n4s/src/rules/schemaRules/__tests__/optional.test.ts

typed schema validation version of enforce

import { describe, it, expect } from 'vitest';

import { enforce } from '../../../n4s';

// schema combinators are accessed via enforce

describe('optional', () => {
  it('should return a rule instance', () => {
    const rule = enforce.optional(enforce.isNumber());
    expect(rule).toHaveProperty('run');
    expect(rule).toHaveProperty('infer');
  });

  it('should pass for null', () => {
    const rule = enforce.optional(enforce.isNumber());
    const result = rule.run(null);
    expect(result.pass).toBe(true);
  });

  it('should pass for undefined', () => {
    const rule = enforce.optional(enforce.isNumber());
    const result = rule.run(undefined);
    expect(result.pass).toBe(true);
  });

  it('should pass for a valid value', () => {
    const rule = enforce.optional(enforce.isNumber());
    const result = rule.run(123);
    expect(result.pass).toBe(true);
  });

  it('should fail for an invalid value', () => {
    const rule = enforce.optional(enforce.isNumber());
    // @ts-expect-error - testing runtime failure with invalid type
    const result = rule.run('not a number');
    expect(result.pass).toBe(false);
  });
});

describe('optional - eager API', () => {
  it('should pass for null (eager)', () => {
    expect(() => {
      enforce(null).optional(enforce.isNumber());
    }).not.toThrow();
  });

  it('should pass for undefined (eager)', () => {
    expect(() => {
      enforce(undefined).optional(enforce.isNumber());
    }).not.toThrow();
  });

  it('should pass for a valid value (eager)', () => {
    expect(() => {
      enforce(123).optional(enforce.isNumber());
    }).not.toThrow();
  });

  it('should fail for an invalid value (eager)', () => {
    expect(() => {
      enforce('not a number').optional(enforce.isNumber());
    }).toThrow();
  });
});