refactor(hooks): rewrite useLocalStorage hook

* return a tuple instead of an object
* add a validator function as parameter (if the stored value
is manually changed, it is not safe to cast its type)
* add tests

4 files changed, 98 insertions, 33 deletions

diff --git a/src/utils/hooks/use-local-storage.tsx b/src/utils/hooks/use-local-storage.tsx
deleted file mode 100644
index 0f9fbb6..0000000
--- a/src/utils/hooks/use-local-storage.tsx
+++ /dev/null
@@ -1,33 +0,0 @@
-import { LocalStorage } from '../../services/local-storage';
-import { Dispatch, SetStateAction, useEffect, useState } from 'react';
-
-export type UseLocalStorageReturn<T> = {
-  value: T;
-  setValue: Dispatch<SetStateAction<T>>;
-};
-
-/**
- * Use the local storage.
- *
- * @param {string} key - The storage local key.
- * @param {T} [fallbackValue] - A fallback value if local storage is empty.
- * @returns {UseLocalStorageReturn<T>} An object with value and setValue.
- */
-export const useLocalStorage = <T,>(
-  key: string,
-  fallbackValue: T
-): UseLocalStorageReturn<T> => {
-  const getInitialValue = () => {
-    if (typeof window === 'undefined') return fallbackValue;
-    const storedValue = LocalStorage.get<T>(key);
-    return storedValue ?? fallbackValue;
-  };
-
-  const [value, setValue] = useState<T>(getInitialValue);
-
-  useEffect(() => {
-    LocalStorage.set(key, value);
-  }, [key, value]);
-
-  return { value, setValue };
-};
diff --git a/src/utils/hooks/use-local-storage/index.ts b/src/utils/hooks/use-local-storage/index.ts
new file mode 100644
index 0000000..87c1953
--- /dev/null
+++ b/src/utils/hooks/use-local-storage/index.ts
@@ -0,0 +1 @@
+export * from './use-local-storage';
diff --git a/src/utils/hooks/use-local-storage/use-local-storage.test.ts b/src/utils/hooks/use-local-storage/use-local-storage.test.ts
new file mode 100644
index 0000000..3b63495
--- /dev/null
+++ b/src/utils/hooks/use-local-storage/use-local-storage.test.ts
@@ -0,0 +1,59 @@
+import { describe, expect, it } from '@jest/globals';
+import { act, renderHook } from '@testing-library/react';
+import { LocalStorage } from '../../../services/local-storage';
+import { useLocalStorage } from './use-local-storage';
+
+const validator = (value: unknown): value is string =>
+  typeof value === 'string';
+
+describe('useLocalStorage', () => {
+  const fallback = 'fuga';
+  const key = 'qui';
+
+  it('should return the fallback value when storage is clear', () => {
+    LocalStorage.clear();
+
+    const { result } = renderHook(() =>
+      useLocalStorage(key, fallback, validator)
+    );
+
+    expect(result.current[0]).toBe(fallback);
+  });
+
+  it('should return the stored value when storage is not clear', () => {
+    const storedValue = 'unde';
+
+    LocalStorage.set(key, storedValue);
+
+    const { result } = renderHook(() =>
+      useLocalStorage(key, fallback, validator)
+    );
+
+    expect(result.current[0]).toBe(storedValue);
+  });
+
+  it('should return the fallback value when the stored value is invalid', () => {
+    LocalStorage.clear();
+
+    const storedValue = 42;
+
+    LocalStorage.set(key, storedValue);
+
+    const { result } = renderHook(() =>
+      useLocalStorage(key, fallback, validator)
+    );
+
+    expect(result.current[0]).toBe(fallback);
+  });
+
+  it('can update the stored value', () => {
+    const { result } = renderHook(() =>
+      useLocalStorage(key, fallback, validator)
+    );
+    const newValue = 'eveniet';
+
+    act(() => result.current[1](newValue));
+
+    expect(result.current[0]).toBe(newValue);
+  });
+});
diff --git a/src/utils/hooks/use-local-storage/use-local-storage.ts b/src/utils/hooks/use-local-storage/use-local-storage.ts
new file mode 100644
index 0000000..47b98ff
--- /dev/null
+++ b/src/utils/hooks/use-local-storage/use-local-storage.ts
@@ -0,0 +1,38 @@
+import { useEffect, useState } from 'react';
+import { LocalStorage } from '../../../services/local-storage';
+import type { Validator } from '../../../types';
+
+const getInitialValueOrFallback = <T>(
+  key: string,
+  fallbackValue: T,
+  validator: Validator<T>
+) => {
+  if (typeof window === 'undefined') return fallbackValue;
+  const storedValue = LocalStorage.get(key);
+
+  return validator(storedValue) ? storedValue : fallbackValue;
+};
+
+/**
+ * Use the local storage.
+ *
+ * @param {string} key - The storage local key.
+ * @param {T} fallbackValue - A fallback value if local storage is empty.
+ * @param {Validator<T>} validator - A function to validate the stored value.
+ * @returns A tuple with the value and a setter.
+ */
+export const useLocalStorage = <T>(
+  key: string,
+  fallbackValue: T,
+  validator: Validator<T>
+) => {
+  const [value, setValue] = useState(
+    getInitialValueOrFallback(key, fallbackValue, validator)
+  );
+
+  useEffect(() => {
+    LocalStorage.set(key, value);
+  }, [key, value]);
+
+  return [value, setValue] as const;
+};