@nuxtjs/mdc/dist/runtime/parser/handlers/emphasis.js

Nuxt MDC module

export default function emphasis(state, node) {
  const result = {
    type: "element",
    tagName: "em",
    properties: node.attributes || {},
    children: state.all(node)
  };
  state.patch(node, result);
  return state.applyData(node, result);
}