api-client/functions/editorutils.js

const mimeToMode = {
  'text/plain': 'plain_text',
  'text/html': 'html',
  'application/xml': 'xml',
  'application/hal+json': 'json',
  'application/json': 'json',
}

export function getEditorLangForMimeType(mimeType) {
  return mimeToMode[mimeType] || 'plain_text'
}