text: /* global source, describe, it, each, expect */
  
  const factory = source('main');
  const ISO15924 = source('ValueObject/ISO15924');
  
  describe('ISO 15924', () => {
  	describe('Zsym - Symbols', () => {
  		const zsym = factory('Zsym');
  
  		it('instances are singletons', (next) => {
  			const singleton = factory('Zsym');
  			const upper = factory('ZSYM');
  			const lower = factory('zsym');
  			const code = factory.code('Zsym');
  			const numeric = factory.numeric('996');
  			const number = factory.numeric(996);
  			const instance = new ISO15924('Zsym', '996');
  
  			expect(singleton).to.shallow.equal(zsym);
  			expect(upper).to.shallow.equal(zsym);
  			expect(lower).to.shallow.equal(zsym);
  			expect(code).to.shallow.equal(zsym);
  			expect(numeric).to.shallow.equal(zsym);
  			expect(number).to.shallow.equal(zsym);
  			expect(instance).not.to.shallow.equal(zsym);
  			expect(instance.code).to.equal(zsym.code);
  			expect(instance.numeric).to.equal(zsym.numeric);
  
  			next();
  		});
  
  		it('has code "Zsym"', (next) => {
  			expect(zsym.code).to.equal('Zsym');
  
  			next();
  		});
  
  		it('has numeric "996"', (next) => {
  			expect(zsym.numeric).to.equal('996');
  
  			next();
  		});
  
  		it('implements toString', (next) => {
  			expect(zsym.toString).to.be.function();
  			expect(zsym.toString()).to.equal('Zsym');
  			expect(String(zsym)).to.equal('Zsym');
  			expect(0 + zsym).to.equal('0Zsym');
  			expect('code:' + zsym).to.equal('code:Zsym');
  
  			next();
  		});
  
  		it('implements toJSON', (next) => {
  			expect(zsym.toJSON).to.be.function();
  			expect(zsym.toJSON()).to.equal('Zsym');
  			expect(JSON.stringify(zsym)).to.equal('"Zsym"');
  
  			next();
  		});
  
  		it('implements valueOf', (next) => {
  			expect(zsym.valueOf).to.be.function();
  			expect(zsym.valueOf()).to.equal(996);
  			expect(Number(zsym)).to.equal(996);
  			expect(+zsym).to.equal(996);
  
  			next();
  		});
  
  		it('implements Symbol.toPrimitive', (next) => {
  			expect(zsym.valueOf).to.be.function();
  			expect(zsym.valueOf()).to.equal(996);
  			expect(Number(zsym)).to.equal(996);
  			expect(+zsym).to.equal(996);
  
  			expect(0 + zsym).to.equal('0Zsym');
  			expect(String(zsym)).to.equal('Zsym');
  
  			next();
  		});
  	});
  });
  