From dd5c1efd83b62bb7fa8d1ef35c572f1da9544ba0 Mon Sep 17 00:00:00 2001
From: Ward Oosterlijnck <wardoosterlijnck@gmail.com>
Date: Tue, 7 May 2019 20:39:28 +1000
Subject: [PATCH] usePrevious tests

---
 src/__tests__/usePrevious.test.tsx | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 src/__tests__/usePrevious.test.tsx

diff --git a/src/__tests__/usePrevious.test.tsx b/src/__tests__/usePrevious.test.tsx
new file mode 100644
index 00000000..70713653
--- /dev/null
+++ b/src/__tests__/usePrevious.test.tsx
@@ -0,0 +1,22 @@
+import { cleanup, renderHook } from 'react-hooks-testing-library';
+import usePrevious from '../usePrevious';
+
+afterEach(cleanup);
+
+describe('usePrevious', () => {
+  it('should be defined', () => {
+    expect(usePrevious).toBeDefined();
+  });
+
+  const hook = renderHook(props => usePrevious(props), { initialProps: 0 });
+
+  it('should return undefined on initial render', () => {
+    expect(hook.result.current).toBe(undefined);
+  });
+
+  it('should return previous state after update', () => {
+    hook.rerender(1);
+    hook.rerender(2);
+    expect(hook.result.current).toBe(1);
+  });
+});