1 files changed, 73 insertions, 0 deletions
diff --git a/frontend/test/components/Header.test.js b/frontend/test/components/Header.test.js
new file mode 100644
index 0000000..d6bf564
--- /dev/null
+++ b/frontend/test/components/Header.test.js
@@ -0,0 +1,73 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest'
+import { setupThemeToggle } from '../../src/components/Header.js'
+
+// Mock DOM elements
+const mockDocument = {
+    documentElement: {
+        getAttribute: vi.fn(),
+        setAttribute: vi.fn()
+    },
+    getElementById: vi.fn()
+}
+
+global.document = mockDocument
+
+describe('Header', () => {
+    beforeEach(() => {
+        vi.clearAllMocks()
+    })
+
+    describe('toggleDarkMode', () => {
+        it('should toggle from dark to light theme', () => {
+            // Setup: current theme is dark
+            mockDocument.documentElement.getAttribute.mockReturnValue('dark')
+
+            const mockElement = {
+                addEventListener: vi.fn()
+            }
+            mockDocument.getElementById.mockReturnValue(mockElement)
+
+            // Get the toggle function by setting up the event listener
+            setupThemeToggle()
+            const clickHandler = mockElement.addEventListener.mock.calls[0][1]
+
+            // Execute the toggle function
+            clickHandler()
+
+            expect(mockDocument.documentElement.setAttribute).toHaveBeenCalledWith('data-theme', 'light')
+        })
+
+        it('should toggle from light to dark theme', () => {
+            // Setup: current theme is light
+            mockDocument.documentElement.getAttribute.mockReturnValue('light')
+
+            const mockElement = {
+                addEventListener: vi.fn()
+            }
+            mockDocument.getElementById.mockReturnValue(mockElement)
+
+            setupThemeToggle()
+            const clickHandler = mockElement.addEventListener.mock.calls[0][1]
+
+            clickHandler()
+
+            // This should work correctly
+            expect(mockDocument.documentElement.setAttribute).toHaveBeenCalledWith('data-theme', 'dark')
+        })
+
+
+        describe('setupThemeToggle', () => {
+            it('should add click event listener to theme toggle button', () => {
+                const mockElement = {
+                    addEventListener: vi.fn()
+                }
+                mockDocument.getElementById.mockReturnValue(mockElement)
+
+                setupThemeToggle()
+
+                expect(mockDocument.getElementById).toHaveBeenCalledWith('theme')
+                expect(mockElement.addEventListener).toHaveBeenCalledWith('click', expect.any(Function))
+            })
+        })
+    })
+});
+\ No newline at end of file