feat(@schematics/angular): add option to export component as default

Introduces option `--export-default` to control whether the generated component uses a default export instead of a named export.

Closes: #25023

packages/schematics/angular/component/files/__name@dasherize@if-flat__/__name@dasherize__.__type@dasherize__.ts.template

@@ -19,6 +19,6 @@ import { <% if(changeDetection !== 'Default') { %>ChangeDetectionStrategy, <% }%
   encapsulation: ViewEncapsulation.<%= viewEncapsulation %><% } if (changeDetection !== 'Default') { %>,
   changeDetection: ChangeDetectionStrategy.<%= changeDetection %><% } %>
 })
-export class <%= classify(name) %><%= classify(type) %> {
+export <% if(exportDefault) {%>default <%}%>class <%= classify(name) %><%= classify(type) %> {
 
 }

packages/schematics/angular/component/index_spec.ts

@@ -496,4 +496,20 @@ describe('Component Schematic', () => {
       await expectAsync(schematicRunner.runSchematic('component', options, appTree)).toBeRejected();
     });
   });
+
+  it('should export the component as default when exportDefault is true', async () => {
+    const options = { ...defaultOptions, exportDefault: true };
+
+    const tree = await schematicRunner.runSchematic('component', options, appTree);
+    const tsContent = tree.readContent('/projects/bar/src/app/foo/foo.component.ts');
+    expect(tsContent).toContain('export default class FooComponent');
+  });
+
+  it('should export the component as a named export when exportDefault is false', async () => {
+    const options = { ...defaultOptions, exportDefault: false };
+
+    const tree = await schematicRunner.runSchematic('component', options, appTree);
+    const tsContent = tree.readContent('/projects/bar/src/app/foo/foo.component.ts');
+    expect(tsContent).toContain('export class FooComponent');
+  });
 });

packages/schematics/angular/component/schema.json

@@ -130,6 +130,11 @@
       "type": "boolean",
       "default": false,
       "description": "The declaring NgModule exports this component."
+    },
+    "exportDefault": {
+      "type": "boolean",
+      "default": false,
+      "description": "Use default export for the component instead of a named export."
     }
   },
   "required": ["name", "project"]