fix(material/schematics): support standalone projects in tree schematic

Updates the `ng generate tree` schematic to support standalone projects.

Author: crisbeto

src/material/schematics/ng-generate/tree/files/__path__/__name@dasherize@if-flat__/__name@dasherize__.component.spec.ts.template

@@ -1,24 +1,24 @@
-import { waitForAsync, ComponentFixture, TestBed } from '@angular/core/testing';
+import { <% if(!standalone) { %>waitForAsync, <% } %>ComponentFixture, TestBed } from '@angular/core/testing';<% if(!standalone) { %>
 import { MatButtonModule } from '@angular/material/button';
 import { MatIconModule } from '@angular/material/icon';
-import { MatTreeModule } from '@angular/material/tree';
+import { MatTreeModule } from '@angular/material/tree';<% } %>
 
 import { <%= classify(name) %>Component } from './<%= dasherize(name) %>.component';
 
 describe('<%= classify(name) %>Component', () => {
   let component: <%= classify(name) %>Component;
-  let fixture: ComponentFixture<<%= classify(name) %>Component>;
+  let fixture: ComponentFixture<<%= classify(name) %>Component>;<% if(!standalone) { %>
 
   beforeEach(waitForAsync(() => {
     TestBed.configureTestingModule({
-      declarations: [ <%= classify(name) %>Component ],
+      declarations: [<%= classify(name) %>Component],
       imports: [
         MatButtonModule,
         MatIconModule,
         MatTreeModule,
       ]
     }).compileComponents();
-  }));
+  }));<% } %>
 
   beforeEach(() => {
     fixture = TestBed.createComponent(<%= classify(name) %>Component);

src/material/schematics/ng-generate/tree/files/__path__/__name@dasherize@if-flat__/__name@dasherize__.component.ts.template

@@ -1,6 +1,8 @@
 import { Component<% if (!!viewEncapsulation) { %>, ViewEncapsulation<% }%><% if (changeDetection !== 'Default') { %>, ChangeDetectionStrategy<% }%> } from '@angular/core';
-import { MatTreeFlatDataSource, MatTreeFlattener } from '@angular/material/tree';
-import { FlatTreeControl } from '@angular/cdk/tree';
+import { <% if(standalone) { %>MatTreeModule, <% } %>MatTreeFlatDataSource, MatTreeFlattener } from '@angular/material/tree';
+import { FlatTreeControl } from '@angular/cdk/tree';<% if(standalone) { %>
+import { MatButtonModule } from '@angular/material/button';
+import { MatIconModule } from '@angular/material/icon';<% } %>
 import { files } from './example-data';
 
 /** File node data with possible child nodes. */
@@ -32,7 +34,9 @@ export interface FlatTreeNode {
   `]<% } else { %>
   styleUrls: ['./<%= dasherize(name) %>.component.<%= style %>']<% } %><% if(!!viewEncapsulation) { %>,
   encapsulation: ViewEncapsulation.<%= viewEncapsulation %><% } if (changeDetection !== 'Default') { %>,
-  changeDetection: ChangeDetectionStrategy.<%= changeDetection %><% } %>
+  changeDetection: ChangeDetectionStrategy.<%= changeDetection %><% } %><% if(standalone) { %>,
+  standalone: true,
+  imports: [MatTreeModule, MatButtonModule, MatIconModule]<% } %>
 })
 export class <%= classify(name) %>Component {
 

src/material/schematics/ng-generate/tree/index.spec.ts

@@ -48,6 +48,38 @@ describe('Material tree schematic', () => {
     ).toBeRejectedWithError(/required property 'name'/);
   });
 
+  describe('standalone option', () => {
+    it('should generate a standalone component', async () => {
+      const app = await createTestApp(runner);
+      const tree = await runner.runSchematic('tree', {...baseOptions, standalone: true}, app);
+      const module = getFileContent(tree, '/projects/material/src/app/app.module.ts');
+      const component = getFileContent(tree, '/projects/material/src/app/foo/foo.component.ts');
+      const requiredModules = ['MatTreeModule', 'MatButtonModule', 'MatIconModule'];
+
+      requiredModules.forEach(name => {
+        expect(module).withContext('Module should not import dependencies').not.toContain(name);
+        expect(component).withContext('Component should import dependencies').toContain(name);
+      });
+
+      expect(module).not.toContain('FooComponent');
+      expect(component).toContain('standalone: true');
+      expect(component).toContain('imports: [');
+    });
+
+    it('should infer the standalone option from the project structure', async () => {
+      const app = await createTestApp(runner, {standalone: true});
+      const tree = await runner.runSchematic('tree', baseOptions, app);
+      const componentContent = getFileContent(
+        tree,
+        '/projects/material/src/app/foo/foo.component.ts',
+      );
+
+      expect(tree.exists('/projects/material/src/app/app.module.ts')).toBe(false);
+      expect(componentContent).toContain('standalone: true');
+      expect(componentContent).toContain('imports: [');
+    });
+  });
+
   describe('style option', () => {
     it('should respect the option value', async () => {
       const tree = await runner.runSchematic(

src/material/schematics/ng-generate/tree/index.ts

@@ -11,6 +11,7 @@ import {
   addModuleImportToModule,
   buildComponent,
   findModuleFromOptions,
+  isStandaloneSchematic,
 } from '@angular/cdk/schematics';
 import {Schema} from './schema';
 
@@ -38,9 +39,13 @@ export default function (options: Schema): Rule {
  */
 function addTreeModulesToModule(options: Schema) {
   return async (host: Tree) => {
-    const modulePath = (await findModuleFromOptions(host, options))!;
-    addModuleImportToModule(host, modulePath, 'MatTreeModule', '@angular/material/tree');
-    addModuleImportToModule(host, modulePath, 'MatIconModule', '@angular/material/icon');
-    addModuleImportToModule(host, modulePath, 'MatButtonModule', '@angular/material/button');
+    const isStandalone = await isStandaloneSchematic(host, options);
+
+    if (!isStandalone) {
+      const modulePath = (await findModuleFromOptions(host, options))!;
+      addModuleImportToModule(host, modulePath, 'MatTreeModule', '@angular/material/tree');
+      addModuleImportToModule(host, modulePath, 'MatIconModule', '@angular/material/icon');
+      addModuleImportToModule(host, modulePath, 'MatButtonModule', '@angular/material/button');
+    }
   };
 }

src/material/schematics/ng-generate/tree/schema.json

@@ -39,6 +39,10 @@
       "type": "boolean",
       "alias": "t"
     },
+    "standalone": {
+      "description": "Whether the generated component is standalone.",
+      "type": "boolean"
+    },
     "viewEncapsulation": {
       "description": "Specifies the view encapsulation strategy.",
       "enum": ["Emulated", "None"],