fix: overrides as functions are properly cloned #455

libs/ng-mocks/src/lib/common/core.define-property.ts

@@ -1,13 +1,10 @@
+import helperMockService from '../mock-service/helper.mock-service';
+
 export default (instance: any, property: keyof any, value: any, enumerable = false) => {
-  // istanbul ignore else
-  if (Object.defineProperty) {
-    Object.defineProperty(instance, property, {
-      configurable: true,
-      enumerable,
-      value,
-      writable: true,
-    });
-  } else {
-    instance[property] = value;
-  }
+  helperMockService.definePropertyDescriptor(instance, property, {
+    configurable: true,
+    enumerable,
+    value,
+    writable: true,
+  });
 };

libs/ng-mocks/src/lib/common/mock.ts

@@ -85,12 +85,7 @@ const applyPrototype = (instance: Mock, prototype: AnyType<any>) => {
     ...helperMockService.extractPropertiesFromPrototype(prototype),
   ]) {
     const descriptor = helperMockService.extractPropertyDescriptor(prototype, prop);
-    // istanbul ignore next
-    if (!descriptor) {
-      continue;
-    }
-    descriptor.configurable = true;
-    Object.defineProperty(instance, prop, descriptor);
+    helperMockService.definePropertyDescriptor(instance, prop, descriptor);
   }
 };
 

libs/ng-mocks/src/lib/mock-builder/promise/try-mock-provider.ts

@@ -5,8 +5,8 @@ import helperUseFactory from '../../mock-service/helper.use-factory';
 import mockProvider from '../../mock-service/mock-provider';
 import { IMockBuilderConfigMock } from '../types';
 
-const createInstance = (existing: any, instance: any, config: IMockBuilderConfigMock, isFunc: boolean): any => {
-  const params = isFunc ? { transform: instance } : instance;
+const createInstance = (existing: any, instance: any, config: IMockBuilderConfigMock, isPipeFunc: boolean): any => {
+  const params = isPipeFunc ? { transform: instance } : instance;
   if (config.precise) {
     return params;
   }
@@ -18,10 +18,10 @@ export default (def: any, defValue: Map<any, any>): void => {
   if (isNgDef(def, 'i') && defValue.has(def)) {
     const config: IMockBuilderConfigMock = ngMocksUniverse.config.get(def) || {};
     const instance = defValue.get(def);
-    const isFunc = isNgDef(def, 'p') && typeof instance === 'function';
+    const isPipeFunc = isNgDef(def, 'p') && typeof instance === 'function';
     ngMocksUniverse.builtProviders.set(
       def,
-      helperUseFactory(def, undefined, existing => createInstance(existing, instance, config, isFunc)),
+      helperUseFactory(def, undefined, existing => createInstance(existing, instance, config, isPipeFunc)),
     );
   } else if (isNgDef(def, 'i')) {
     ngMocksUniverse.builtProviders.set(def, mockProvider(def));

libs/ng-mocks/src/lib/mock-helper/mock-helper.stub.ts

@@ -5,14 +5,22 @@ export default <T = MockedFunction>(instance: any, override: any, style?: 'get'
   if (typeof override === 'string') {
     return helperMockService.mock(instance, override, style);
   }
-  for (const key of Object.getOwnPropertyNames(override)) {
-    const def = Object.getOwnPropertyDescriptor(override, key);
-    // istanbul ignore else
-    if (def) {
-      def.configurable = true;
-      Object.defineProperty(instance, key, def);
-    }
+
+  // if someone is giving us a function, then we should swap instance and overrides.
+  // so in the end the function can be called, but it also has all desired properties.
+  let correctInstance = instance;
+  let applyOverrides = override;
+  const skipProps = ['__zone_symbol__unconfigurables'];
+  if (typeof override === 'function') {
+    correctInstance = helperMockService.createClone(override);
+    applyOverrides = instance;
+    skipProps.push(...Object.getOwnPropertyNames(correctInstance));
+  }
+
+  for (const key of Object.getOwnPropertyNames(applyOverrides)) {
+    const desc = skipProps.indexOf(key) === -1 ? Object.getOwnPropertyDescriptor(applyOverrides, key) : undefined;
+    helperMockService.definePropertyDescriptor(correctInstance, key, desc);
   }
 
-  return instance;
+  return correctInstance;
 };

libs/ng-mocks/src/lib/mock-service/helper.create-clone.ts

@@ -0,0 +1,22 @@
+import helperDefinePropertyDescriptor from './helper.define-property-descriptor';
+import helperExtractMethodsFromPrototype from './helper.extract-methods-from-prototype';
+import helperExtractPropertiesFromPrototype from './helper.extract-properties-from-prototype';
+import helperExtractPropertyDescriptor from './helper.extract-property-descriptor';
+
+export default (service: any): any => {
+  const instance = function () {
+    // tslint:disable-next-line:ban-ts-ignore
+    // @ts-ignore
+    return service.apply(this, arguments);
+  };
+
+  for (const prop of [
+    ...helperExtractMethodsFromPrototype(service),
+    ...helperExtractPropertiesFromPrototype(service),
+  ]) {
+    const desc = helperExtractPropertyDescriptor(service, prop);
+    helperDefinePropertyDescriptor(instance, prop, desc);
+  }
+
+  return instance;
+};

libs/ng-mocks/src/lib/mock-service/helper.define-property-descriptor.ts

@@ -0,0 +1,26 @@
+import helperExtractPropertyDescriptor from './helper.extract-property-descriptor';
+
+export default (instance: any, prop: keyof any, desc?: PropertyDescriptor): boolean => {
+  // istanbul ignore next
+  if (!desc) {
+    return false;
+  }
+
+  // istanbul ignore else
+  if (Object.defineProperty) {
+    const sourceDesc = helperExtractPropertyDescriptor(instance, prop);
+    if (sourceDesc?.configurable === false) {
+      return false;
+    }
+
+    Object.defineProperty(instance, prop, {
+      ...desc,
+      configurable: true,
+      ...(desc.writable === false ? { writable: true } : {}),
+    });
+  } else {
+    instance[prop] = desc.value;
+  }
+
+  return true;
+};

libs/ng-mocks/src/lib/mock-service/helper.extract-property-descriptor.ts

@@ -1,4 +1,4 @@
-export default <T>(service: T, prop: string): PropertyDescriptor | undefined => {
+export default <T>(service: T, prop: keyof any): PropertyDescriptor | undefined => {
   let prototype = service;
   while (prototype && Object.getPrototypeOf(prototype) !== null) {
     const descriptor = Object.getOwnPropertyDescriptor(prototype, prop);

libs/ng-mocks/src/lib/mock-service/helper.mock-service.ts

@@ -1,4 +1,6 @@
+import helperCreateClone from './helper.create-clone';
 import helperCreateMockFromPrototype from './helper.create-mock-from-prototype';
+import helperDefinePropertyDescriptor from './helper.define-property-descriptor';
 import helperExtractMethodsFromPrototype from './helper.extract-methods-from-prototype';
 import helperExtractPropertiesFromPrototype from './helper.extract-properties-from-prototype';
 import helperExtractPropertyDescriptor from './helper.extract-property-descriptor';
@@ -20,7 +22,9 @@ getGlobal().ngMockshelperMockService = getGlobal().ngMockshelperMockService || {
     getGlobal().ngMockshelperMockService.mockFunction.customMockFunction = func;
   },
 
+  createClone: helperCreateClone,
   createMockFromPrototype: helperCreateMockFromPrototype,
+  definePropertyDescriptor: helperDefinePropertyDescriptor,
   extractMethodsFromPrototype: helperExtractMethodsFromPrototype,
   extractPropertiesFromPrototype: helperExtractPropertiesFromPrototype,
   extractPropertyDescriptor: helperExtractPropertyDescriptor,
@@ -31,7 +35,9 @@ getGlobal().ngMockshelperMockService = getGlobal().ngMockshelperMockService || {
 };
 
 export default ((): {
+  createClone: typeof helperCreateClone;
   createMockFromPrototype: typeof helperCreateMockFromPrototype;
+  definePropertyDescriptor: typeof helperDefinePropertyDescriptor;
   extractMethodsFromPrototype: typeof helperExtractMethodsFromPrototype;
   extractPropertiesFromPrototype: typeof helperExtractPropertiesFromPrototype;
   extractPropertyDescriptor: typeof helperExtractPropertyDescriptor;

libs/ng-mocks/src/lib/mock-service/helper.use-factory.ts

@@ -30,7 +30,7 @@ const applyCallback = (def: any, inst: any, callbacks: any[], injector?: Injecto
       continue;
     }
 
-    mockHelperStub(instance, override);
+    instance = mockHelperStub(instance, override);
   }
 
   return instance;

libs/ng-mocks/src/lib/mock-service/mock-provider.ts

@@ -6,25 +6,23 @@ import funcGetProvider from '../common/func.get-provider';
 import { isNgInjectionToken } from '../common/func.is-ng-injection-token';
 import ngMocksUniverse from '../common/ng-mocks-universe';
 
+import helperDefinePropertyDescriptor from './helper.define-property-descriptor';
+import helperExtractPropertyDescriptor from './helper.extract-property-descriptor';
 import helperUseFactory from './helper.use-factory';
 import { MockService } from './mock-service';
 
 const { neverMockProvidedFunction, neverMockToken } = coreConfig;
 
-const applyMissedClassProperties = (instance: any, useClass: Type<any>) => {
+const applyMissingClassProperties = (instance: any, useClass: Type<any>) => {
   const existing = Object.getOwnPropertyNames(instance);
   const child = MockService(useClass);
 
   for (const name of Object.getOwnPropertyNames(child)) {
     if (existing.indexOf(name) !== -1) {
       continue;
     }
-    const def = Object.getOwnPropertyDescriptor(child, name);
-    // istanbul ignore else
-    if (def) {
-      def.configurable = true;
-      Object.defineProperty(instance, name, def);
-    }
+    const def = helperExtractPropertyDescriptor(child, name);
+    helperDefinePropertyDescriptor(instance, name, def);
   }
 };
 
@@ -34,7 +32,7 @@ const createFactoryProvider = (provider: any, provide: any) =>
     // Magic below adds missed properties to the instance to
     // fulfill missed abstract methods.
     if (provide !== provider && Object.keys(provider).indexOf('useClass') !== -1) {
-      applyMissedClassProperties(instance, provider.useClass);
+      applyMissingClassProperties(instance, provider.useClass);
     }
 
     return instance;