message: implement url string property for `patch`
diff: @@ -41,7 +41,7 @@ export interface EmbedOptions {
  loader?: Loader | LoaderOptions;
  renderer?: Renderers;
  tooltip?: TooltipHandler | TooltipOptions | boolean;
  - patch?: PatchFunc | DeepPartial<VgSpec>;
  + patch?: string | PatchFunc | DeepPartial<VgSpec>;
  onBeforeParse?: PatchFunc; // for backwards compatibility
  width?: number;
  height?: number;
  @@ -244,6 +244,9 @@ export default async function embed(
  if (patch) {
  if (patch instanceof Function) {
  vgSpec = patch(vgSpec);
  + } else if (vega.isString(patch)) {
  + const patchString = await loader.load(patch);
  + vgSpec = mergeDeep(vgSpec, JSON.parse(patchString));
  } else {
  vgSpec = mergeDeep(vgSpec, patch);
  }
  