Can we use Jest for unit test?

General
1

The example in the document uses mocha for unit test using de-red-node-test-helper .
Can we use Jest to test node?

2

We've not tried it, but please be our guest and try it for us. Feedback would be welcome.

3

You can use whatever you want. There is nothing tied to mocha in the test helper - it just provides a convenient way to start/stop the runtime with a test config.

4

I gave it a try and got stumbled upon async loading

$ jest
 FAIL  test/flow.test.js
  Dummy Node
    ✓ should be loaded (22 ms)
    ✕ should make payload lower case (6 ms)

  ● Dummy Node › should make payload lower case

    TypeError: Attempted to wrap log which is already wrapped

      39 |          { id: "n2", type: "helper" }
      40 |      ];
    > 41 |     helper.load(targetNode, flow, function () {
         |            ^
      42 |       var n2 = helper.getNode("n2");
      43 |       var n1 = helper.getNode("n1");
      44 |       n2.on("input", function (msg) {

      at checkWrappedMethod (node_modules/sinon/lib/sinon/util/core/wrap-method.js:64:21)
      at wrapMethod (node_modules/sinon/lib/sinon/util/core/wrap-method.js:135:13)
      at Function.spy (node_modules/sinon/lib/sinon/spy.js:180:16)
      at Sandbox.spy (node_modules/sinon/lib/sinon/sandbox.js:383:35)
      at NodeTestHelper.load (node_modules/node-red-node-test-helper/index.js:178:53)
      at Object.load (test/flow.test.js:41:12)
      --------------
      Error: Stack Trace for original
      at extendObjectWithWrappedMethods (node_modules/sinon/lib/sinon/util/core/wrap-method.js:169:34)
      at wrapMethod (node_modules/sinon/lib/sinon/util/core/wrap-method.js:157:5)
      at Function.spy (node_modules/sinon/lib/sinon/spy.js:180:16)
      at Sandbox.spy (node_modules/sinon/lib/sinon/sandbox.js:383:35)
      at NodeTestHelper.load (node_modules/node-red-node-test-helper/index.js:178:53)
      at Object.load (test/flow.test.js:25:12)

Test Suites: 1 failed, 1 total
Tests:       1 failed, 1 passed, 2 total
Snapshots:   0 total
Time:        1.044 s, estimated 2 s
Ran all test suites.

here is my test code

"use strict";
var should = require('should');
var helper = require("node-red-node-test-helper");
const fs = require('fs');
const Path = require('path');
var targetNode = require("../node.js");

helper.init(require.resolve('node-red'));

beforeAll(function (done) {
	helper.startServer(done);
});

afterAll( (done) => {
	helper.unload().then(function() {
        helper.stopServer(done);
	});
});

describe('Dummy Node', () => {
//  this.timeout(10000);

  it('should be loaded', (done) => {
    var flow = [{ id: "n1", type: "dummy", name: "dummy node" }];
    helper.load(targetNode, flow, function () {
      var n1 = helper.getNode("n1");
      try {
        expect(n1.name).toEqual('dummy node');
        done();
      } catch (e) {
        done(e)
      }
    });
  });
});