get method on Observable created with fromObject wan’t returning the value that was put from set if that property was not specified in the object passed to fromObject. (#4213)

get method on Observable created with fromObject wasn’t returning the …

tests/app/data/observable-tests.ts

@@ -539,3 +539,23 @@ export function test_NestedObservableWithNullShouldNotCrash() {
     });
     TKUnit.assert(testObservable !== undefined);
 }
+
+export function test_get_set_on_observables_fromObject_without_property_in_json() {
+    const array = new ObservableArray<any>();
+    const vm = fromObject({});
+    vm.set("p", array);
+    const value1 = vm.get("p");
+    const value2 = (<any>vm).p;
+    TKUnit.assertEqual(value1, array);
+    TKUnit.assertNull(value2);
+}
+
+export function test_get_set_on_observables_fromObject_with_property_in_json() {
+    const array = new ObservableArray<any>();
+    const vm = fromObject({ p: null});
+    vm.set("p", array);
+    const value1 = vm.get("p");
+    const value2 = (<any>vm).p;
+    TKUnit.assertEqual(value1, array);
+    TKUnit.assertEqual(value2, array);
+}

tns-core-modules/data/observable/observable.ts

@@ -185,6 +185,10 @@ export class Observable implements ObservableDefinition {
 class ObservableFromObject extends Observable {
     public _map = {};
 
+    public get(name: string): any {
+        return this._map[name];
+    }
+    
     public set(name: string, value: any) {
         const currentValue = this._map[name];
         if (currentValue === value) {