stringify: add support for nested errors with multiple properties

package.json

@@ -24,7 +24,8 @@
     "iron-mask": "1.0.2",
     "moment-timezone": "^0.5.13",
     "pokeprop": "^1.0.0",
-    "ramda": "^0.23.0"
+    "ramda": "^0.23.0",
+    "serialize-error": "^7.0.1"
   },
   "devDependencies": {
     "ava": "^2.4.0",

src/utils.js

@@ -1,18 +1,17 @@
 const R = require('ramda')
 const pokeprop = require('pokeprop')
 const circularJSON = require('circular-json')
+const { serializeError } = require('serialize-error')
 
 const parseStringToJSON = chunk => (
   Promise.resolve(chunk)
     .then(JSON.parse)
-    .catch(err => chunk)
+    .catch(_ => chunk)
 )
 
-const buildErrorObject = R.pick(['message', 'stack'])
-
 const stringify = log => {
   if (R.is(String, log)) return log
-  if (R.is(Error, log.message)) log.message = buildErrorObject(log.message)
+  if (R.is(Error, log.message)) log.message = serializeError(log.message)
   return circularJSON.stringify(log)
 }
 

test/unit/utils.js

@@ -25,18 +25,47 @@ test('stringify: with a invalid JSON object', t => {
 })
 
 test('stringify: with a valid error object', t => {
+  const err = new Error('Error Message')
+
   const logStringified = utils.stringify({
     id: 1,
-    message: new Error('Error Message')
+    message: err
   })
 
   const logObject = JSON.parse(logStringified)
   const logError = logObject.message
 
-  t.is(logError.message, 'Error Message')
+  t.is(logError.message, err.message)
   t.true(logError.stack.includes('Error: Error Message'))
 })
 
+test('stringify: with a valid nested error object with multiple properties', t => {
+  const innerErr = new Error('Inner error message')
+  innerErr.username = 'foo'
+  innerErr.isValidUsername = true
+
+  const err = new Error('Error message')
+  err.cause = innerErr
+  err.correlationId = '4ac1-b431-cab1-4c1a'
+
+  const logStringified = utils.stringify({
+    id: 1,
+    message: err
+  })
+
+  const logObject = JSON.parse(logStringified)
+  const logError = logObject.message
+
+  t.is(logError.message, err.message)
+  t.is(logError.correlationId, err.correlationId)
+  t.true(logError.stack.includes('Error: Error message'))
+
+  t.is(logError.cause.message, innerErr.message)
+  t.is(logError.cause.username, innerErr.username)
+  t.is(logError.cause.isValidUsername, innerErr.isValidUsername)
+  t.true(logError.cause.stack.includes('Error: Inner error message'))
+})
+
 test('generateLogLevel: with status code 400', t => {
   t.is(utils.generateLogLevel(400), 'warn')
 })