fvtt-rolemaster-frp/module/sheets/spells/rmss_spell_sheet.js

// Our Item Sheet extends the default
export default class RMSSSpellSheet extends ItemSheet {

  // Set the height and width
  static get defaultOptions() {
    return foundry.utils.mergeObject(super.defaultOptions, {
      width: 530,
      height: 440,
      classes: ["rmss", "sheet", "item"]
    });
  }

  // If our sheet is called here it is.
  get template() {
    return "systems/fvtt-rolemaster-frp/templates/sheets/spells/rmss-spell-sheet.html";
  }

  // Make the data available to the sheet template
  async getData() {
    const baseData = await super.getData();

    let enrichedDescription = await TextEditor.enrichHTML(this.item.system.description, {async: true});

    let sheetData = {
      owner: this.item.isOwner,
      editable: this.isEditable,
      item: baseData.item,
      system: baseData.item.system,
      config: CONFIG.rmss,
      enrichedDescription: enrichedDescription
    };

    return sheetData;
  }
}