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

3 files changed, 119 insertions, 26 deletions

diff --git a/src/services/local-storage/index.ts b/src/services/local-storage/index.ts
index 65235a7..72dd18f 100644
--- a/src/services/local-storage/index.ts
+++ b/src/services/local-storage/index.ts
@@ -1,26 +1 @@
-export const LocalStorage = {
-  get<T>(key: string): T | undefined {
-    try {
-      const serialItem = localStorage.getItem(key);
-      if (!serialItem) return undefined;
-      return JSON.parse(serialItem) as T;
-    } catch (e) {
-      console.log(e);
-      return undefined;
-    }
-  },
-  set<T>(key: string, value: T) {
-    try {
-      const serialItem = JSON.stringify(value);
-      localStorage.setItem(key, serialItem);
-    } catch (e) {
-      console.log(e);
-    }
-  },
-  remove(key: string) {
-    localStorage.removeItem(key);
-  },
-  clear() {
-    localStorage.clear();
-  },
-};
+export * from './local-storage';
diff --git a/src/services/local-storage/local-storage.test.ts b/src/services/local-storage/local-storage.test.ts
new file mode 100644
index 0000000..df3c646
--- /dev/null
+++ b/src/services/local-storage/local-storage.test.ts
@@ -0,0 +1,92 @@
+import { describe, expect, it, jest } from '@jest/globals';
+import { LocalStorage } from './local-storage';
+
+describe('LocalStorage', () => {
+  it('should return an undefined value when the key is not set', () => {
+    localStorage.clear();
+
+    expect(LocalStorage.get('et')).toBeUndefined();
+  });
+
+  it('can set a new key and return its value', () => {
+    localStorage.clear();
+
+    const key = 'laudantium';
+    const value = 'laborum';
+
+    LocalStorage.set(key, value);
+
+    expect(LocalStorage.get(key)).toBe(value);
+  });
+
+  it('can update an existing key', () => {
+    localStorage.clear();
+
+    const key = 'officiis';
+    const value = 'saepe';
+
+    LocalStorage.set(key, value);
+
+    const newValue = 'itaque';
+
+    LocalStorage.set(key, newValue);
+
+    expect(LocalStorage.get(key)).toBe(newValue);
+  });
+
+  it('can remove a key from the storage', () => {
+    localStorage.clear();
+
+    const key1 = 'ab';
+    const value1 = 'ipsum';
+    const key2 = 'suscipit';
+    const value2 = 'autem';
+
+    LocalStorage.set(key1, value1);
+    LocalStorage.set(key2, value2);
+    LocalStorage.remove(key1);
+
+    expect(LocalStorage.get(key1)).toBeUndefined();
+    expect(LocalStorage.get(key2)).toBe(value2);
+  });
+
+  it('can clear the storage', () => {
+    localStorage.clear();
+
+    const key1 = 'velit';
+    const value1 = 'rerum';
+    const key2 = 'enim';
+    const value2 = 'consequatur';
+
+    LocalStorage.set(key1, value1);
+    LocalStorage.set(key2, value2);
+    LocalStorage.clear();
+
+    expect(LocalStorage.get(key1)).toBeUndefined();
+    expect(LocalStorage.get(key2)).toBeUndefined();
+  });
+
+  it('return undefined and log and error when the value is invalid', () => {
+    const spy = jest.spyOn(console, 'error');
+    const key = 'dolor';
+    const value = 'possimus';
+
+    // The value is not stringified
+    localStorage.setItem(key, value);
+
+    expect(LocalStorage.get(key)).toBeUndefined();
+    expect(spy).toHaveBeenCalled();
+  });
+
+  it('does not set invalid value and log the error', () => {
+    const spy = jest.spyOn(console, 'error');
+    const key = 'voluptatibus';
+    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
+    const value = BigInt(1234567890);
+
+    LocalStorage.set(key, value);
+
+    expect(LocalStorage.get(key)).toBeUndefined();
+    expect(spy).toHaveBeenCalled();
+  });
+});
diff --git a/src/services/local-storage/local-storage.ts b/src/services/local-storage/local-storage.ts
new file mode 100644
index 0000000..e9a50a5
--- /dev/null
+++ b/src/services/local-storage/local-storage.ts
@@ -0,0 +1,26 @@
+export const LocalStorage = {
+  get<T>(key: string): T | undefined {
+    try {
+      const serialItem = localStorage.getItem(key);
+      if (!serialItem) return undefined;
+      return JSON.parse(serialItem) as T;
+    } catch (e) {
+      console.error(e);
+      return undefined;
+    }
+  },
+  set<T>(key: string, value: T) {
+    try {
+      const serialItem = JSON.stringify(value);
+      localStorage.setItem(key, serialItem);
+    } catch (e) {
+      console.error(e);
+    }
+  },
+  remove(key: string) {
+    localStorage.removeItem(key);
+  },
+  clear() {
+    localStorage.clear();
+  },
+};