fix(mock): allow assigning read-only properties

Author: dirkluijk

projects/spectator/jest/test/spy-object/spy-object.spec.ts

@@ -9,14 +9,22 @@ describe('SpyObject', () => {
     person.sayHi.andReturn('Bye!');
   });
 
-  it('should keep getters/setters', () => {
+  it('should enable spying on properties', () => {
     const person = createSpyObject(Person);
     person.birthYear = 1990;
     jest.spyOn(person, 'age', 'get').mockReturnValue(29);
 
     expect(person.age).toBe(29);
   });
 
+  it('should enable setting properties by just assigning', () => {
+    const person = createSpyObject(Person);
+    person.birthYear = 1990;
+    (person as any).age = 29;
+
+    expect(person.age).toBe(29);
+  });
+
   it('should allow setting properties', () => {
     const person = createSpyObject(Person);
 

projects/spectator/src/lib/mock.ts

@@ -55,7 +55,8 @@ export function installProtoMethods<T>(mock: any, proto: any, createSpyFn: Funct
       mock[key] = createSpyFn(key);
     } else if (descriptor.get && !mock.hasOwnProperty(key)) {
       Object.defineProperty(mock, key, {
-        get: () => null
+        set: value => (mock[`_${key}`] = value),
+        get: () => mock[`_${key}`]
       });
     }
   }

projects/spectator/test/spy-object/spy-object.spec.ts

@@ -17,6 +17,14 @@ describe('SpyObject', () => {
     expect(person.age).toBe(29);
   });
 
+  it('should enable setting properties by just assigning', () => {
+    const person = createSpyObject(Person);
+    person.birthYear = 1990;
+    (person as any).age = 29;
+
+    expect(person.age).toBe(29);
+  });
+
   it('should allow setting properties', () => {
     const person = createSpyObject(Person);