Simple rollup plugin to automatically add an import line

rollup-plugin-add-import.js

import { createFilter } from 'rollup-pluginutils'

function assign (target, source) {
  Object.keys(source).forEach((key) => {
    target[key] = source[key]
  })
  return target
}

const DEFAULT_HEADER = 'import React from \'react\';'

export default (opts) => {
  opts = assign({}, opts || {})
  if (!opts.include) {
    throw Error('include option should be specified')
  }
  let filter = createFilter(opts.include, opts.exclude)
  let header = opts.header !== undefined ? opts.header : DEFAULT_HEADER

  return {
    name: 'add-import',

    transform (code, id) {
      if (!filter(id)) return
      return {
        code: header + '\n' + code,
        map: { mappings: '' }
      }
    }
  }
}

though I was only one in the universe, who is thinking about this .. thanks .. 🤟