...args));
  66   }
  67
  68   payload(level, scope, message, data, ...other) {
  69     const now = new Date();
  70     return JSON.stringify({
  71       nodeId: this.nodeId,
  72       timestamp: now.toISOString(),
  73       timestampMs: now.getTime(),
  74       level: level,
  75       scope: scope || '[unknown]',
  76       message: message || '',
  77       data: data || {},
  78       ...(other.length && { other }),
  79     });
  80   }
  81 }
  82
  83 module.exports = Logger;