Added Unit Test for BackButton component (#136)

src/__tests__/unit/components/BackButton.test.tsx

@@ -0,0 +1,60 @@
+import { cleanup, fireEvent, render, screen } from "@testing-library/react"
+import { useRouter } from "next/navigation"
+import { afterEach, describe, expect, it, vi } from "vitest"
+
+import { BackButton } from "@/components/back-button"
+// Mock the next/navigation useRouter hook
+const mockPush = vi.fn()
+const mockBack = vi.fn()
+
+vi.mock("next/navigation", () => ({
+    useRouter: () => ({
+        push: mockPush,
+        back: mockBack,
+    }),
+}))
+describe("BackButton Component", () => {
+    afterEach(() => {
+        cleanup()
+    })
+
+    it("should navigate back if no route prop is provided", () => {
+        const { back } = useRouter()
+        render(<BackButton />)
+
+        const button = screen.getByRole("button", { name: /back/i })
+        fireEvent.click(button)
+
+        expect(back).toHaveBeenCalledTimes(1) // Check that 'back' is called
+    })
+
+    it("should navigate to the provided route when route prop is specified", () => {
+        const { push } = useRouter()
+        render(<BackButton route="/home" />)
+
+        const button = screen.getByRole("button", { name: /back/i })
+        fireEvent.click(button)
+
+        expect(push).toHaveBeenCalledWith("/home") // Check that 'push' is called with the correct route
+    })
+
+    it('should render with default label "Back" if no label is provided', () => {
+        render(<BackButton />)
+
+        const button = screen.getByRole("button", { name: /back/i })
+        expect(button).toBeTruthy()
+    })
+
+    it("should render the correct label when label prop is provided", () => {
+        render(<BackButton label="Go Home" />)
+
+        const button = screen.getByRole("button", { name: /go home/i })
+        expect(button).toBeTruthy()
+    })
+
+    it("should render left arrow icon", () => {
+        render(<BackButton />)
+        const arrowLeftIcon = document.querySelector("svg")
+        expect(arrowLeftIcon).toBeTruthy()
+    })
+})