overleaf/services/web/frontend/js/directives/expandableTextArea.js

// TODO: This file was created by bulk-decaffeinate.
// Fix any style issues and re-enable lint.
/*
 * decaffeinate suggestions:
 * DS102: Remove unnecessary code created because of implicit returns
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
 */
import App from '../base'

export default App.directive('expandableTextArea', () => ({
  restrict: 'A',
  link(scope, el) {
    const resetHeight = function () {
      const curHeight = el.outerHeight()
      const fitHeight = el.prop('scrollHeight')
      // clear height if text area is empty
      if (el.val() === '') {
        el.css('height', 'unset')
      }
      // otherwise expand to fit text
      else if (fitHeight > curHeight) {
        scope.$emit('expandable-text-area:resize')
        el.css('height', fitHeight)
      }
    }

    return scope.$watch(() => el.val(), resetHeight)
  },
}))