[field formatters] IP should return - on null or undefined

src/ui/public/stringify/__tests__/_ip.js

@@ -2,16 +2,20 @@ import expect from 'expect.js';
 import ngMock from 'ng_mock';
 import RegistryFieldFormatsProvider from 'ui/registry/field_formats';
 describe('IP Address Format', function () {
-  let fieldFormats;
-
+  let ip;
   beforeEach(ngMock.module('kibana'));
   beforeEach(ngMock.inject(function (Private) {
-    fieldFormats = Private(RegistryFieldFormatsProvider);
+    const fieldFormats = Private(RegistryFieldFormatsProvider);
+    ip = fieldFormats.getInstance('ip');
   }));
 
   it('converts a value from a decimal to a string', function () {
-    let ip = fieldFormats.getInstance('ip');
     expect(ip.convert(1186489492)).to.be('70.184.100.148');
   });
 
+  it('converts null and undefined to -',  function () {
+    expect(ip.convert(null)).to.be('-');
+    expect(ip.convert(undefined)).to.be('-');
+  });
+
 });

src/ui/public/stringify/types/ip.js

@@ -13,6 +13,7 @@ export default function IpFormatProvider(Private) {
   Ip.fieldType = 'ip';
 
   Ip.prototype._convert = function (val) {
+    if (val === undefined || val === null) return '-';
     if (!isFinite(val)) return val;
 
     // shazzam!