Use async/await for async functions.

src/load_data.ts

@@ -32,37 +32,32 @@ function prepareData(
 }
 
 /** Fetches data from the given URL. Uses cors-anywhere if handleCors is true. */
-export function loadFromUrl(
+export async function loadFromUrl(
   url: string,
   handleCors: boolean,
 ): Promise<TopolaData> {
   const cachedData = sessionStorage.getItem(url);
   if (cachedData) {
-    return Promise.resolve(JSON.parse(cachedData));
+    return JSON.parse(cachedData);
   }
   const urlToFetch = handleCors
     ? 'https://cors-anywhere.herokuapp.com/' + url
     : url;
 
-  return window
-    .fetch(urlToFetch)
-    .then((response) => {
-      if (response.status !== 200) {
-        return Promise.reject(new Error(response.statusText));
-      }
-      return response.text();
-    })
-    .then((gedcom) => {
-      return prepareData(gedcom, url);
-    });
+  const response = await window.fetch(urlToFetch);
+  if (response.status !== 200) {
+    throw new Error(response.statusText);
+  }
+  const gedcom = await response.text();
+  return prepareData(gedcom, url);
 }
 
 /** Loads data from the given GEDCOM file contents. */
-function loadGedcomSync(
+export async function loadGedcom(
   hash: string,
   gedcom?: string,
   images?: Map<string, string>,
-) {
+): Promise<TopolaData> {
   const cachedData = sessionStorage.getItem(hash);
   if (cachedData) {
     return JSON.parse(cachedData);
@@ -72,16 +67,3 @@ function loadGedcomSync(
   }
   return prepareData(gedcom, hash, images);
 }
-
-/** Loads data from the given GEDCOM file contents. */
-export function loadGedcom(
-  hash: string,
-  gedcom?: string,
-  images?: Map<string, string>,
-): Promise<TopolaData> {
-  try {
-    return Promise.resolve(loadGedcomSync(hash, gedcom, images));
-  } catch (e) {
-    return Promise.reject(new Error('Failed to read GEDCOM file'));
-  }
-}