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', function () {
  return {
    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)
    },
  }
})