[Drupal 8.6.x] #states breaks when OR is used

Problem/Motivation

[Drupal 8.6.x] #states breaks when OR is used.

The below YAML code…

select:
  '#type': select
  '#title': select
  '#options':
    1: 1
    2: 2
number:
  '#type': number
  '#title': number
textfield:
  '#type': textfield
  '#title': textfield
  '#states':
    visible:
      - ':input[name="select"]':
          value: 1
      - or
      - ':input[name="number"]':
          value: 1

or PHP code (which can be added to any form)…

  $form['select'] = [
    '#type' =>'select',
    '#title' => 'select 1',
    '#options' => [0 => 0, 1 => 1, 2 => 2],
  ];
  $form['number'] = [
    '#type' => 'number',
    '#title' => 'enter 1',
  ];
  $form['textfield'] = [
    '#type' => 'textfield',
    '#title' => 'textfield',
    '#states' => [
      'visible' => [
        [':input[name="select"]' => ['value' => '1']],
        'or',
        [':input[name="number"]' => ['value' => '1']],
      ],
    ],
  ];

Logs the below exception…

This issue is being triggered by #2981652: [Aug. 9 2018] Format core JavaScript using recently add Prettier.

Proposed resolution

TBD

Remaining tasks

TBD

User interface changes

N/A

API changes

N/A

Data model changes

N/A