test(ivy): implement tests for template type-checking (#26203)

This commit builds on the NgtscTestEnvironment helper work before and
introduces template_typecheck_spec.ts, which contains compiler tests
for template type-checking.

PR Close #26203

packages/compiler-cli/test/ngtsc/fake_core/index.ts

@@ -39,6 +39,8 @@ export const ContentChild = callablePropDecorator();
 export const ContentChildren = callablePropDecorator();
 export const HostBinding = callablePropDecorator();
 export const HostListener = callablePropDecorator();
+export const Input = callablePropDecorator();
+export const Output = callablePropDecorator();
 export const ViewChild = callablePropDecorator();
 export const ViewChildren = callablePropDecorator();
 

packages/compiler-cli/test/ngtsc/template_typecheck_spec.ts

@@ -0,0 +1,172 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {NgtscTestEnvironment} from './env';
+
+function setupCommon(env: NgtscTestEnvironment): void {
+  env.write('node_modules/@angular/common/index.d.ts', `
+import * as i0 from '@angular/core';
+
+export declare class NgForOfContext<T> {
+  $implicit: T;
+  ngForOf: T[];
+  index: number;
+  count: number;
+  readonly first: boolean;
+  readonly last: boolean;
+  readonly even: boolean;
+  readonly odd: boolean;
+}
+
+export declare class NgForOf<T> {
+  ngForOf: T[];
+  static ngTemplateContextGuard<T>(dir: NgForOf<T>, ctx: any): ctx is NgForOfContext<T>;
+  static ngDirectiveDef: i0.ɵDirectiveDefWithMeta<NgForOf<any>, '[ngFor][ngForOf]', never, {'ngForOf': 'ngForOf'}, {}, never>;
+}
+
+export declare class NgIf {
+  ngIf: any;
+  static ngTemplateGuard_ngIf<E>(dir: NgIf, expr: E): expr is NonNullable<E>
+  static ngDirectiveDef: i0.ɵDirectiveDefWithMeta<NgForOf<any>, '[ngIf]', never, {'ngIf': 'ngIf'}, {}, never>;
+}
+
+export declare class CommonModule {
+  static ngModuleDef: i0.ɵNgModuleDefWithMeta<CommonModule, [typeof NgIf, typeof NgForOf], never, [typeof NgIf, typeof NgForOf]>;
+}
+`);
+}
+
+describe('ngtsc type checking', () => {
+  if (!NgtscTestEnvironment.supported) {
+    // These tests should be excluded from the non-Bazel build.
+    return;
+  }
+
+  let env !: NgtscTestEnvironment;
+
+  beforeEach(() => {
+    env = NgtscTestEnvironment.setup();
+    env.tsconfig({fullTemplateTypeCheck: true});
+    setupCommon(env);
+  });
+
+  it('should check a simple component', () => {
+    env.write('test.ts', `
+    import {Component, NgModule} from '@angular/core';
+
+    @Component({
+      selector: 'test',
+      template: 'I am a simple template with no type info',
+    })
+    class TestCmp {}
+
+    @NgModule({
+      declarations: [TestCmp],
+    })
+    class Module {}
+    `);
+
+    env.driveMain();
+  });
+
+  it('should check basic usage of NgIf', () => {
+    env.write('test.ts', `
+    import {CommonModule} from '@angular/common';
+    import {Component, NgModule} from '@angular/core';
+
+    @Component({
+      selector: 'test',
+      template: '<div *ngIf="user">{{user.name}}</div>',
+    })
+    class TestCmp {
+      user: {name: string}|null;
+    }
+
+    @NgModule({
+      declarations: [TestCmp],
+      imports: [CommonModule],
+    })
+    class Module {}
+    `);
+
+    env.driveMain();
+  });
+
+  it('should check basic usage of NgFor', () => {
+    env.write('test.ts', `
+    import {CommonModule} from '@angular/common';
+    import {Component, NgModule} from '@angular/core';
+
+    @Component({
+      selector: 'test',
+      template: '<div *ngFor="let user of users">{{user.name}}</div>',
+    })
+    class TestCmp {
+      users: {name: string}[];
+    }
+
+    @NgModule({
+      declarations: [TestCmp],
+      imports: [CommonModule],
+    })
+    class Module {}
+    `);
+
+    env.driveMain();
+  });
+
+  it('should report an error inside the NgFor template', () => {
+    env.write('test.ts', `
+    import {CommonModule} from '@angular/common';
+    import {Component, NgModule} from '@angular/core';
+
+    @Component({
+      selector: 'test',
+      template: '<div *ngFor="let user of users">{{user.does_not_exist}}</div>',
+    })
+    class TestCmp {
+      users: {name: string}[];
+    }
+
+    @NgModule({
+      declarations: [TestCmp],
+      imports: [CommonModule],
+    })
+    class Module {}
+    `);
+
+    const diags = env.driveDiagnostics();
+    expect(diags.length).toBe(1);
+    expect(diags[0].messageText).toContain('does_not_exist');
+  });
+
+  it('should constrain types using type parameter bounds', () => {
+    env.write('test.ts', `
+    import {CommonModule} from '@angular/common';
+    import {Component, Input, NgModule} from '@angular/core';
+
+    @Component({
+      selector: 'test',
+      template: '<div *ngFor="let user of users">{{user.does_not_exist}}</div>',
+    })
+    class TestCmp<T extends {name: string}> {
+      @Input() users: T[];
+    }
+
+    @NgModule({
+      declarations: [TestCmp],
+      imports: [CommonModule],
+    })
+    class Module {}
+    `);
+
+    const diags = env.driveDiagnostics();
+    expect(diags.length).toBe(1);
+    expect(diags[0].messageText).toContain('does_not_exist');
+  });
+});