emi-challenge-fe/tests/app/shared/utils/form-validators.util.spec.ts

import { describe, it, expect, vi, afterEach } from 'vitest';
import { FormControl, FormGroup } from '@angular/forms';
import { futureDateValidator, atLeastOneFilledValidator, trimmedRequiredValidator } from '@app/shared/utils/form-validators.util';

describe('form-validators.util', () => {
  afterEach(() => {
    vi.useRealTimers();
  });

  describe('futureDateValidator', () => {
    it('should return null for empty value', () => {
      const control = new FormControl('');

      const result = futureDateValidator(control);

      expect(result).toBeNull();
    });

    it('should return null for future date', () => {
      vi.useFakeTimers();
      vi.setSystemTime(new Date('2026-05-13T12:00:00'));
      const control = new FormControl('2030-01-01');

      const result = futureDateValidator(control);

      expect(result).toBeNull();
    });

    it('should return error for past date', () => {
      vi.useFakeTimers();
      vi.setSystemTime(new Date('2026-05-13T12:00:00'));
      const control = new FormControl('2020-01-01');

      const result = futureDateValidator(control);

      expect(result).toEqual({ futureDate: { value: '2020-01-01' } });
    });

    it('should return error for today', () => {
      vi.useFakeTimers();
      vi.setSystemTime(new Date('2026-05-13T12:00:00'));
      const control = new FormControl('2026-05-13');

      const result = futureDateValidator(control);

      expect(result).toEqual({ futureDate: { value: '2026-05-13' } });
    });
  });

  describe('atLeastOneFilledValidator', () => {
    it('should return null when at least one field has value', () => {
      const group = new FormGroup({
        title: new FormControl('Hello'),
        description: new FormControl(''),
      });

      const result = atLeastOneFilledValidator('title', 'description')(group);

      expect(result).toBeNull();
    });

    it('should return error when all fields are empty', () => {
      const group = new FormGroup({
        title: new FormControl(''),
        description: new FormControl(''),
      });

      const result = atLeastOneFilledValidator('title', 'description')(group);

      expect(result).toEqual({ atLeastOneFilled: { fields: ['title', 'description'] } });
    });

    it('should return error when all fields are whitespace only', () => {
      const group = new FormGroup({
        title: new FormControl('   '),
        description: new FormControl('  '),
      });

      const result = atLeastOneFilledValidator('title', 'description')(group);

      expect(result).toEqual({ atLeastOneFilled: { fields: ['title', 'description'] } });
    });
  });

  describe('trimmedRequiredValidator', () => {
    it('should return null for non-empty trimmed string', () => {
      const control = new FormControl('hello');

      const result = trimmedRequiredValidator(control);

      expect(result).toBeNull();
    });

    it('should return error for empty string', () => {
      const control = new FormControl('');

      const result = trimmedRequiredValidator(control);

      expect(result).toEqual({ trimmedRequired: { value: '' } });
    });

    it('should return error for whitespace only', () => {
      const control = new FormControl('   ');

      const result = trimmedRequiredValidator(control);

      expect(result).toEqual({ trimmedRequired: { value: '   ' } });
    });

    it('should return error for non-string value', () => {
      const control = new FormControl(null);

      const result = trimmedRequiredValidator(control);

      expect(result).toEqual({ trimmedRequired: { value: null } });
    });
  });
});