Fix: log Errors on winston ^2.3.1

helpers/cloneErrorProxy.js

@@ -0,0 +1,45 @@
+'use strict'
+
+// I copied LOGGING_LEVELS from src/helpers/assertLevel.js
+// because this file is going to be deprecated when the bug is solved on winston.
+const LOGGING_LEVELS = [
+  'error',
+  'warn',
+  'info',
+  'verbose',
+  'debug',
+  'silly',
+]
+
+// FIX: because winston from versions 2.3.1 until 2.4.0 does not log Error objects.
+const cloneErrorProxy = logger => {
+  const handler = {
+    get: (target, name) => {
+      // If the target[name] is a logging level we should verify if any
+      // of the arguments is an Error.
+      if (LOGGING_LEVELS.indexOf(name) > -1) {
+        return (...loggerArgs) => {
+          const validArgs = loggerArgs
+            .map(loggerArg => {
+              if (loggerArg instanceof Error) {
+                // Loosely "Clone" Error Objects
+                return {
+                  message: loggerArg.message,
+                  stack: loggerArg.stack,
+                }
+              }
+              return loggerArg
+            })
+
+          return target[name](...validArgs)
+        }
+      }
+
+      return target[name]
+    },
+  }
+
+  return new Proxy(logger, handler)
+}
+
+module.exports = cloneErrorProxy

index.js

@@ -3,13 +3,20 @@
 const glob = require('glob')
 const winston = require('winston')
 
+const cloneErrorProxy = require('./helpers/cloneErrorProxy')
+
 const isTransport = t => t && t.log
 const transports = glob.sync('./transports/*.js', { cwd: __dirname })
   .map(require)
   .filter(isTransport)
 
-const logger = new (winston.Logger)({
+const unwrappedLogger = new (winston.Logger)({
   transports,
 })
 
+// We are proxying winston logger because versions from 2.3.0 until 2.4.0
+// does not log Error objects. The proxy is going to be DEPRECATED
+// after winston solves its bug.
+const logger = cloneErrorProxy(unwrappedLogger)
+
 module.exports = logger

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@invisible/logger",
-  "version": "0.0.12",
+  "version": "0.0.13",
   "description": "Invisible Logging Wrapper",
   "main": "index.js",
   "scripts": {