storybook/lib/cli/generators/SVELTE/index.js

import path from 'path';
import mergeDirs from 'merge-dirs';
import { getVersions, getPackageJson, writePackageJson, installBabel } from '../../lib/helpers';

export default async npmOptions => {
  const [
    storybookVersion,
    actionsVersion,
    linksVersion,
    addonsVersion,
    svelte,
    svelteLoader,
  ] = await getVersions(
    npmOptions,
    '@storybook/svelte',
    '@storybook/addon-actions',
    '@storybook/addon-links',
    '@storybook/addons',
    'svelte',
    'svelte-loader'
  );

  mergeDirs(path.resolve(__dirname, 'template/'), '.', 'overwrite');

  const packageJson = getPackageJson();

  packageJson.dependencies = packageJson.dependencies || {};
  packageJson.devDependencies = packageJson.devDependencies || {};
  packageJson.devDependencies['@storybook/svelte'] = storybookVersion;
  packageJson.devDependencies['@storybook/addon-actions'] = actionsVersion;
  packageJson.devDependencies['@storybook/addon-links'] = linksVersion;
  packageJson.devDependencies['@storybook/addons'] = addonsVersion;
  packageJson.devDependencies.svelte = svelte;
  packageJson.devDependencies['svelte-loader'] = svelteLoader;

  await installBabel(npmOptions, packageJson);

  packageJson.scripts = packageJson.scripts || {};
  packageJson.scripts.storybook = 'start-storybook -p 6006';
  packageJson.scripts['build-storybook'] = 'build-storybook';

  writePackageJson(packageJson);
};