@sap/cds-dk/lib/init/template/extension/index.js

Command line client and development toolkit for the SAP Cloud Application Programming Model

const cds = require('../../../cds')
const { read, write, exists, copy, path:{join, relative}, readdir, rimraf } = cds.utils
const { mkdir, symlink } = require('fs/promises')
const { renderAndCopy } = require('../../template')
const projectReader = require('../../projectReader')
const npmPackageRegex = /^(@[a-z0-9-~][a-z0-9-._~]*\/)?[a-z0-9-~][a-z0-9-._~]*$/i

module.exports = class ExtensionProjectTemplate extends require('../../plugin') {

  static help() {
    return 'Extension project'
  }

  options() {
    return {
      'base': {
        type: 'string',
        short: 'p',
        help: `The project to extend.`
      }
    }
  }


  async run() {
    let { base, force } = cds.cli.options
    if (typeof base === 'string' && !base.match(npmPackageRegex)) throw `Illegal package name: ${base}`
    if (typeof base !== 'string' || !base?.length)  base = '@capire/bookshop'

    const pkgJson = exists('package.json') ? await read('package.json') : { name: 'my-extension-project' }
    if (!pkgJson.extends || force) {
      pkgJson.extends = base
    }

    if (!pkgJson.workspaces?.includes('.base')) {
      pkgJson.workspaces ??= []
      pkgJson.workspaces.push('.base')
    }
    await write('package.json', pkgJson, { spaces: 2 })

    if (!exists('.base/package.json') || force) {
      await write('.base/package.json', {name: base})
    }

    await nodeModulesLink(base)
    // remove empty and irrelevant folders
    await Promise.all([ rmIfEmpty('db') ])
  }

  async addSample() {
    const proj = projectReader.readProject()
    const base = proj.extendsApp
    if (!base) throw 'No project to extend found in package.json. Create a new extension project with "cds init extension"'

    const projectSimple = base.replace(/^.*?\//, '')
    const extensionNamespace = `${namespacify(proj.appName)}.${namespacify(projectSimple)}`
    const { force } = cds.cli.options

    if (!exists('.base/index.cds') || force) {
      await copy(join(__dirname, 'files/.base/index.cds'), '.base/index.cds')
    }

    if (!exists('app/extension.cds') || force) {
      await renderAndCopy(join(__dirname, 'files/app'), 'app', {
        basePackage: base,
        extensionNamespace
      })
    }
    if (!exists('test/data') || force) {
      await copy(join(__dirname, 'files/test/data/my.bookshop-Books.csv'), 'test/data/my.bookshop-Books.csv')
      await copy(join(__dirname, 'files/test/data/Authors.csv'), `test/data/${extensionNamespace}-x_Authors.csv`)
    }

  }

  // async finalize() {
  //     console.log(`For information on project "Piper" and its pipelines see ${URLS.PIPELINE_HELP}`);
  // }
}

function namespacify(s) {
  return s.replace(/[/.-]/g, '_').replace(/[@]/g, '').toLowerCase()
}
async function rmIfEmpty(s) {
  exists(s) && !(await readdir(s)).length && await rimraf(s)
}

// Allow subsequent templates like `cds add handler` to resolve the model w/o `npm i`.
// So create a symlink from node_modules to .base, anticipating what `npm i` would do.
async function nodeModulesLink(base) {
  const link = join(cds.root, 'node_modules', base)
  if (exists(link))  return
  const scope = base.indexOf('/') > 0 && base.split('/')[0] // @scope/pkg
  const target = join(cds.root, 'node_modules', scope||'')
  await mkdir(target, { recursive: true })
  const relTarget = relative(target, join(cds.root, '.base'))
  // console.log(`> linking ${relTarget} to ${link}`)
  await symlink(relTarget, link, 'junction')
}