Can't make it work using rollup.js

How are you trying to use it? Are you trying to include it in your bundle or are you trying to access it in your code as per the example?

If the latter, then once you install with

npm install --save accessible-autocomplete

You should be able to create a js file that 'imports' and uses it. E.g. test.js

import accessibleAutocomplete from 'accessible-autocomplete'

const countries = [
  'France',
  'Germany',
  'United Kingdom'
]

accessibleAutocomplete({
  element: document.querySelector('#my-autocomplete-container'),
  id: 'my-autocomplete', // To match it to the existing <label>.
  source: countries
})

'Import' here tells rollup that this (accessible-autocomplete) external dependency should be available when the js is run.

Add the js file to compile to rollup.config.js, e.g.

module.exports = [
  {
    input: 'src/javascripts/test.js',
    output: {
      file: 'application/static/javascripts/test.js',
      format: 'iife'
    }
  }
]

Then, when you run rollup it should output something like

(function (accessibleAutocomplete) {
  'use strict';

  function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }

  var accessibleAutocomplete__default = /*#__PURE__*/_interopDefaultLegacy(accessibleAutocomplete);

  const countries = [
    'France',
    'Germany',
    'United Kingdom'
  ];

  accessibleAutocomplete__default["default"]({
    element: document.querySelector('#my-autocomplete-container'),
    id: 'my-autocomplete', // To match it to the existing <label>.
    source: countries
  });

})(accessibleAutocomplete);

Expecting accessibleAutocomplete to be available globally.

Which it should be if the script has been added to the HTML file before this script. E.g.

<script src="{{ assetPath }}/accessible-autocomplete.min.js"></script>
<script src="{{ assetPath }}/test.js"></script>

If you want to include the accessible-autocomplete code in your bundle/script then I think you need to use the @rollup/plugin-node-resolve plugin.

Hope that helps.

alphagov / accessible-autocomplete

Can't make it work using rollup.js #552