Grabbed dndbeyond's source code

```
~/go/bin/sourcemapper -output ddb -jsurl https://media.dndbeyond.com/character-app/static/js/main.90aa78c5.js
```

ddb_main/hooks/useLocalStorage.ts

@@ -0,0 +1,59 @@
+import {
+  useState,
+  useEffect,
+  useCallback,
+  Dispatch,
+  SetStateAction,
+} from "react";
+
+import { tryGet, tryRemove, trySet } from "../helpers/localStorageUtils";
+
+//got most of the typing for this at https://usehooks-ts.com/react-hook/use-local-storage
+
+type SetValue<T> = Dispatch<SetStateAction<T>>;
+type RemoveValue<T> = Dispatch<SetStateAction<T>>;
+function useLocalStorage<T>(
+  key: string,
+  defaultValue: T
+): [T, SetValue<T>, RemoveValue<T>] {
+  const getValue = useCallback(() => {
+    const savedValue = tryGet(key);
+
+    return savedValue === null
+      ? (defaultValue as T)
+      : (parseJSON(savedValue) as T);
+  }, [key, defaultValue]);
+
+  const [value, setValue] = useState(getValue());
+
+  useEffect(() => {
+    setValue(getValue());
+  }, [getValue]);
+
+  const set = useCallback(
+    (newValue) => {
+      setValue(newValue);
+      trySet(key, newValue);
+    },
+    [key, setValue]
+  );
+
+  const remove = () => {
+    setValue(defaultValue as T);
+    tryRemove(key);
+  };
+
+  return [value, set, remove];
+}
+
+export default useLocalStorage;
+
+// A wrapper for "JSON.parse()"" to support "undefined" value
+function parseJSON<T>(value: any): T | undefined {
+  try {
+    return value === "undefined" ? undefined : JSON.parse(value ?? "");
+  } catch (error) {
+    console.log("parsing error on", { value });
+    return value;
+  }
+}