avocado/packages/core/test/property.js

import {expect} from 'chai';
import Property from '../src/property';

describe('Property', () => {
  it("dies if meta isn't an object", () => {
    expect(() => {
      Property('property', 420)(class {});
    }).to.throw();
  });
  it('dies if duplicate properties are defined', () => {
    expect(() => {
      Property('property')(class {property() {}});
    }).to.throw();
  });
  it('accepts initializer', () => {
    let hasInitialized = false;
    class Class extends Property('property', {
      initialize() {
        hasInitialized = this instanceof Class;
      },
    })(class {}) {};
    const object = new Class();
    expect(hasInitialized).to.be.true;
  });
  it('accepts defaults', () => {
    class Class extends Property('property', {
      default: 420,
    })(class {}) {};
    const object = new Class();
    expect(object.property).to.equal(420);
  });
  it('accepts getter', () => {
    class Class extends Property('property', {
      default: 69,
      get() {
        return 420;
      },
    })(class {}) {};
    const object = new Class();
    expect(object.property).to.equal(420);
  });
  it('accepts setter', () => {
    let s;
    class Class extends Property('property', {
      set(value) {
        s = value;
      },
    })(class {}) {};
    const object = new Class();
    object.property = 420;
    expect(s).to.equal(420);
  });
  it('tracks property values', () => {
    let emitted = false;
    class Class extends Property('property', {
      track: true,
    })(class {}) {
      emit(type, o, v) {emitted = ('propertyChanged' === type && 420 === v)}
    };
    const object = new Class();
    expect(emitted).to.be.false;
    object.property = 420;
    expect(emitted).to.be.true;
  });
  it('accepts emitter', () => {
    let emitted = false;
    class Class extends Property('property', {
      emit: (type, o, v) => {
        emitted = ('propertyChanged' === type && 420 === v);
      },
      track: true,
    })(class {}) {};
    const object = new Class();
    expect(emitted).to.be.false;
    object.property = 420;
    expect(emitted).to.be.true;
  });
  it('accepts comparator', () => {
    let emitted = false;
    const emit = (type, o, v) => {
      emitted = ('propertyChanged' === type);
    };
    class Class extends Property('property', {
      default: [0, 0],
      emit,
      eq: (l, r) => l[0] === r[0] && l[1] === r[1],
      track: true,
    })(class {}) {};
    const object = new Class();
    expect(emitted).to.be.false;
    object.property = [0, 0];
    expect(emitted).to.be.false;
    object.property = [1, 0];
    expect(emitted).to.be.true;
  });
});