Bugfix/163 empty description (#164)

* Fix test description to match, what actually is happening

* Allow empty description

Fixed issue which results in a javascript error if description was empty.

Fixes #163

Author: tomtomsen

src/rules/description-format.js

@@ -19,6 +19,7 @@ const lint = (packageJsonData, severity, config) => {
   if (
     config.hasOwnProperty('requireCapitalFirstLetter') &&
     config.requireCapitalFirstLetter &&
+    description.length > 0 &&
     description[0] !== description[0].toUpperCase()
   ) {
     return new LintIssue(

test/unit/rules/description-format.test.js

@@ -63,8 +63,22 @@ describe('description-format Unit Tests', () => {
     });
   });
 
+  describe('when package.json has empty node', () => {
+    test('true should be returned', () => {
+      const packageJsonData = {
+        description: ''
+      };
+      const config = {
+        requireCapitalFirstLetter: true
+      };
+      const response = lint(packageJsonData, 'error', config);
+
+      expect(response).toBe(true);
+    });
+  });
+
   describe('when package.json has node with correct format', () => {
-    test('LintIssue object should be returned', () => {
+    test('true should be returned', () => {
       const packageJsonData = {
         description: 'My description.'
       };