fix: auto-spy covers pipes with default transform

lib/mock-pipe/mock-pipe.ts

@@ -7,6 +7,7 @@ import { getMockedNgDefOf } from '../common/func.get-mocked-ng-def-of';
 import { Mock } from '../common/mock';
 import { MockOf } from '../common/mock-of';
 import ngMocksUniverse from '../common/ng-mocks-universe';
+import helperMockService from '../mock-service/helper.mock-service';
 
 import { MockedPipe } from './types';
 
@@ -17,24 +18,20 @@ export function MockPipes(...pipes: Array<Type<PipeTransform>>): Array<Type<Pipe
   return pipes.map(pipe => MockPipe(pipe, undefined));
 }
 
-const defaultTransform = (): void => undefined;
-
-const getMockClass = (pipe: Type<any>, transform: PipeTransform['transform']): Type<any> => {
+const getMockClass = (pipe: Type<any>, transform?: PipeTransform['transform']): Type<any> => {
   @Pipe(coreReflectPipeResolve(pipe))
   @MockOf(pipe)
-  class PipeMock extends Mock implements PipeTransform {
+  class PipeMock extends Mock {
     public constructor(@Optional() injector?: Injector) {
       super(injector);
 
       // need to override overrides
-      if (transform !== defaultTransform) {
-        this.transform = transform;
+      if (transform) {
+        (this as any).transform = transform;
+      } else if (!(this as any).transform) {
+        helperMockService.mock(this, 'transform', `${this.constructor.name}.transform`);
       }
     }
-
-    public transform(value: any, ...args: any[]): any {
-      return transform(value, ...args);
-    }
   }
 
   return PipeMock;
@@ -50,7 +47,7 @@ export function MockPipe<TPipe extends PipeTransform>(
 
 export function MockPipe<TPipe extends PipeTransform>(
   pipe: Type<TPipe>,
-  transform: TPipe['transform'] = defaultTransform,
+  transform?: TPipe['transform'],
 ): Type<MockedPipe<TPipe>> {
   // We are inside of an 'it'. It's fine to return a mock copy.
   if ((getTestBed() as any)._instantiated) {

tests/issue-240/test.builder.spec.ts

@@ -16,18 +16,20 @@ describe('issue-240:builder', () => {
     const pure = ngMocks.findInstance(PurePipe);
     const impure = ngMocks.get(fixture.point, ImpurePipe);
 
-    spyOn(pure, 'transform');
-    spyOn(impure, 'transform');
+    // Without auto-spy we need the code below.
+    // Calls would start with 0.
+    // spyOn(pure, 'transform');
+    // spyOn(impure, 'transform');
 
-    expect(pure.transform).toHaveBeenCalledTimes(0);
-    expect(impure.transform).toHaveBeenCalledTimes(0);
-
-    fixture.detectChanges();
-    expect(pure.transform).toHaveBeenCalledTimes(0);
+    expect(pure.transform).toHaveBeenCalledTimes(1);
     expect(impure.transform).toHaveBeenCalledTimes(2);
 
     fixture.detectChanges();
-    expect(pure.transform).toHaveBeenCalledTimes(0);
+    expect(pure.transform).toHaveBeenCalledTimes(1);
     expect(impure.transform).toHaveBeenCalledTimes(4);
+
+    fixture.detectChanges();
+    expect(pure.transform).toHaveBeenCalledTimes(1);
+    expect(impure.transform).toHaveBeenCalledTimes(6);
   });
 });

tests/issue-240/test.classic.spec.ts

@@ -43,6 +43,8 @@ describe('issue-240:classic', () => {
     const pure = ngMocks.get(fixture.point, PurePipe);
     const impure = ngMocks.findInstance(ImpurePipe);
 
+    // We don't have auto-spies, because we provided callbacks.
+    // Now we need to install spies.
     spyOn(pure, 'transform');
     spyOn(impure, 'transform');
 

tests/issue-240/test.guts.spec.ts

@@ -21,18 +21,20 @@ describe('issue-240:guts', () => {
     const pure = ngMocks.get(fixture.point, PurePipe);
     const impure = ngMocks.findInstance(ImpurePipe);
 
-    spyOn(pure, 'transform');
-    spyOn(impure, 'transform');
+    // Without auto-spy we need the code below.
+    // Calls would start with 0.
+    // spyOn(pure, 'transform');
+    // spyOn(impure, 'transform');
 
-    expect(pure.transform).toHaveBeenCalledTimes(0);
-    expect(impure.transform).toHaveBeenCalledTimes(0);
-
-    fixture.detectChanges();
-    expect(pure.transform).toHaveBeenCalledTimes(0);
+    expect(pure.transform).toHaveBeenCalledTimes(1);
     expect(impure.transform).toHaveBeenCalledTimes(2);
 
     fixture.detectChanges();
-    expect(pure.transform).toHaveBeenCalledTimes(0);
+    expect(pure.transform).toHaveBeenCalledTimes(1);
     expect(impure.transform).toHaveBeenCalledTimes(4);
+
+    fixture.detectChanges();
+    expect(pure.transform).toHaveBeenCalledTimes(1);
+    expect(impure.transform).toHaveBeenCalledTimes(6);
   });
 });

tests/pipe-auto-spy/test.spec.ts

@@ -0,0 +1,22 @@
+import { Pipe, PipeTransform } from '@angular/core';
+import { MockBuilder, MockRender, ngMocks } from 'ng-mocks';
+
+@Pipe({
+  name: 'target',
+})
+class TargetPipe implements PipeTransform {
+  public transform(value: string): number {
+    return value.length;
+  }
+}
+
+describe('pipe-auto-spy', () => {
+  beforeEach(() => MockBuilder(null, TargetPipe));
+
+  it('has spy out of the box', () => {
+    MockRender(`{{ 'test' | target }}`);
+    const pipe = ngMocks.findInstance(TargetPipe);
+    expect(pipe.transform).toHaveBeenCalledWith('test');
+    expect(pipe.transform).toHaveBeenCalledTimes(1);
+  });
+});