Fixing metadata storing (#219)

* adding dotenv

* fixing declaration

* fixing meta key

* rollback dts change

* fixing saving meta data

* filtering empty objects

* Update README.md

* fixing variable def

* accepting label from log entry

* label handled on transport level only

.gitignore

@@ -1,3 +1,4 @@
 node_modules
 npm-debug.log
 .idea
+.env

README.md

@@ -1,10 +1,10 @@
-# winston
+# winston-mongodb
 
 A MongoDB transport for [winston][0].
 
-Current version supports only mongodb driver version 3.x and winston 3.x. If you want to use
-winston-mongodb with mongodb version 1.4.x use winston-mongodb <1.x. For mongodb 2.x use
-winston-mongodb <3.x.
+Current version supports only mongodb driver version 3.x and newer and winston 3.x and newer.
+If you want to use winston-mongodb with mongodb version 1.4.x use winston-mongodb <1.x. 
+For mongodb 2.x use winston-mongodb <3.x.
 
 ## Motivation
 `tldr;?`: To break the [winston][0] codebase into small modules that work
@@ -17,51 +17,61 @@ and a File is overkill.
 
 ## Usage
 ``` js
-  var winston = require('winston');
+const winston = require('winston');
+// Requiring `winston-mongodb` will expose winston.transports.MongoDB`
+require('winston-mongodb');
 
-  /**
-   * Requiring `winston-mongodb` will expose
-   * `winston.transports.MongoDB`
-   */
-  require('winston-mongodb');
+const log = winston.createLogger({
+  level: 'info',
+  transports: [
+    // write errors to console too
+    new winston.transports.Console({format: winston.format.simple(), level:'error'})
+  ],
+});
+
+// logging to console so far
+log.info('Connecting to database...');
+
+const MongoClient = require('mongodb').MongoClient;
+const url = "mongodb://localhost:27017/mydb";
+
+const client = new MongoClient(url);
+await client.connect();
+
+const transportOptions = {
+  db: await Promise.resolve(client),
+  collection: 'log'
+};
+
+log.add(new winston.transports.MongoDB(transportOptions));
+
+// following entry should appear in log collection and will contain
+// metadata JSON-property containing url field
+log.info('Connected to database.',{url});
 
-  winston.add(new winston.transports.MongoDB(options));
 ```
 
-The MongoDB transport takes the following options. 'db' is required:
-
-* __level:__ Level of messages that this transport should log, defaults to
-'info'.
-* __silent:__ Boolean flag indicating whether to suppress output, defaults to
-false.
-* __db:__ MongoDB connection uri, pre-connected `MongoClient` object or promise
-which resolves to a pre-connected `MongoClient` object.
-* __dbName:__ The database name to connect to, defaults to DB name based on 
-connection URI if not provided, ignored if using a pre-connected mongoose connection.
-* __options:__ MongoDB connection parameters (optional, defaults to
-`{poolSize: 2, autoReconnect: true, useNewUrlParser: true}`).
-* __collection__: The name of the collection you want to store log messages in,
-defaults to 'log'.
-* __storeHost:__ Boolean indicating if you want to store machine hostname in
-logs entry, if set to true it populates MongoDB entry with 'hostname' field,
-which stores os.hostname() value.
-* __label:__ Label stored with entry object if defined.
-* __name:__ Transport instance identifier. Useful if you need to create multiple
-MongoDB transports.
-* __capped:__ In case this property is true, winston-mongodb will try to create
-new log collection as capped, defaults to false.
-* __cappedSize:__ Size of logs capped collection in bytes, defaults to 10000000.
-* __cappedMax:__ Size of logs capped collection in number of documents.
-* __tryReconnect:__ Will try to reconnect to the database in case of fail during
-initialization. Works only if __db__ is a string. Defaults to false.
-* __decolorize:__ Will remove color attributes from the log entry message,
-defaults to false.
-* __leaveConnectionOpen:__ Will leave MongoClient connected after transport shut down.
-* __metaKey:__ Configure which key is used to store metadata in the logged info object.
-Defaults to `'metadata'` to remain compatible with the [metadata format](https://github.com/winstonjs/logform/blob/master/examples/metadata.js)
-* __expireAfterSeconds:__ Seconds before the entry is removed. Works only if __capped__ is not set.
-
-*Metadata:* Logged as a native JSON object in 'meta' property.
+The MongoDB transport takes the following options. Only option `db` is required:
+
+| Option |  Description                                     |
+| ------ | :----------------------------------------------- |
+| db     | **REQUIRED**. MongoDB connection uri, pre-connected `MongoClient` object or promise which resolves to a pre-connected `MongoClient` object. |
+| dbname | The database name to connect to, defaults to DB name based on connection URI if not provided, ignored if using a pre-connected connection. |
+| options| MongoDB connection parameters.<br/>Defaults to `{poolSize: 2, autoReconnect: true, useNewUrlParser: true}`). |
+| collection | The name of the collection you want to store log messages in.<br/>Defaults to `log`. |
+| level  | Level of messages that this transport should log.<br/>Defaults to `info`. |
+| silent | Boolean flag indicating whether to suppress output.<br/>Defaults to `false`. |
+| storeHost | Boolean indicating if you want to store machine hostname in logs entry, if set to true it populates MongoDB entry with 'hostname' field, which stores os.hostname() value. |
+| label  | If set to true, then label attribute content will be stored in `label` field, if detected in meta-data. |
+| name | Transport instance identifier. Useful if you need to create multiple MongoDB transports. |
+| capped | In case this property is true, winston-mongodb will try to create new log collection as capped.<br/>Defaults to `false`. |
+| cappedSize | Size of logs capped collection in bytes.<br/>Defaults to 10,000,000. |
+| cappedMax | Size of logs capped collection in number of documents. |
+| tryReconnect | Will try to reconnect to the database in case of fail during initialization. Works only if __db__ is a string.<br/>Defaults to `false`. |
+| decolorize | Will remove color attributes from the log entry message.<br/>Defaults to `false`. |
+| leaveConnectionOpen| Will leave MongoClient connected after transport shuts down. |
+| metaKey | Configure name of the field which is used to store metadata in the logged info object.<br/>Defaults to `metadata` to remain compatible with the [metadata format](https://github.com/winstonjs/logform/blob/master/examples/metadata.js) |
+| expireAfterSeconds |Seconds before the entry is removed. Works only if __capped__ is not set. |
 
 *Logging unhandled exceptions:* For logging unhandled exceptions specify
 winston-mongodb as `handleExceptions` logger according to winston documentation.

lib/winston-mongodb.d.ts

@@ -46,7 +46,7 @@ declare module 'winston-mongodb' {
        /**
         * MongoDB connection uri, pre-connected db object or promise object which will be resolved with pre-connected db object.
         *
-        * @type {(string | Promise<any>)}
+        * @type {(string | Promise<object>)}
         * @memberof MongoDBConnectionOptions
         */
        db: string | Promise<any>;

lib/winston-mongodb.js

@@ -217,12 +217,20 @@ MongoDB.prototype.log = function(info, cb) {
     }
     const decolorizeRegex = new RegExp(/\u001b\[[0-9]{1,2}m/g);
     let entry = { timestamp: new Date(), level: (this.decolorize) ? info.level.replace(decolorizeRegex, '') : info.level };
-    let message = util.format(info.message, ...(info.splat || []));
-    entry.message = (this.decolorize) ? message.replace(decolorizeRegex, '') : message;
-    entry.meta = helpers.prepareMetaData(info[this.metaKey]);
+    let msg = util.format(info.message, ...(info.splat || []));
+    entry.message = (this.decolorize) ? msg.replace(decolorizeRegex, '') : msg;
+    // get 'meta' object from info object - as per winston doc: Properties besides level and message are considered as "meta".
+    const {level, message, ...meta} = info;
+    // prepare meta object for storage
+    const metaData = helpers.prepareMetaData(meta);
+    // if metadata is not empty object add it to entry - makes no sense to store empty object
+    if (Object.keys(metaData).length > 0) {
+      entry[this.metaKey] = metaData;
+    }
     if (this.storeHost) {
       entry.hostname = this.hostname;
     }
+
     if (this.label) {
       entry.label = this.label;
     }

package.json

@@ -41,6 +41,7 @@
   },
   "devDependencies": {
     "abstract-winston-transport": "~0.5.1",
+    "dotenv": "^16.1.4",
     "mocha": "^10.2.0",
     "mongoose": "^5.10.5",
     "winston": "^3.3.3"

test/winston-mongodb-test.js

@@ -6,6 +6,7 @@
  * @author [email protected] (Yurij Mikhalevich)
  */
 'use strict';
+require('dotenv').config();
 const mongodb = require('mongodb');
 const mongoose = require('mongoose');
 const test_suite = require('abstract-winston-transport');