spec/predicates/isInstanceOf.spec.ts

import 'mocha';

import { given } from 'mocha-testdata';

import { ensure, isInstanceOf, TinyType } from '../../src';
import { expect } from '../expect';

describe('predicates', () => {

    /** @test {isInstanceOf} */
    describe('::isInstanceOf', () => {
        class Birthday extends TinyType {
            constructor(public readonly value: Date) {
                super();

                ensure('Birthday', value, isInstanceOf(Date));
            }
        }

        it('ensures that the argument is an instance of Date', () => {
            expect(() => new Birthday(new Date())).to.not.throw();
        });

        given([
            '2018-10-10',
            undefined,
            null,
            {},
            'string',
        ]).
        it('complains if the value does not meet the predicate', (value: any) => {
            expect(() => new Birthday(value)).to.throw(`Birthday should be instance of Date`);
        });
    });
});