support AsyncLocalStorage stored object merged into logs, breaking changes to constru...

[squeep-logger-json-console] / lib / logger.js

diff --git a/lib/logger.js b/lib/logger.js
index a040bb8ba3f9e759f3003e3af562c6c0fdc7d386..d5a0c908dae0f417832cbf0fb6864d3c0f34160c 100644 (file)
--- a/lib/logger.js
+++ b/lib/logger.js
@@ -3,36 +3,52 @@
 const jsonReplacers = require('./json-replacers');
 const dataSanitizers = require('./data-sanitizers');
 
-/**
- * Log as JSON to stdout/stderr.
- */
-
 const nop = () => { /**/ };
 
-
 class Logger {
   /**
-   * Wrap backend calls with payload normalization.
-   * @param {Object} options
-   * @param {String} options.nodeId - unique identifier for running instance, usually a uuid
-   * @param {Object} options.logger
-   * @param {String} options.logger.ignoreBelowLevel - minimum level to log
+   * @typedef {Object} ConsoleLike
+   * @property {Function(...):void} error
+   * @property {Function(...):void} warn
+   * @property {Function(...):void} info
+   * @property {Function(...):void} log
+   * @property {Function(...):void} debug
+   */
+  /**
+   * @typedef {Object} LoggerOptions
+   * @property {String} ignoreBelowLevel - minimum level to log, e.g. 'info'
    */
-  constructor(options) {
+  /**
+   * Wrap backend calls with payload normalization and metadata.
+   * @param {LoggerOptions} options
+   * @param {Object} commonObject - object to be merged into logged json
+   * @param {AsyncLocalStorage} asyncLocalStorage - async storage for an object to be merged into logged json
+   * @param {ConsoleLike} backend - default is console
+   */
+  constructor(options, commonObject, asyncLocalStorage, backend) {
     const logLevels = Object.keys(Logger.nullLogger);
-    const ignoreBelowLevel = options && options.logger && options.logger.ignoreBelowLevel || 'debug';
-    this.backend = console;
-    this.nodeId = options.nodeId;
+    const ignoreBelowLevel = options?.ignoreBelowLevel || 'debug';
+    this.backend = backend || console;
+    this.commonObject = commonObject || {};
     this.jsonReplacers = Object.values(jsonReplacers);
     this.dataSanitizers = Object.values(dataSanitizers);
 
+    if (asyncLocalStorage) {
+      // Override the class getter.
+      Object.defineProperty(this, 'asyncLogObject', {
+        enumerable: true,
+        get: asyncLocalStorage.getStore.bind(asyncLocalStorage),
+      });
+    }
+
     if (!logLevels.includes(ignoreBelowLevel)) {
       throw new RangeError(`unrecognized minimum log level '${ignoreBelowLevel}'`);
     }
     const ignoreLevelIdx = logLevels.indexOf(ignoreBelowLevel);
     logLevels.forEach((level) => {
+      const includeBackendLevel = (logLevels.indexOf(level) > ignoreLevelIdx) && this.backend[level]; // eslint-disable-line security/detect-object-injection
       // eslint-disable-next-line security/detect-object-injection
-      this[level] = (logLevels.indexOf(level) > ignoreLevelIdx) ?
+      this[level] = (includeBackendLevel) ?
         nop :
         (...args) => this.backend[level](this.payload(level, ...args)); // eslint-disable-line security/detect-object-injection
     });
@@ -54,6 +70,16 @@ class Logger {
   }
 
 
+  /**
+   * Default of empty object when no asyncLocalStorage is defined.
+   * Overridden on instance when asyncLocalStorage is defined.
+   */
+  // eslint-disable-next-line class-methods-use-this
+  get asyncLogObject() {
+    return {};
+  }
+
+
   /**
    * Structure all expected log data into JSON string.
    * @param {String} level
@@ -72,7 +98,7 @@ class Logger {
 
     const now = new Date();
     return JSON.stringify({
-      nodeId: this.nodeId,
+      ...this.commonObject,
       timestamp: now.toISOString(),
       timestampMs: now.getTime(),
       level: level,
@@ -80,6 +106,7 @@ class Logger {
       message: message || '',
       data: data || {},
       ...(other.length && { other }),
+      ...this.asyncLogObject,
     }, this.jsonReplacer.bind(this));
   }