index.ts

import { Rule, SchematicContext, Tree, chain, externalSchematic } from '@angular-devkit/schematics';

const licenseText = `
/**
 * @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
 */
`;

export function myComponent(options: any): Rule {
  return chain([
    externalSchematic('@schematics/angular', 'component', options),
    (tree: Tree, _context: SchematicContext) => {
      tree.getDir(options.sourceDir)
          .visit(filePath => {
            if (!filePath.endsWith('.ts')) {
              return;
            }
            const content = tree.read(filePath);
            if (!content) {
              return;
            }

            // Prevent from writing license to files that already have one.
            if (content.indexOf(licenseText) == -1) {
              tree.overwrite(filePath, licenseText + content);
            }
          });
      return tree;
    },
  ]);
}