Merge pull request #810 from LiskHQ/807-cannot-read-status-code-of-un…

…defined

Avoid crash when response not present - Closes #807

lib/api/blocks.js

@@ -94,6 +94,31 @@ module.exports = function (app) {
 		};
 	}
 
+	function getDelegateCall(publicKey, cb) {
+		if (!publicKey) {
+			return cb('Missing/Invalid publicKey parameter');
+		}
+
+		let errorMessage = null;
+		let delegate = null;
+
+		return request.get({
+			url: `${app.get('lisk address')}/delegates?publicKey=${publicKey}`,
+			json: true,
+		}, (err, response, body) => {
+			const statusCode = response && response.statusCode;
+			const responseData = body && body.data;
+
+			if (err || statusCode !== 200) {
+				errorMessage = err || 'Response was unsuccessful';
+			} else if (Array.isArray(responseData) && responseData.length > 0) {
+				delegate = delegatesMapper(responseData[0]);
+			}
+
+			return cb(errorMessage, delegate);
+		});
+	}
+
 	function Blocks() {
 		this.offset = function (n) {
 			n = parseInt(n, 10);
@@ -104,19 +129,12 @@ module.exports = function (app) {
 			return n;
 		};
 
-		this.getDelegate = function (result, cb) {
-			const block = result;
+		this.getDelegate = function (block, cb) {
+			const { generatorPublicKey } = block;
 
-			return request.get({
-				url: `${app.get('lisk address')}/delegates?publicKey=${block.generatorPublicKey}`,
-				json: true,
-			}, (err, response, body) => {
-				if (response.statusCode === 200 && body && Array.isArray(body.data) && body.data[0]) {
-					block.delegate = delegatesMapper(body.data[0]);
-				} else {
-					block.delegate = null;
-				}
-				return cb(null, result);
+			getDelegateCall(generatorPublicKey, (err, delegate) => {
+				block.delegate = delegate;
+				return cb(null, block);
 			});
 		};
 
@@ -214,24 +232,11 @@ module.exports = function (app) {
 			});
 		};
 
-		/* eslint-disable consistent-return */
 		this.getDelegate = function (result, cb) {
-			if (!result.block) {
-				return cb(null, result);
-			}
-			const block = result.block;
+			const { block } = result;
 
-			request.get({
-				url: `${app.get('lisk address')}/delegates?publicKey=${block.generatorPublicKey}`,
-				json: true,
-			}, (err, response, body) => {
-				if (err || response.statusCode !== 200) {
-					return cb(err || 'Response was unsuccessful');
-				} else if (body && Array.isArray(body.data) && body.data.length > 0) {
-					block.delegate = delegatesMapper(body.data[0]);
-				} else {
-					block.delegate = null;
-				}
+			return getDelegateCall(block.generatorPublicKey, (err, delegate) => {
+				block.delegate = delegate;
 				return cb(null, result);
 			});
 		};