test: add comprehensive unit tests for all components, API routes, and lib functions

__tests__/components/ArticleBody.test.tsx

@@ -0,0 +1,33 @@
+import { describe, it, expect } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import ArticleBody from '@/components/article/ArticleBody'
+
+describe('ArticleBody', () => {
+  it('renders HTML content', () => {
+    render(<ArticleBody html="<p>Hello world</p>" />)
+    expect(screen.getByText('Hello world')).toBeInTheDocument()
+  })
+
+  it('renders multiple HTML elements', () => {
+    render(<ArticleBody html="<h1>Title</h1><p>Paragraph</p>" />)
+    expect(screen.getByText('Title')).toBeInTheDocument()
+    expect(screen.getByText('Paragraph')).toBeInTheDocument()
+  })
+
+  it('applies the article-body class', () => {
+    const { container } = render(<ArticleBody html="<p>Test</p>" />)
+    expect(container.firstChild).toHaveClass('article-body')
+  })
+
+  it('renders complex HTML including images and links', () => {
+    const html = '<p>Text with <a href="/test">a link</a> and <img src="img.jpg" alt="pic" /></p>'
+    render(<ArticleBody html={html} />)
+    expect(screen.getByText('a link')).toBeInTheDocument()
+    expect(screen.getByAltText('pic')).toBeInTheDocument()
+  })
+
+  it('renders empty string without crashing', () => {
+    const { container } = render(<ArticleBody html="" />)
+    expect(container.firstChild).toBeInTheDocument()
+  })
+})