Treat empty strings as an empty set of contacts (#10)

* entity contacts should be disregarded when check contacts are present

* treat empty string values as no contacts

lib/no_contacts.js

@@ -1,10 +1,22 @@
 function no_contacts(event) {
+    var check_contacts = [];
+    var entity_contacts = [];
+
     if (event.hasOwnProperty("check") && event.check.hasOwnProperty("labels") && event.check.labels.hasOwnProperty("contacts")) {
-        return false;
+        check_contacts = event.check.labels.contacts.split(",");
+        // filter out any elements which do not contain at least one non-whitespace character
+        check_contacts = check_contacts.filter(function(entry) { return /\S/.test(entry); });
     }
-    else if (event.hasOwnProperty("entity") && event.entity.hasOwnProperty("labels") && event.entity.labels.hasOwnProperty("contacts")) {
-        return false;
-    } else {
+
+    if (event.hasOwnProperty("entity") && event.entity.hasOwnProperty("labels") && event.entity.labels.hasOwnProperty("contacts")) {
+        entity_contacts = event.entity.labels.contacts.split(",");
+        // filter out any elements which do not contain at least one non-whitespace character
+        entity_contacts = entity_contacts.filter(function(entry) { return /\S/.test(entry); });
+    }
+
+    if (check_contacts.length == 0 && entity_contacts.length == 0) {
         return true;
+    } else {
+        return false;
     }
-}
+}

spec/no_contacts_spec.js

@@ -54,4 +54,16 @@ describe("no_contacts", function() {
 
         expect(no_contacts(event)).toBe(true);
     });
-});
+
+    it("returns true when labels are empty strings", function() {
+        var event = {
+            check: {
+                labels: {
+                    contacts: ""
+                }
+            }
+        }
+
+        expect(no_contacts(event)).toBe(true);
+    });
+});