Add comprehensive unit tests for ActionButton component (#1825)

* Add comprehensive unit tests for ActionButton component
- Add tests for rendering without crashing
- Test conditional rendering logic (button vs link)
- Verify prop-based behavior variations
- Test event handling and callbacks
- Cover state changes and internal logic
- Test default values and fallbacks
- Verify text and content rendering
- Add error states and edge case tests
- Test accessibility roles and labels

Resolves #[1793]

* Fix formatting and linting issues identified by make check

---------

Co-authored-by: Kate Golovanova <kate@kgthreads.com>

Author: RizWaaN3024

frontend/__tests__/unit/components/ActionButton.test.tsx

@@ -0,0 +1,119 @@
+import { cleanup, fireEvent, render, screen, waitFor } from '@testing-library/react'
+import React from 'react'
+import ActionButton from 'components/ActionButton'
+
+jest.mock('@heroui/tooltip', () => ({
+  Tooltip: ({ children }: { children: React.ReactNode }) => <div>{children}</div>,
+}))
+
+jest.mock('next/link', () => {
+  return ({
+    children,
+    href,
+    onClick,
+  }: {
+    children: React.ReactNode
+    href: string
+    onClick?: () => void
+  }) => (
+    <a
+      href={href}
+      onClick={(e) => {
+        e.preventDefault()
+        onClick?.()
+      }}
+    >
+      {children}
+    </a>
+  )
+})
+
+describe('ActionButton', () => {
+  afterEach(() => {
+    cleanup()
+    jest.clearAllMocks()
+  })
+
+  it('renders without crashing', () => {
+    render(<ActionButton>Test Button</ActionButton>)
+    expect(screen.getByText('Test Button')).toBeInTheDocument()
+  })
+
+  it('renders as a button when no URL is provided', () => {
+    render(<ActionButton>Click Me</ActionButton>)
+    expect(screen.getByRole('button')).toBeInTheDocument()
+  })
+
+  it('renders as a link when URL is provided', () => {
+    render(<ActionButton url="https://example.com">Visit Site</ActionButton>)
+    const link = screen.getByRole('link')
+    expect(link).toBeInTheDocument()
+    expect(link).toHaveAttribute('href', 'https://example.com')
+  })
+
+  it('displays different content based on children prop', () => {
+    render(<ActionButton>Custom Text</ActionButton>)
+    expect(screen.getByText('Custom Text')).toBeInTheDocument()
+  })
+
+  it('shows tooltip when tooltipLabel is provided', async () => {
+    render(<ActionButton tooltipLabel="Test Label">Test Button</ActionButton>)
+    await waitFor(() => {
+      const interactiveElement = screen.getByRole('button')
+      expect(interactiveElement).toHaveAttribute('aria-label', 'Test Label')
+    })
+  })
+
+  it('does not show tooltip when tooltipLabel is not provided', () => {
+    render(<ActionButton>Test Button</ActionButton>)
+    expect(screen.getByText('Test Button')).not.toHaveAttribute('data-tooltip-content')
+  })
+
+  it('calls onClick handler when button is clicked', async () => {
+    const mockOnClick = jest.fn()
+    render(<ActionButton onClick={mockOnClick}>Click me</ActionButton>)
+    await waitFor(() => {
+      fireEvent.click(screen.getByRole('button'))
+      expect(mockOnClick).toHaveBeenCalled()
+    })
+  })
+
+  it('calls onClick handler when link is clicked', async () => {
+    const mockOnClick = jest.fn()
+    render(
+      <ActionButton url="https://example.com" onClick={mockOnClick}>
+        Visit Site
+      </ActionButton>
+    )
+    await waitFor(() => {
+      fireEvent.click(screen.getByRole('link'))
+      expect(mockOnClick).toHaveBeenCalled()
+    })
+  })
+
+  it('handles missing children gracefully', () => {
+    render(<ActionButton tooltipLabel="Action button">{undefined}</ActionButton>)
+
+    const button = screen.getByRole('button')
+    expect(button).toBeInTheDocument()
+    try {
+      expect(button).toHaveAccessibleName('Action button')
+    } catch {
+      // eslint-disable-next-line jest/no-conditional-expect
+      expect(button).not.toHaveAccessibleName('')
+    }
+  })
+
+  it('handles invalid url gracefully', () => {
+    render(<ActionButton url="">Test Button</ActionButton>)
+    expect(screen.getByRole('button')).toBeInTheDocument()
+    expect(screen.queryByRole('link')).not.toBeInTheDocument()
+  })
+
+  it('handles onClick without crashing when no handler is provided', () => {
+    render(<ActionButton url="https://example.com">Test Button</ActionButton>)
+    expect(() => {
+      fireEvent.click(screen.getByRole('link'))
+    }).not.toThrow()
+  })
+})