diff --git a/src/utils/errorHandling.test.ts b/src/utils/errorHandling.test.ts
new file mode 100644
index 0000000..e79e349
--- /dev/null
+++ b/src/utils/errorHandling.test.ts
@@ -0,0 +1,165 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { AppError, errorCodes, handleError, createAPIError } from './errorHandling';
+import * as analytics from './analytics';
+
+// Mock the analytics module
+vi.mock('./analytics', () => ({
+  trackEvent: vi.fn()
+}));
+
+describe('errorHandling', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  describe('AppError', () => {
+    it('should create an AppError with all properties', () => {
+      const error = new AppError('Test error', 'TEST_CODE', 'error', { key: 'value' });
+
+      expect(error).toBeInstanceOf(Error);
+      expect(error).toBeInstanceOf(AppError);
+      expect(error.message).toBe('Test error');
+      expect(error.code).toBe('TEST_CODE');
+      expect(error.severity).toBe('error');
+      expect(error.metadata).toEqual({ key: 'value' });
+      expect(error.name).toBe('AppError');
+    });
+
+    it('should create an AppError with default severity', () => {
+      const error = new AppError('Test error', 'TEST_CODE');
+
+      expect(error.severity).toBe('error');
+      expect(error.metadata).toBeUndefined();
+    });
+
+    it('should create an AppError with warning severity', () => {
+      const error = new AppError('Test warning', 'TEST_CODE', 'warning');
+
+      expect(error.severity).toBe('warning');
+    });
+
+    it('should create an AppError with info severity', () => {
+      const error = new AppError('Test info', 'TEST_CODE', 'info');
+
+      expect(error.severity).toBe('info');
+    });
+  });
+
+  describe('errorCodes', () => {
+    it('should have all error codes defined', () => {
+      expect(errorCodes.NETWORK_ERROR).toBe('ERR_NETWORK');
+      expect(errorCodes.API_ERROR).toBe('ERR_API');
+      expect(errorCodes.AUTH_ERROR).toBe('ERR_AUTH');
+      expect(errorCodes.VALIDATION_ERROR).toBe('ERR_VALIDATION');
+      expect(errorCodes.UNKNOWN_ERROR).toBe('ERR_UNKNOWN');
+    });
+  });
+
+  describe('handleError', () => {
+    it('should handle AppError and return it unchanged', () => {
+      const originalError = new AppError('Test error', 'TEST_CODE', 'error', { foo: 'bar' });
+      const result = handleError(originalError, 'test-context');
+
+      expect(result).toBe(originalError);
+      expect(result.message).toBe('Test error');
+      expect(result.code).toBe('TEST_CODE');
+      expect(result.severity).toBe('error');
+      expect(result.metadata).toEqual({ foo: 'bar' });
+      expect(analytics.trackEvent).toHaveBeenCalledWith(
+        'Error',
+        'TEST_CODE',
+        'test-context: Test error'
+      );
+    });
+
+    it('should convert regular Error to AppError', () => {
+      const originalError = new Error('Regular error');
+      const result = handleError(originalError, 'test-context');
+
+      expect(result).toBeInstanceOf(AppError);
+      expect(result.message).toBe('Regular error');
+      expect(result.code).toBe(errorCodes.UNKNOWN_ERROR);
+      expect(result.severity).toBe('error');
+      expect(result.metadata).toEqual({ originalError });
+      expect(analytics.trackEvent).toHaveBeenCalledWith(
+        'Error',
+        errorCodes.UNKNOWN_ERROR,
+        'test-context: Regular error'
+      );
+    });
+
+    it('should handle unknown error types', () => {
+      const result = handleError('string error', 'test-context');
+
+      expect(result).toBeInstanceOf(AppError);
+      expect(result.message).toBe('An unexpected error occurred');
+      expect(result.code).toBe(errorCodes.UNKNOWN_ERROR);
+      expect(result.severity).toBe('error');
+      expect(result.metadata).toEqual({ originalError: 'string error' });
+      expect(analytics.trackEvent).toHaveBeenCalledWith(
+        'Error',
+        errorCodes.UNKNOWN_ERROR,
+        'test-context: An unexpected error occurred'
+      );
+    });
+
+    it('should handle null error', () => {
+      const result = handleError(null, 'test-context');
+
+      expect(result).toBeInstanceOf(AppError);
+      expect(result.message).toBe('An unexpected error occurred');
+      expect(result.code).toBe(errorCodes.UNKNOWN_ERROR);
+      expect(result.metadata).toEqual({ originalError: null });
+    });
+
+    it('should handle undefined error', () => {
+      const result = handleError(undefined, 'test-context');
+
+      expect(result).toBeInstanceOf(AppError);
+      expect(result.message).toBe('An unexpected error occurred');
+      expect(result.code).toBe(errorCodes.UNKNOWN_ERROR);
+      expect(result.metadata).toEqual({ originalError: undefined });
+    });
+
+    it('should track error in analytics', () => {
+      const error = new AppError('Analytics test', 'ANALYTICS_CODE');
+      handleError(error, 'analytics-context');
+
+      expect(analytics.trackEvent).toHaveBeenCalledTimes(1);
+      expect(analytics.trackEvent).toHaveBeenCalledWith(
+        'Error',
+        'ANALYTICS_CODE',
+        'analytics-context: Analytics test'
+      );
+    });
+  });
+
+  describe('createAPIError', () => {
+    it('should create an API error with status code', () => {
+      const error = createAPIError(404, 'Not found');
+
+      expect(error).toBeInstanceOf(AppError);
+      expect(error.message).toBe('Not found');
+      expect(error.code).toBe(errorCodes.API_ERROR);
+      expect(error.severity).toBe('error');
+      expect(error.metadata).toEqual({ status: 404 });
+    });
+
+    it('should create an API error for 500 status', () => {
+      const error = createAPIError(500, 'Internal server error');
+
+      expect(error).toBeInstanceOf(AppError);
+      expect(error.message).toBe('Internal server error');
+      expect(error.code).toBe(errorCodes.API_ERROR);
+      expect(error.metadata).toEqual({ status: 500 });
+    });
+
+    it('should create an API error for 401 status', () => {
+      const error = createAPIError(401, 'Unauthorized');
+
+      expect(error).toBeInstanceOf(AppError);
+      expect(error.message).toBe('Unauthorized');
+      expect(error.metadata).toEqual({ status: 401 });
+    });
+  });
+});