import { normalizeError } from '../error';

describe('normalizeError', () => {
  it('returns the same error instance when provided', () => {
    const error = new Error('test');
    expect(normalizeError(error)).toBe(error);
  });

  it('converts strings into Error instances', () => {
    const result = normalizeError('failure');
    expect(result).toBeInstanceOf(Error);
    expect(result.message).toBe('failure');
  });

  it('stringifies objects when creating the error message', () => {
    const result = normalizeError({ reason: 'timeout', code: 504 });
    expect(result.message).toBe('{"reason":"timeout","code":504}');
  });

  it('falls back to a generic error for unserializable input', () => {
    const circular: Record<string, unknown> = {};
    circular.self = circular;

    const result = normalizeError(circular);
    expect(result.message).toBe('Unknown error');
  });
});