Use `loopback-testing` module with mongodb

KPIndex.test.js

// path: <project>/test/KPIndex.test.js
require('debug').enable('loopback:connector:*'); //enable namespace
var debug = require('debug')('loopback:connector:*'); //reload debug

var lt = require('loopback-testing');
var assert = require('assert');
var app = require('../server/server.js'); //path to app.js or server.js

var KpIndex;

var TestDataBuilder = require('loopback-testing').TestDataBuilder;
var ref = TestDataBuilder.ref;

// The context object to hold the created models.
// You can use `this` in mocha test instead.
var context = {};

var ref = TestDataBuilder.ref;


// Connect to db
//console.log(app);
//console.log(app.datasources.mongodb);
var dbConnector = app.datasources.mongodb;


/**
 * Tests for KPIndex route
 */
describe('/KpIndex', function() {
  this.timeout(5000);
  lt.beforeEach.withApp(app);

  /**
   * Wait for app to get started
   * @Todo modify to real async processing instead of only wait and hope.
   */
  beforeEach(function(done){
    //setTimeout(done,1000);

    // Create a new model and attach the mixin
    var KpIndices = this.KpIndices = app.PersistedModel.extend(
      'kp-indice',
      {name: String},
      {}
    );

    // Attach model to db
    KpIndices.attachTo(dbConnector);
    app.model(KpIndices);
    app.use(loopback.rest());
    app.set('legacyExplorer', false);
    new lt.TestDataBuilder()
      .define('kp-indice', KpIndices, {
        name: 'Item name'
      })
      .buildTo(this, done);
  });

  lt.describe.whenCalledRemotely('GET', '/api/KpIndices', function () {

    lt.it.shouldBeAllowed();
    it('should have statusCode 200', function() {
      assert.equal(this.res.statusCode, 200);
    });

    lt.beforeEach.givenModel('KpIndex',{
      date: new Date()
    });
    it('should respond with an array of KpIndices', function () {
      assert(Array.isArray(this.res.body));

    });
  });

  lt.describe.whenCalledRemotely('GET', '/api/KpIndices/count', function () {

    lt.it.shouldBeAllowed();
    it('should have statusCode 200', function() {
      assert.equal(this.res.statusCode, 200);
    });

    it('should respond with an number ', function () {
      assert.notEqual(this.res.body.count, undefined);
      assert.ok(this.res.body.count > 0);


    });
  });

  lt.describe.whenCalledRemotely('GET', '/api/KpIndices/current', function () {

    lt.it.shouldBeAllowed();
    it('should have statusCode 200', function() {
      assert.equal(this.res.statusCode, 200);
    });

    it('should respond with one KPIndex entry ', function () {

      assert(this.res.body instanceof  Object);
      assert(this.res.body.hasOwnProperty("date"));
      assert(this.res.body.hasOwnProperty("utc"));
      assert(this.res.body.hasOwnProperty("kpValue"));

    });
  });


  lt.describe.whenCalledRemotely('GET', '/api/KpIndices/prediction', function () {

    lt.it.shouldBeAllowed();
    it('should have statusCode 200', function() {
      assert.equal(this.res.statusCode, 200);
    });

    lt.beforeEach.givenModel('KpIndex',{
      date: new Date()
    });
    it('should respond with an array of KpIndices', function () {
      assert(Array.isArray(this.res.body));


    });

    it('should return more then one item', function () {
      assert.ok(this.res.body.length > 1)
    });

    //assert.equal(results.length, 0);

  });
});


lt.describe.whenCalledRemotely('GET', '/api/KpIndices/prediction/daily', function () {

  lt.it.shouldBeAllowed();
  it('should have statusCode 200', function() {
    assert.equal(this.res.statusCode, 200);
  });

  lt.beforeEach.givenModel('KpIndex',{
    date: new Date()
  });
  it('should respond with an array of KpIndices', function () {
    assert(Array.isArray(this.res.body));


  });

  it('should return exact 3 items', function () {
    assert.ok(this.res.body.length === 3 )
  });

});

refer to https://github.com/ShoppinPal/loopback-mongo-sandbox/tree/master/test for latest stable attempts at making loopback-testing work with mongodb