diff --git a/src/__tests__/components/DeleteModal.test.tsx b/src/__tests__/components/DeleteModal.test.tsx
new file mode 100644
index 0000000..0737f52
--- /dev/null
+++ b/src/__tests__/components/DeleteModal.test.tsx
@@ -0,0 +1,102 @@
+import React from 'react';
+import { render, screen, fireEvent, waitFor } from '@testing-library/react';
+import '@testing-library/jest-dom';
+import { DeleteModal } from '../../components/base/DeleteModal';
+
+describe('DeleteModal', () => {
+  const defaultProps = {
+    isOpen: true,
+    onClose: jest.fn(),
+    onConfirm: jest.fn().mockResolvedValue(undefined),
+    title: 'Supprimer la campagne',
+    description: 'Êtes-vous sûr de vouloir supprimer cette campagne ?',
+    itemName: 'Campagne Test',
+    itemDetails: <div>Détails de la campagne à supprimer</div>,
+  };
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('should render modal when open', () => {
+    render(<DeleteModal {...defaultProps} />);
+
+    expect(screen.getByText('Supprimer la campagne')).toBeInTheDocument();
+    expect(screen.getByText('Êtes-vous sûr de vouloir supprimer cette campagne ?')).toBeInTheDocument();
+    expect(screen.getByText('Campagne Test à supprimer :')).toBeInTheDocument();
+  });
+
+  it('should not render modal when closed', () => {
+    render(<DeleteModal {...defaultProps} isOpen={false} />);
+
+    expect(screen.queryByText('Supprimer la campagne')).not.toBeInTheDocument();
+  });
+
+  it('should call onConfirm when delete button is clicked', async () => {
+    const onConfirm = jest.fn().mockResolvedValue(undefined);
+    render(<DeleteModal {...defaultProps} onConfirm={onConfirm} />);
+
+    const deleteButton = screen.getByRole('button', { name: /supprimer définitivement/i });
+    fireEvent.click(deleteButton);
+
+    await waitFor(() => {
+      expect(onConfirm).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  it('should call onClose when cancel button is clicked', () => {
+    const onClose = jest.fn();
+    render(<DeleteModal {...defaultProps} onClose={onClose} />);
+
+    const cancelButton = screen.getByRole('button', { name: /annuler/i });
+    fireEvent.click(cancelButton);
+
+    expect(onClose).toHaveBeenCalledTimes(1);
+  });
+
+  it('should show loading state during deletion', async () => {
+    const onConfirm = jest.fn().mockImplementation(() => new Promise(resolve => setTimeout(resolve, 100)));
+    render(<DeleteModal {...defaultProps} onConfirm={onConfirm} />);
+
+    const deleteButton = screen.getByRole('button', { name: /supprimer définitivement/i });
+    fireEvent.click(deleteButton);
+
+    await waitFor(() => {
+      expect(screen.getByText('Suppression...')).toBeInTheDocument();
+    });
+  });
+
+  it('should render with custom confirm text', () => {
+    render(
+      <DeleteModal 
+        {...defaultProps} 
+        confirmText="Oui, supprimer définitivement"
+      />
+    );
+
+    expect(screen.getByRole('button', { name: /oui, supprimer définitivement/i })).toBeInTheDocument();
+  });
+
+  it('should show warning message', () => {
+    render(<DeleteModal {...defaultProps} />);
+
+    expect(screen.getByText(/⚠️ Cette action est irréversible./)).toBeInTheDocument();
+  });
+
+  it('should show custom warning message', () => {
+    render(
+      <DeleteModal 
+        {...defaultProps} 
+        warningMessage="Attention, cette suppression est définitive !"
+      />
+    );
+
+    expect(screen.getByText(/⚠️ Attention, cette suppression est définitive !/)).toBeInTheDocument();
+  });
+
+  it('should display item details', () => {
+    render(<DeleteModal {...defaultProps} />);
+
+    expect(screen.getByText('Détails de la campagne à supprimer')).toBeInTheDocument();
+  });
+});
diff --git a/src/__tests__/components/ErrorDisplay.test.tsx b/src/__tests__/components/ErrorDisplay.test.tsx
new file mode 100644
index 0000000..0e79c53
--- /dev/null
+++ b/src/__tests__/components/ErrorDisplay.test.tsx
@@ -0,0 +1,63 @@
+import React from 'react';
+import { render, screen } from '@testing-library/react';
+import '@testing-library/jest-dom';
+import { ErrorDisplay } from '../../components/base/ErrorDisplay';
+
+describe('ErrorDisplay', () => {
+  it('should render error message when error is provided', () => {
+    const error = 'Une erreur est survenue';
+    render(<ErrorDisplay error={error} />);
+
+    expect(screen.getByText('Une erreur est survenue')).toBeInTheDocument();
+    expect(screen.getByText('Une erreur est survenue')).toHaveClass('text-red-600');
+  });
+
+  it('should not render when no error is provided', () => {
+    render(<ErrorDisplay error="" />);
+
+    expect(screen.queryByText('Une erreur est survenue')).not.toBeInTheDocument();
+  });
+
+  it('should not render when error is null', () => {
+    render(<ErrorDisplay error={null} />);
+
+    expect(screen.queryByText('Une erreur est survenue')).not.toBeInTheDocument();
+  });
+
+  it('should not render when error is undefined', () => {
+    render(<ErrorDisplay error={undefined} />);
+
+    expect(screen.queryByText('Une erreur est survenue')).not.toBeInTheDocument();
+  });
+
+  it('should handle long error messages', () => {
+    const longError = 'A'.repeat(500);
+    render(<ErrorDisplay error={longError} />);
+
+    expect(screen.getByText(longError)).toBeInTheDocument();
+  });
+
+  it('should handle special characters in error message', () => {
+    const specialError = 'Erreur avec des caractères spéciaux: @#$%^&*()_+{}|:"<>?[]\\;\',./';
+    render(<ErrorDisplay error={specialError} />);
+
+    expect(screen.getByText(specialError)).toBeInTheDocument();
+  });
+
+  it('should handle HTML in error message', () => {
+    const htmlError = '<script>alert("xss")</script>Erreur avec HTML';
+    render(<ErrorDisplay error={htmlError} />);
+
+    expect(screen.getByText(htmlError)).toBeInTheDocument();
+    // Vérifier que le HTML n'est pas interprété
+    expect(screen.queryByText('xss')).not.toBeInTheDocument();
+  });
+
+  it('should have proper accessibility attributes', () => {
+    const error = 'Erreur d\'accessibilité';
+    render(<ErrorDisplay error={error} />);
+
+    const errorElement = screen.getByText(error);
+    expect(errorElement).toHaveAttribute('role', 'alert');
+  });
+});
diff --git a/src/__tests__/lib/markdown.test.ts b/src/__tests__/lib/markdown.test.ts
new file mode 100644
index 0000000..90d7896
--- /dev/null
+++ b/src/__tests__/lib/markdown.test.ts
@@ -0,0 +1,67 @@
+import { parseMarkdown } from '../../lib/markdown';
+
+describe('Markdown Module', () => {
+  describe('parseMarkdown', () => {
+    it('should parse basic markdown', () => {
+      const markdown = '# Titre\n\nContenu **gras** et *italique*.';
+      const result = parseMarkdown(markdown);
+      
+      expect(result).toContain('<h1>Titre</h1>');
+      expect(result).toContain('<strong>gras</strong>');
+      expect(result).toContain('<em>italique</em>');
+    });
+
+    it('should handle empty string', () => {
+      const result = parseMarkdown('');
+      expect(result).toBe('');
+    });
+
+    it('should handle null/undefined', () => {
+      expect(parseMarkdown(null as any)).toBe('');
+      expect(parseMarkdown(undefined as any)).toBe('');
+    });
+
+    it('should handle links', () => {
+      const markdown = '[Lien](https://example.com)';
+      const result = parseMarkdown(markdown);
+      
+      expect(result).toContain('<a href="https://example.com"');
+      expect(result).toContain('>Lien</a>');
+    });
+
+    it('should handle lists', () => {
+      const markdown = '- Item 1\n- Item 2\n- Item 3';
+      const result = parseMarkdown(markdown);
+      
+      expect(result).toContain('<ul>');
+      expect(result).toContain('<li>Item 1</li>');
+      expect(result).toContain('<li>Item 2</li>');
+      expect(result).toContain('<li>Item 3</li>');
+    });
+  });
+
+  describe('renderMarkdown', () => {
+    it('should render markdown to HTML', () => {
+      const markdown = '**Texte en gras**';
+      const result = parseMarkdown(markdown);
+      
+      expect(result).toContain('<strong>Texte en gras</strong>');
+    });
+
+    it('should handle code blocks', () => {
+      const markdown = '```javascript\nconsole.log("test");\n```';
+      const result = parseMarkdown(markdown);
+      
+      expect(result).toContain('```javascript');
+      expect(result).toContain('console.log("test");');
+      expect(result).toContain('```');
+    });
+
+    it('should handle inline code', () => {
+      const markdown = 'Utilisez `console.log()` pour afficher.';
+      const result = parseMarkdown(markdown);
+      
+      expect(result).toContain('`console.log()`');
+    });
+  });
+});
diff --git a/src/components/base/ErrorDisplay.tsx b/src/components/base/ErrorDisplay.tsx
index c4b26ef..a1d0d7f 100644
--- a/src/components/base/ErrorDisplay.tsx
+++ b/src/components/base/ErrorDisplay.tsx
@@ -8,7 +8,7 @@ export function ErrorDisplay({ error, className = "" }: ErrorDisplayProps) {
   
   return (
     <div className={`p-3 bg-red-50 dark:bg-red-900/20 border border-red-200 dark:border-red-800 rounded-lg ${className}`}>
-      <p className="text-sm text-red-600 dark:text-red-400">{error}</p>
+      <p className="text-sm text-red-600 dark:text-red-400" role="alert">{error}</p>
     </div>
   );
 }