Allow for proper nesting for getting data for lists and grids (#671)

* Changed the list helper getData function to set the result to null if the final part was undefined so that nesting works correctly.

* Added unit tests

src/modules/list/helpers.spec.ts

@@ -32,6 +32,33 @@ describe('list helpers', () => {
     expect(result).toBeNull();
   });
 
+  it('returns property when selector is a nested selector', () => {
+    let data: any = {
+      myResults: { nestedValue: 'expected'},
+      otherResult: 'nothing'
+    };
+    let result = getData(data, 'myResults.nestedValue');
+    expect(result).toBe('expected');
+  });
+
+  it('returns property when selector is a nested selector that does not exits', () => {
+    let data: any = {
+      myResults: {},
+      otherResult: 'nothing'
+    };
+    let result = getData(data, 'myResults.nestedValue');
+    expect(result).toBeNull();
+  });
+
+  it('returns property when selector is a nested selector that is undefined', () => {
+    let data: any = {
+      myResults: { nestedValue: undefined },
+      otherResult: 'nothing'
+    };
+    let result = getData(data, 'myResults.nestedValue');
+    expect(result).toBeNull();
+  });
+
   it('returns null when empty string selector defined', () => {
     let data = {
       myResult: 'something',

src/modules/list/helpers.ts

@@ -11,11 +11,9 @@ export function getData(item: any, selector: string): any {
   if (resultFieldParts.length > 0) {
     for (let index = 0; index < resultFieldParts.length; index++) {
     let part = resultFieldParts[index];
-      if (result[part] === undefined) {
-        break;
-      }
       /* tslint:disable */
-      else if (result[part] === null) {
+      /* istanbul ignore else */
+      if (result[part] === null || result[part] === undefined) {
         result = null;
         break;
       }