From 42168f8a7cb459700ac5ae8bf7b320c0f1bb18c1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B4natas=20Rancan=20de=20Souza?=
 <jonatasrancan@gmail.com>
Date: Thu, 18 Jul 2019 17:06:04 -0300
Subject: [PATCH] Solves #16 - Add unit tests for useSlider hook

---
 tests/hooks/useSlider.test.js | 101 ++++++++++++++++++++++++++++++++--
 1 file changed, 96 insertions(+), 5 deletions(-)

diff --git a/tests/hooks/useSlider.test.js b/tests/hooks/useSlider.test.js
index a6f07b6..85128ff 100644
--- a/tests/hooks/useSlider.test.js
+++ b/tests/hooks/useSlider.test.js
@@ -1,10 +1,101 @@
-import { renderHook } from 'react-hooks-testing-library'
+import { renderHook, cleanup, act } from 'react-hooks-testing-library'
 import useSlider from '@hooks/useSlider'
 
 describe('useSlider()', () => {
-  test('Describe what you are testing', () => {
-    const { result } = renderHook(() => useSlider())
-    const { activeSlide } = result.current
-    expect(activeSlide).toBe(50)
+  beforeEach(cleanup)
+
+  describe('activeSlide integer response', () => {
+    test('returns 0 when theres no default value', () => {
+      const { result } = renderHook(() => useSlider())
+      const { activeSlide } = result.current
+      expect(activeSlide).toBe(0)
+    })
+
+    test('uses the activeSlide config value if provided', () => {
+      const config = { initialSlide: 3 }
+      const { result } = renderHook(() => useSlider(5, config))
+      const { activeSlide } = result.current
+      expect(activeSlide).toBe(3)
+    })
+  })
+
+  describe('nextSlide integer response', () => {
+    describe('when activeSlide is the last slide on the right', () => {
+      test('returns activeSlide', () => {
+        const config = { initialSlide: 1, infinite: false }
+        const { result } = renderHook(() => useSlider(2, config))
+        const { nextSlide } = result.current
+
+        expect(nextSlide).toBe(config.initialSlide)
+      })
+    })
+
+    describe("when activeSlide isn't the last slide on the right", () => {
+      test('returns activeSlide plus one', () => {
+        const config = { initialSlide: 1 }
+        const { result } = renderHook(() => useSlider(3, config))
+        const { nextSlide } = result.current
+
+        expect(nextSlide).toBe(config.initialSlide + 1)
+      })
+    })
+  })
+
+  describe('prevSlide integer response', () => {
+    describe('when activeSlide is the last slide on the left', () => {
+      test('returns activeSlide', () => {
+        const config = { initialSlide: 0, infinite: false }
+        const { result } = renderHook(() => useSlider(2, config))
+        const { prevSlide } = result.current
+
+        expect(prevSlide).toBe(config.initialSlide)
+      })
+    })
+
+    describe("when activeSlide isn't the last slide on the left", () => {
+      test('returns activeSlide minus one', () => {
+        const config = { initialSlide: 2 }
+        const { result } = renderHook(() => useSlider(3, config))
+        const { prevSlide } = result.current
+
+        expect(prevSlide).toBe(config.initialSlide - 1)
+      })
+    })
+  })
+
+  describe('goToSlide()', () => {
+    it('sets activeSlide to the passed index', () => {
+      const config = { initialSlide: 0 }
+      const { result, rerender } = renderHook(() => useSlider(2, config))
+      const { goToSlide } = result.current
+
+      act(() => goToSlide(1))
+
+      expect(result.current.activeSlide).toBe(1)
+    })
+  })
+
+  describe('goToNextSlide()', () => {
+    it('sets activeSlide to the nextSlide', () => {
+      const config = { initialSlide: 1 }
+      const { result, rerender } = renderHook(() => useSlider(3, config))
+      const { goToNextSlide } = result.current
+
+      act(() => goToNextSlide())
+
+      expect(result.current.activeSlide).toBe(2)
+    })
+  })
+
+  describe('goToPrevSlide()', () => {
+    it('sets activeSlide to the prevSlide', () => {
+      const config = { initialSlide: 2 }
+      const { result, rerender } = renderHook(() => useSlider(3, config))
+      const { goToPrevSlide } = result.current
+
+      act(() => goToPrevSlide())
+
+      expect(result.current.activeSlide).toBe(1)
+    })
   })
 })