From 9c967a8fd3f30daf7125ad1591998472daf05923 Mon Sep 17 00:00:00 2001
From: Andrea Salvatore <andrea.salvatore@consensys.net>
Date: Mon, 14 Oct 2024 10:17:00 +0200
Subject: [PATCH] chore: adds unit tests

---
 app/selectors/hooks.test.ts | 48 +++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 app/selectors/hooks.test.ts

diff --git a/app/selectors/hooks.test.ts b/app/selectors/hooks.test.ts
new file mode 100644
index 00000000000..a91b37efbec
--- /dev/null
+++ b/app/selectors/hooks.test.ts
@@ -0,0 +1,48 @@
+import { renderHook } from '@testing-library/react-hooks';
+import { useSelector } from 'react-redux';
+import { useChainId } from './hooks';
+import { selectChainId } from '../selectors/networkController';
+
+// Mock useSelector from react-redux
+jest.mock('react-redux', () => ({
+  useSelector: jest.fn(),
+}));
+
+// Mock the selector
+jest.mock('../selectors/networkController', () => ({
+  selectChainId: jest.fn(),
+}));
+
+describe('useChainId hook', () => {
+  afterEach(() => {
+    jest.clearAllMocks(); // Clear mocks after each test to avoid test contamination
+  });
+
+  it('should return the chain ID from the redux store', () => {
+    const mockChainId = 1;
+
+    // Mock the selector to return the mockChainId
+    (useSelector as jest.Mock).mockImplementation((selectorFn) => {
+      if (selectorFn === selectChainId) {
+        return mockChainId;
+      }
+    });
+
+    const { result } = renderHook(() => useChainId());
+
+    expect(result.current).toBe(mockChainId);
+  });
+
+  it('should return undefined if the chain ID is not set', () => {
+    // Mock the selector to return undefined
+    (useSelector as jest.Mock).mockImplementation((selectorFn) => {
+      if (selectorFn === selectChainId) {
+        return undefined;
+      }
+    });
+
+    const { result } = renderHook(() => useChainId());
+
+    expect(result.current).toBeUndefined();
+  });
+});