Handle errors with circular references in done (#41)

* handle errors with circular references in done

* fix linting errors

Author: JDragovichAlertLogic

al_aws_collector.js

@@ -10,6 +10,7 @@
  */
 'use strict';
 
+const util = require('util');
 const AWS = require('aws-sdk');
 const moment = require('moment');
 const zlib = require('zlib');
@@ -119,7 +120,26 @@ class AlAwsCollector {
     done(error) {
         let context = this._invokeContext;
         if (error) {
-            return context.fail(error);
+            // The lambda context tires to stringify errors, so we should check if they can be stringified before we pass them to the context
+            try{
+                const stringifiedError = JSON.stringify(error);
+                return context.fail(error);
+            }
+            catch (stringifyError){
+                // Can't stringify the whole error, so lets try and get some useful info from it
+                let errorString;
+
+                if (error.toJSON){
+                    errorString = error.toJSON();
+                } else if (error.message){
+                    errorString = error.message;
+                } else {
+                    // when all else fails, stringify it the gross way with inspect
+                    errorString = util.inspect(error);
+                }
+
+                return context.fail(errorString);
+            }
         } else {
             return context.succeed();
         }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@alertlogic/al-aws-collector-js",
-  "version": "2.0.4",
+  "version": "2.0.5",
   "license": "MIT",
   "description": "Alert Logic AWS Collector Common Library",
   "repository": {

test/al_aws_collector_test.js

@@ -603,6 +603,71 @@ describe('al_aws_collector tests', function() {
         });
     });
 
+    describe('done() function', () => {
+        var collector;
+
+        it('calls success when there is no error', () => {
+
+            const testContext = {
+                succeed: () => true,
+                fail: () => false
+            };
+
+            collector = new AlAwsCollector(
+                testContext,
+                'cwe',
+                AlAwsCollector.IngestTypes.SECMSGS,
+                '1.0.0',
+                colMock.AIMS_TEST_CREDS
+            );
+
+            const doneResult = collector.done();
+            assert.ok(doneResult);
+        });
+
+        it('returns errors that can be stringified in their raw state', () => {
+            const stringifialbleError = {
+                foo: "bar"
+            };
+            const testContext = {
+                succeed: () => true,
+                fail: (error) => error
+            };
+
+            collector = new AlAwsCollector(
+                testContext,
+                'cwe',
+                AlAwsCollector.IngestTypes.SECMSGS,
+                '1.0.0',
+                colMock.AIMS_TEST_CREDS
+            );
+
+            const doneResult = collector.done(stringifialbleError);
+            assert.ok(doneResult === stringifialbleError);
+        });
+
+        it('returns errors that cannot be JSON stringified as a string', () => {
+            const circRefError = {};
+            circRefError.foo = circRefError;
+            const testContext = {
+                succeed: () => true,
+                fail: (error) => error
+            };
+
+            collector = new AlAwsCollector(
+                testContext,
+                'cwe',
+                AlAwsCollector.IngestTypes.SECMSGS,
+                '1.0.0',
+                colMock.AIMS_TEST_CREDS
+            );
+
+            const doneResult = collector.done(circRefError);
+            assert.ok(doneResult !== circRefError);
+            assert.ok(typeof doneResult === 'string');
+        });
+    });
+
     describe('applyConfigChanges() function', () => {
         var object;
         var newValues;