From 2f5fd41a1987509fc0250c1441554984b6e11abc Mon Sep 17 00:00:00 2001
From: Pawel Kozlowski <pkozlowski.opensource@gmail.com>
Date: Wed, 27 Apr 2022 13:24:35 +0200
Subject: [PATCH] refactor(core): verify that standalone entities are not
 declared in NgModule (#45777)

This commits adds JiT checks to verify that a standalone component, directive,
pipe are not declared in any NgModule.

PR Close #45777
---
 packages/core/src/render3/jit/module.ts       | 14 ++-
 .../core/test/acceptance/ng_module_spec.ts    | 88 ++++++++++++++++++-
 2 files changed, 100 insertions(+), 2 deletions(-)

diff --git a/packages/core/src/render3/jit/module.ts b/packages/core/src/render3/jit/module.ts
index f039b5d89eaa2..a1a46e67146ae 100644
--- a/packages/core/src/render3/jit/module.ts
+++ b/packages/core/src/render3/jit/module.ts
@@ -207,7 +207,7 @@ function verifySemanticsOfNgModuleDef(
     importingModule?: NgModuleType): void {
   if (verifiedNgModule.get(moduleType)) return;
 
-  // skip verifications of standalone components, direcrtives and pipes
+  // skip verifications of standalone components, directives and pipes
   if (isStandalone(moduleType)) return;
 
   verifiedNgModule.set(moduleType, true);
@@ -232,6 +232,7 @@ function verifySemanticsOfNgModuleDef(
   const exports = maybeUnwrapFn(ngModuleDef.exports);
   declarations.forEach(verifyDeclarationsHaveDefinitions);
   declarations.forEach(verifyDirectivesHaveSelector);
+  declarations.forEach((declarationType) => verifyNotStandalone(declarationType, moduleType));
   const combinedDeclarations: Type<any>[] = [
     ...declarations.map(resolveForwardRef),
     ...flatten(imports.map(computeCombinedExports)).map(resolveForwardRef),
@@ -275,6 +276,17 @@ function verifySemanticsOfNgModuleDef(
     }
   }
 
+  function verifyNotStandalone(type: Type<any>, moduleType: NgModuleType): void {
+    type = resolveForwardRef(type);
+    const def = getComponentDef(type) || getDirectiveDef(type) || getPipeDef(type);
+    if (def?.standalone) {
+      errors.push(`Unexpected "${stringifyForError(type)}" declaration in "${
+          stringifyForError(moduleType)}" NgModule. "${
+          stringifyForError(
+              type)}" is marked as standalone and can't be declared in any NgModule - did you intend to import it?`);
+    }
+  }
+
   function verifyExportsAreDeclaredOrReExported(type: Type<any>) {
     type = resolveForwardRef(type);
     const kind = getComponentDef(type) && 'component' || getDirectiveDef(type) && 'directive' ||
diff --git a/packages/core/test/acceptance/ng_module_spec.ts b/packages/core/test/acceptance/ng_module_spec.ts
index db111d7c8a9a5..ad2f3bbca7b35 100644
--- a/packages/core/test/acceptance/ng_module_spec.ts
+++ b/packages/core/test/acceptance/ng_module_spec.ts
@@ -7,7 +7,7 @@
  */
 
 import {CommonModule} from '@angular/common';
-import {Component, createNgModuleRef, CUSTOM_ELEMENTS_SCHEMA, destroyPlatform, Injectable, InjectionToken, NgModule, NgModuleRef, NO_ERRORS_SCHEMA, ɵsetClassMetadata as setClassMetadata, ɵɵdefineComponent as defineComponent, ɵɵdefineInjector as defineInjector, ɵɵdefineNgModule as defineNgModule, ɵɵelement as element, ɵɵproperty as property} from '@angular/core';
+import {Component, createNgModuleRef, CUSTOM_ELEMENTS_SCHEMA, destroyPlatform, Directive, Injectable, InjectionToken, NgModule, NgModuleRef, NO_ERRORS_SCHEMA, Pipe, ɵsetClassMetadata as setClassMetadata, ɵɵdefineComponent as defineComponent, ɵɵdefineInjector as defineInjector, ɵɵdefineNgModule as defineNgModule, ɵɵelement as element, ɵɵproperty as property} from '@angular/core';
 import {TestBed} from '@angular/core/testing';
 import {BrowserModule} from '@angular/platform-browser';
 import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
@@ -102,6 +102,92 @@ describe('NgModule', () => {
     expect(TestBed.inject(Service).initializations).toEqual(['RoutesModule', 'AppModule']);
   });
 
+  describe('standalone components, directives and pipes', () => {
+    it('should throw when a standalone component is added to NgModule declarations', () => {
+      @Component({
+        selector: 'my-comp',
+        standalone: true,
+        template: '',
+      })
+      class MyComp {
+      }
+
+      @NgModule({
+        declarations: [MyComp],
+      })
+      class MyModule {
+      }
+
+      TestBed.configureTestingModule({imports: [MyModule]});
+
+      expect(() => {
+        TestBed.createComponent(MyComp);
+      })
+          .toThrowError(
+              `Unexpected "MyComp" declaration in "MyModule" NgModule. "MyComp" is marked as standalone and can't be declared in any NgModule - did you intend to import it?`);
+    });
+
+    it('should throw when a standalone directive is added to NgModule declarations', () => {
+      @Directive({
+        selector: '[my-dir]',
+        standalone: true,
+      })
+      class MyDir {
+      }
+
+      @Component({
+        selector: 'my-comp',
+        template: '',
+      })
+      class MyComp {
+      }
+
+      @NgModule({
+        declarations: [MyDir],
+      })
+      class MyModule {
+      }
+
+      TestBed.configureTestingModule({declarations: [MyComp], imports: [MyModule]});
+
+      expect(() => {
+        TestBed.createComponent(MyComp);
+      })
+          .toThrowError(
+              `Unexpected "MyDir" declaration in "MyModule" NgModule. "MyDir" is marked as standalone and can't be declared in any NgModule - did you intend to import it?`);
+    });
+
+    it('should throw when a standalone pipe is added to NgModule declarations', () => {
+      @Pipe({
+        name: 'my-pipe',
+        standalone: true,
+      })
+      class MyPipe {
+      }
+
+      @Component({
+        selector: 'my-comp',
+        template: '',
+      })
+      class MyComp {
+      }
+
+      @NgModule({
+        declarations: [MyPipe],
+      })
+      class MyModule {
+      }
+
+      TestBed.configureTestingModule({declarations: [MyComp], imports: [MyModule]});
+
+      expect(() => {
+        TestBed.createComponent(MyComp);
+      })
+          .toThrowError(
+              `Unexpected "MyPipe" declaration in "MyModule" NgModule. "MyPipe" is marked as standalone and can't be declared in any NgModule - did you intend to import it?`);
+    });
+  });
+
   describe('destroy', () => {
     beforeEach(destroyPlatform);
     afterEach(destroyPlatform);