Fix SplunkHEC not logging because of non-JSON body (#81)

* Use `json-stringify-safe` to stringify splunk body
* Add logging when there is an error logging to splunk

package.json

@@ -13,6 +13,7 @@
   },
   "dependencies": {
     "isomorphic-fetch": "^2.2.1",
+    "json-stringify-safe": "^5.0.1",
     "request": "^2.83.0",
     "winston": "^2.4.0"
   },

src/lib/transports/splunkHEC.js

@@ -1,8 +1,21 @@
 import winston from 'winston';
-import { inspect } from 'util';
+import stringify from 'json-stringify-safe';
 import formatHEC from '../formatHEC';
+
 const https = require('https');
 
+const throwIfNotOk = res => {
+	const { ok, status, url } = res;
+	if (!ok) {
+		return res.json()
+			.then(errorBody => {
+				console.error('Fetch error:', status, url, errorBody); // eslint-disable-line no-console
+				throw errorBody;
+			});
+	}
+	return res;
+};
+
 class SplunkHEC extends winston.Transport {
 
 	log (level, message, meta) {
@@ -25,8 +38,13 @@ class SplunkHEC extends winston.Transport {
 			},
 			pool: httpsAgent,
 			timeout: 3000,
-			body: inspect(data)
-		}).catch(() => {});
+			body: stringify(data)
+		})
+			.then(throwIfNotOk)
+			.catch((error) => {
+				/* eslint no-console: 0 */
+				console.log('Error logging to splunk', error, data);
+			});
 	};
 
 }

test/lib/transports/splunkHEC.test.js

@@ -1,4 +1,5 @@
 const chai = require('chai');
+const { expect } = chai;
 chai.should();
 
 require('isomorphic-fetch');
@@ -65,12 +66,37 @@ describe('SplunkHEC', () => {
 		it('should send a log if data is circularly referenced', () => {
 			nock('https://http-inputs-financialtimes.splunkcloud.com')
 				.post('/services/collector/event')
-				.reply(201, { text: 'Successful request', code: 0 });
+				// NOTE: Returning requestBody for further tests
+				.reply(201, (uri, requestBody) => {
+					return requestBody;
+				});
 
 			const splunkHECTransport = new SplunkHEC();
 			const circularData = { field: 'value' };
 			circularData.circularData = circularData;
-			return splunkHECTransport.log('info', 'a message', circularData);
+			return splunkHECTransport.log('info', 'a message', circularData)
+				// Process JSON, to check returned requestBody
+				.then(res => res.json())
+				.then(data => {
+					expect(data).to.be.an('object');
+				});;
+		});
+
+		it('sent log body should be JSON.parse-able', () => {
+			nock('https://http-inputs-financialtimes.splunkcloud.com')
+				.post('/services/collector/event')
+				// NOTE: Returning requestBody for further tests
+				.reply(201, (uri, requestBody) => {
+					return requestBody;
+				});
+
+			const splunkHECTransport = new SplunkHEC();
+			return splunkHECTransport.log('info', 'a message', { field: 'value' })
+				// Process JSON, to check returned requestBody
+				.then(res => res.json())
+				.then(data => {
+					expect(data).to.be.an('object');
+				});
 		});
 	});