Medium-Jest-Test

system.test.js

const mongoose = require('mongoose');
const factory = require('../factories/systemFactory');
const System = mongoose.model('System');
const Celestial = mongoose.model('Celestial');

process.env.TEST_SUITE = 'spacetime-systems-test';

describe('Systems', () => {
  beforeEach(() => {
    System.ensureIndexes({ loc: '2d' });
  });
  describe('CREATE', () => {
    let systems;

    beforeEach(async () => {
      systems = await factory.makeSystems(50);
    });
    test('can create a system', async () => {
      await new System({
        name: 'Sol',
        type: 'white_star',
        loc: [10, 10],
      }).save();
      const system = await System.findOne({ name: 'Sol' });

      expect(system.name).toEqual('Sol');
    });
    test('can create random systems', async () => {
      const fetchedSystems = await System.find({});

      expect(fetchedSystems.length).toEqual(50);
    });
  });
  describe('READ', () => {
    let systems;

    beforeEach(async () => {
      systems = await factory.makeSystems(50);
    });
    test('target system can find nearest system to it', async () => {
      const nearest = await systems[0].findClosest();

      expect(systems.map(system => system.name)).toContain(nearest.name);
    });
    test('target system can find nearest systems within specified range', async () => {
      const noSystems = await systems[0].findWithinRange(0);
      const someSystems = await systems[0].findWithinRange(50);

      expect(systems.length).toEqual(50);
      expect(noSystems.length).toEqual(0);
      expect(someSystems.length).toBeGreaterThan(0);
      expect(someSystems.length).toBeLessThan(50);
    });
  });
  describe('DELETE', () => {
    let systems;

    beforeEach(async () => {
      const newSystems = await factory.makeSystems(2);
      await Promise.all(newSystems.map(system => system.addCelestials(5)));
      systems = await System.find({});
    });
    test('should delete system and associated celestials', async () => {
      await systems[0].remove();
      const remainingSystems = await System.find({});
      const remainingCelestials = await Celestial.find({});

      expect(remainingSystems.length).toEqual(1);
      expect(remainingCelestials.length).toEqual(5);
    });
  });
});