unit testing - How to test node.js websocket server with mocha? -

i need test poker game server, based on websocket.

so, if player1 send message server, server should send message other players.

i write test block below:

describe('protocol', () => {   before(() => {     player1 = new websocket('ws://xxxxxx');     player1 = new websocket('ws://xxxxxx');     player2 = new websocket('ws://xxxxxx');     player3 = new websocket('ws://xxxxxx');   });    it('player1 send message1 player3 should receive' (done) => {      //block1     let message1 = {       id: 'message1',       data: 'message1'     };      player1.send(json.stringify(message1));     player3.once('message', (message) => {        //block2       expect(message).equal(json.stringify(message1)),       done();     });   });    it('player2 send message2 player3 should receive' (done) => {      //block3     let message2 = {       id: 'message2',       data: 'message2'     };      player2.send(json.stringify(message1));     player3.once('message', (message) => {        //block4       expect(message).equal(json.stringify(message2)),       done();     });   }); } 

the order of execution want : block1 -> block2 -> block3 -> block4

but truly:blocks1 -> block3 -> block2 -> block4

so message of block4 message1 instead of message2

how can solve problem?

simply answer move playerx.send(messagex); after playerx.once() , that's it.

just in mind, these call async, order not important, need ready receive before fire something.

describe('protocol', () => {   before(() => {     player1 = new websocket('ws://xxxxxx');     player1 = new websocket('ws://xxxxxx');     player2 = new websocket('ws://xxxxxx');     player3 = new websocket('ws://xxxxxx');   });    it('player1 send message1 player3 should receive', (done) => {      //block1     let message1 = {       id: 'message1',       data: 'message1'     };      player3.once('message', (message) => {        //block2       expect(message).equal(json.stringify(message1));       done();     });     player1.send(json.stringify(message1));   });    it('player2 send message2 player3 should receive', (done) => {      //block3     let message2 = {       id: 'message2',       data: 'message2'     };      player3.once('message', (message) => {        //block4       expect(message).equal(json.stringify(message2));       done();     });   });   player2.send(json.stringify(message1)); }