1 files changed, 39 insertions, 31 deletions

diff --git a/packages/web-util/src/hooks/useLocalStorage.ts b/packages/web-util/src/hooks/useLocalStorage.ts
index 55efd01cb..45b7abd3c 100644
--- a/packages/web-util/src/hooks/useLocalStorage.ts
+++ b/packages/web-util/src/hooks/useLocalStorage.ts
@@ -19,7 +19,7 @@
  * @author Sebastian Javier Marchano (sebasjm)
  */
 
-import { Codec } from "@gnu-taler/taler-util";
+import { Codec, codecForString } from "@gnu-taler/taler-util";
 import { useEffect, useState } from "preact/hooks";
 import {
   ObservableMap,
@@ -28,7 +28,26 @@ import {
   memoryMap,
 } from "../utils/observable.js";
 
-export interface LocalStorageState<Type = string> {
+declare const opaque_StorageKey: unique symbol;
+
+export type StorageKey<Key> = {
+  id: string;
+  [opaque_StorageKey]: true;
+  codec: Codec<Key>;
+};
+
+export function buildStorageKey<Key = string>(
+  name: string,
+  codec?: Codec<Key>,
+): StorageKey<Key> {
+  return {
+    id: name,
+    codec: codec ?? (codecForString() as Codec<Key>),
+    [opaque_StorageKey]: true,
+  };
+}
+
+export interface StorageState<Type = string> {
   value?: Type;
   update: (s: Type) => void;
   reset: () => void;
@@ -50,59 +69,48 @@ const storage: ObservableMap<string, string> = (function buildStorage() {
 
 //with initial value
 export function useLocalStorage<Type = string>(
-  key: string,
-  options?: {
-    defaultValue: Type;
-    codec?: Codec<Type>;
-  },
-): Required<LocalStorageState<Type>>;
+  key: StorageKey<Type>,
+  defaultValue: Type,
+): Required<StorageState<Type>>;
 //without initial value
 export function useLocalStorage<Type = string>(
-  key: string,
-  options?: {
-    codec?: Codec<Type>;
-  },
-): LocalStorageState<Type>;
+  key: StorageKey<Type>,
+): StorageState<Type>;
 // impl
 export function useLocalStorage<Type = string>(
-  key: string,
-  options?: {
-    defaultValue?: Type;
-    codec?: Codec<Type>;
-  },
-): LocalStorageState<Type> {
+  key: StorageKey<Type>,
+  defaultValue?: Type,
+): StorageState<Type> {
   function convert(updated: string | undefined): Type | undefined {
-    if (updated === undefined) return options?.defaultValue; //optional
+    if (updated === undefined) return defaultValue; //optional
     try {
-      return !options?.codec
-        ? (updated as Type)
-        : options.codec.decode(JSON.parse(updated));
+      return key.codec.decode(JSON.parse(updated));
     } catch (e) {
       //decode error
-      return options?.defaultValue;
+      return defaultValue;
     }
   }
   const [storedValue, setStoredValue] = useState<Type | undefined>(
     (): Type | undefined => {
-      const prev = storage.get(key);
+      const prev = storage.get(key.id);
       return convert(prev);
     },
   );
 
   useEffect(() => {
-    return storage.onUpdate(key, () => {
-      const newValue = storage.get(key);
+    return storage.onUpdate(key.id, () => {
+      const newValue = storage.get(key.id);
       setStoredValue(convert(newValue));
     });
   }, []);
 
   const setValue = (value?: Type): void => {
     if (value === undefined) {
-      storage.delete(key);
+      storage.delete(key.id);
     } else {
       storage.set(
-        key,
-        options?.codec ? JSON.stringify(value) : (value as string),
+        key.id,
+        key.codec ? JSON.stringify(value) : (value as string),
       );
     }
   };
@@ -111,7 +119,7 @@ export function useLocalStorage<Type = string>(
     value: storedValue,
     update: setValue,
     reset: () => {
-      setValue(options?.defaultValue);
+      setValue(defaultValue);
     },
   };
 }