import { expectType } from 'ts-data-forge';
import { number } from '../primitives/index.mjs';
import {
  isOptionalProperty,
  optional,
  type OptionalPropertyType,
} from './optional.mjs';

describe(optional, () => {
  const numberType = number(42);

  const optionalNumber = optional(numberType);

  type OptionalNumber = OptionalPropertyType<typeof numberType>;

  expectType<typeof optionalNumber, OptionalNumber>('=');

  describe('optional function', () => {
    test('creates optional property type', () => {
      assert.deepStrictEqual(optionalNumber, {
        ...numberType,
        optional: true,
      });

      expect(optionalNumber.defaultValue).toBe(42);
    });

    test('preserves original type properties', () => {
      expect(optionalNumber.defaultValue).toBe(42);

      expect(optionalNumber.typeName).toBe('number');
    });
  });

  describe(isOptionalProperty, () => {
    test('returns true for optional property', () => {
      assert.isTrue(isOptionalProperty(optionalNumber));
    });

    test('returns false for non-optional property', () => {
      assert.isFalse(isOptionalProperty(numberType));
    });

    test('returns false for object without optional key', () => {
      const { optional: _, ...obj } = { ...numberType } as const;

      assert.isFalse(isOptionalProperty(obj));
    });
  });
});