Convert to typescript

src/App.tsx

@@ -0,0 +1,77 @@
+import { useCallback, useEffect, useState } from 'react';
+import Editor from './components/Editor';
+import { loadFromBytebin } from './util/storage';
+
+const INITIAL = Symbol();
+const LOADING = Symbol();
+const LOADED = Symbol();
+
+type LoadingState = typeof INITIAL | typeof LOADING | typeof LOADED;
+
+export default function App() {
+  const [pasteId] = useState<string | undefined>(getPasteIdFromUrl);
+  const [state, setState] = useState<LoadingState>(INITIAL);
+  const [forcedContent, setForcedContent] = useState<string>('');
+  const [actualContent, setActualContent] = useState<string>('');
+  const [contentType, setContentType] = useState<string>();
+
+  const setContent = useCallback(
+    (content: string) => {
+      setActualContent(content);
+      setForcedContent(content);
+    },
+    [setActualContent, setForcedContent]
+  );
+
+  useEffect(() => {
+    if (pasteId && state === INITIAL) {
+      setState(LOADING);
+      setForcedContent('Loading...');
+      loadFromBytebin(pasteId).then(({ ok, content, type }) => {
+        if (ok) {
+          setContent(content);
+          if (type) {
+            setContentType(type);
+          }
+        } else {
+          setContent(get404Message(pasteId));
+        }
+        setState(LOADED);
+      });
+    }
+  }, [pasteId, state, setContent]);
+
+  return (
+    <Editor
+      forcedContent={forcedContent}
+      setForcedContent={setContent}
+      actualContent={actualContent}
+      setActualContent={setActualContent}
+      contentType={contentType}
+      pasteId={pasteId}
+    />
+  );
+}
+
+function get404Message(pasteId: string) {
+  return `
+  ██╗  ██╗ ██████╗ ██╗  ██╗
+  ██║  ██║██╔═████╗██║  ██║
+  ███████║██║██╔██║███████║
+  ╚════██║████╔╝██║╚════██║
+       ██║╚██████╔╝     ██║
+       ╚═╝ ╚═════╝      ╚═╝
+
+  not found: '${pasteId}'
+  maybe the paste expired?
+`;
+}
+
+function getPasteIdFromUrl() {
+  const path = window.location.pathname;
+  if (path && /^\/[a-zA-Z0-9]+$/.test(path)) {
+    return path.substring(1);
+  } else {
+    return undefined;
+  }
+}