This is an example showing how to test a server-side meteor method.

methods.test.js

/* eslint-env mocha */
/* eslint-disable func-names, prefer-arrow-callback */

import { Meteor } from 'meteor/meteor';
import { Accounts } from 'meteor/accounts-base';
import { assert } from 'meteor/practicalmeteor:chai';
import { resetDatabase } from 'meteor/xolvio:cleaner';
import { Random } from 'meteor/random';
import { Factory } from 'meteor/dburles:factory';
import './methods.js'; // import all the methods that will be tested
import Appointments from './appointments.js';

if (Meteor.isServer) {
  const delay = milisecs => new Promise(res => setTimeout(() => res(), milisecs));

  describe('Appointments', () => {
    describe('methods', () => {
      const isDefined = target => {
        assert.isNotNull(target, 'unexpected null value');
        assert.isDefined(target, 'unexpected undefined value');

        if (typeof target === 'string') {
          assert.notEqual(target.trim(), '');
        }
      };

      let meteorUserOriginal = null;

      let userId = null;
      let companyId = null;

      let thisContext = null;

      beforeEach(() => {
        resetDatabase();

        meteorUserOriginal = Meteor.user;
        userId = Accounts.createUser({ username: Random.id() });
        companyId = Random.id(5);
        isDefined(userId);

        thisContext = { userId };

        Meteor.user = () => {
          const users = Meteor.users.find({ _id: userId }).fetch();
          if (!users || users.length > 1) {
            throw new Error('Meteor.user() mock cannot find by UserId');
          }
          users[0].companyId = companyId;
          return users[0];
        };
      });

      afterEach(() => {
        Meteor.users.remove(userId);
        Meteor.user = meteorUserOriginal;
        userId = null;
        Appointments.remove();
      });

      it('can insert appointment', function() {
        const appointment = {
          scheduled_services: [Random.id(10), Random.id(10), Random.id(10)],
          type: 'scheduled',
          professional_id: Random.id(10),
          client_id: Random.id(10),
          companyId: Random.id(10),
          date_info: {
            duration: 30,
            start: 900,
            day: new Date(),
          },
          created_at: new Date(),
          updated_at: new Date(),
        };

        const insertAppointment = Meteor.server.method_handlers['Appointments.insert'];

        insertAppointment.apply(thisContext, [appointment]);
        const getAppointment = Appointments.findOne(appointment);
        assert.strictEqual(getAppointment.scheduled_services[0], appointment.scheduled_services[0]);
      });
    });
  });
}