adjust-default-dev-port.ts

import { getWorkspaceLayout, names, Tree, updateJson } from '@nrwl/devkit'

// ...

function adjustDefaultDevPort(tree: Tree, options: AppGeneratorSchema) {
  const { fileName } = names(options.name);
  updateJson(tree, `apps/${fileName}-web/project.json`, (json) => ({
    ...json,
    targets: {
      ...json.targets,
      serve: {
        ...json.targets.serve,
        options: {
          ...json.targets.serve.options,
          port: options.frontendPort,
        },
      },
    },
  }));
}