Styjun

Numbers Decrease while Letters Increase

Can a Rogue PC teach an NPC to perform Sneak Attack?

What is the best type of paint to paint a shipping container?

Heyacrazy: No Diagonals

Why did Khan ask Admiral James T. Kirk about Project Genesis?

Tex Quotes(UVa 272)

How do I make my image comply with the requirements of this photography competition?

Handling Disruptive Student on the Autistic Spectrum

Did anyone try to find the little box that held Professor Moriarty and his wife after the crash?

Where can/should I, as a high schooler, publish a paper regarding the derivation of a formula?

Sum ergo cogito?

How would a Creature that needs to be seen by Humans evolve?

What should come first—characters or plot?

Is there any way white can win?

What does zitch dog mean?

The No-Free-Lunch Theorem and K-NN consistency

Papers on arXiv solving the same problem at the same time

Did a flight controller ever answer Flight with a no-go?

“T” in subscript in formulas

Network helper class with retry logic on failure

How to find out the average duration of the peer-review process for a given journal?

How do we calculate energy of food?

Showing that the limit of non-eigenvector goes to infinity

Nothing like a good ol' game of ModTen

How to mock/test event listeners with mocha/jest?

How to find event listeners on a DOM node when debugging or from the JavaScript code?How do I test for an empty JavaScript object?How to run a single test with Mocha?How to increase timeout for a single test case in mochaHow do you manually mock one of your own files in Jest?How does variable scope work within the Mocha test framework?How do I run a single test using Jest?How to “mock” navigator.geolocation in a React Jest TestJest: Trying to mock nested functions and redirects in jest, but no availHow to handle UnhandledPromiseRejectionWarning in simple Mocha Unit Tests

.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;

2

class Router 
 constructor() 
 window.onhashchange = this.hashChange;
 

 hashChange() 
 console.log('Hash Changed');
 return true;
 


export default Router;

I am trying to find a way to test the above piece of code in node.js. But there is no window object in node. How to mock objects and test event listeners using mocha/jest? The goal is to test that hashChange() is invoked when URL hash is changed

javascript testing mocha jestjs

share|improve this question

edited Apr 5 at 8:10

skyboyer

6,18711 gold badge1717 silver badges3737 bronze badges

asked Mar 27 at 18:30

lchlch

96822 gold badges2424 silver badges5252 bronze badges

add a comment | 

2

class Router 
 constructor() 
 window.onhashchange = this.hashChange;
 

 hashChange() 
 console.log('Hash Changed');
 return true;
 


export default Router;

I am trying to find a way to test the above piece of code in node.js. But there is no window object in node. How to mock objects and test event listeners using mocha/jest? The goal is to test that hashChange() is invoked when URL hash is changed

javascript testing mocha jestjs

share|improve this question

edited Apr 5 at 8:10

skyboyer

6,18711 gold badge1717 silver badges3737 bronze badges

asked Mar 27 at 18:30

lchlch

96822 gold badges2424 silver badges5252 bronze badges

add a comment | 

class Router 
 constructor() 
 window.onhashchange = this.hashChange;
 

 hashChange() 
 console.log('Hash Changed');
 return true;
 


export default Router;

I am trying to find a way to test the above piece of code in node.js. But there is no window object in node. How to mock objects and test event listeners using mocha/jest? The goal is to test that hashChange() is invoked when URL hash is changed

javascript testing mocha jestjs

share|improve this question

edited Apr 5 at 8:10

skyboyer

6,18711 gold badge1717 silver badges3737 bronze badges

asked Mar 27 at 18:30

lchlch

96822 gold badges2424 silver badges5252 bronze badges

class Router 
 constructor() 
 window.onhashchange = this.hashChange;
 

 hashChange() 
 console.log('Hash Changed');
 return true;
 


export default Router;

share|improve this question

edited Apr 5 at 8:10

skyboyer

6,18711 gold badge1717 silver badges3737 bronze badges

asked Mar 27 at 18:30

lchlch

96822 gold badges2424 silver badges5252 bronze badges

share|improve this question

edited Apr 5 at 8:10

skyboyer

6,18711 gold badge1717 silver badges3737 bronze badges

asked Mar 27 at 18:30

lchlch

96822 gold badges2424 silver badges5252 bronze badges

edited Apr 5 at 8:10

skyboyer

6,18711 gold badge1717 silver badges3737 bronze badges

edited Apr 5 at 8:10

skyboyer

6,18711 gold badge1717 silver badges3737 bronze badges

asked Mar 27 at 18:30

lchlch

96822 gold badges2424 silver badges5252 bronze badges

asked Mar 27 at 18:30

lchlch

96822 gold badges2424 silver badges5252 bronze badges

1 Answer
1

active

oldest

votes

2

The default test environment in Jest is a browser-like environment provided by jsdom.

jsdom provides window so it is available by default for tests running in Jest.

You can use Jest to test the above code like this:

class Router 
 constructor() 
 window.onhashchange = this.hashChange;
 

 hashChange() 
 console.log('Hash Changed');
 return true;
 


test('Router', () => 
 const hashChangeSpy = jest.spyOn(Router.prototype, 'hashChange');
 const router = new Router();
 window.onhashchange();
 expect(hashChangeSpy).toHaveBeenCalled(); // Success!
);

share|improve this answer

answered Mar 27 at 19:07

brian-lives-outdoorsbrian-lives-outdoors

15.4k11 gold badge1818 silver badges4545 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  The default test environment in Jest is a browser-like environment provided by jsdom So, do i need to add jsdom to my package.json? or does it come with jest?
  
  – lch
  Mar 27 at 19:54
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @lch it’s included with jest and is used automatically with the default configuration settings
  
  – brian-lives-outdoors
  Mar 27 at 20:11
  

  
  
  
  

add a comment | 

Your Answer

StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "1"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f55384258%2fhow-to-mock-test-event-listeners-with-mocha-jest%23new-answer', 'question_page');

);

Post as a guest

Name

Email

Required, but never shown

2

The default test environment in Jest is a browser-like environment provided by jsdom.

jsdom provides window so it is available by default for tests running in Jest.

You can use Jest to test the above code like this:

class Router 
 constructor() 
 window.onhashchange = this.hashChange;
 

 hashChange() 
 console.log('Hash Changed');
 return true;
 


test('Router', () => 
 const hashChangeSpy = jest.spyOn(Router.prototype, 'hashChange');
 const router = new Router();
 window.onhashchange();
 expect(hashChangeSpy).toHaveBeenCalled(); // Success!
);

share|improve this answer

answered Mar 27 at 19:07

brian-lives-outdoorsbrian-lives-outdoors

15.4k11 gold badge1818 silver badges4545 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  The default test environment in Jest is a browser-like environment provided by jsdom So, do i need to add jsdom to my package.json? or does it come with jest?
  
  – lch
  Mar 27 at 19:54
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @lch it’s included with jest and is used automatically with the default configuration settings
  
  – brian-lives-outdoors
  Mar 27 at 20:11
  

  
  
  
  

add a comment | 

2

The default test environment in Jest is a browser-like environment provided by jsdom.

jsdom provides window so it is available by default for tests running in Jest.

You can use Jest to test the above code like this:

class Router 
 constructor() 
 window.onhashchange = this.hashChange;
 

 hashChange() 
 console.log('Hash Changed');
 return true;
 


test('Router', () => 
 const hashChangeSpy = jest.spyOn(Router.prototype, 'hashChange');
 const router = new Router();
 window.onhashchange();
 expect(hashChangeSpy).toHaveBeenCalled(); // Success!
);

share|improve this answer

answered Mar 27 at 19:07

brian-lives-outdoorsbrian-lives-outdoors

15.4k11 gold badge1818 silver badges4545 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  The default test environment in Jest is a browser-like environment provided by jsdom So, do i need to add jsdom to my package.json? or does it come with jest?
  
  – lch
  Mar 27 at 19:54
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @lch it’s included with jest and is used automatically with the default configuration settings
  
  – brian-lives-outdoors
  Mar 27 at 20:11
  

  
  
  
  

add a comment | 

The default test environment in Jest is a browser-like environment provided by jsdom.

jsdom provides window so it is available by default for tests running in Jest.

You can use Jest to test the above code like this:

class Router 
 constructor() 
 window.onhashchange = this.hashChange;
 

 hashChange() 
 console.log('Hash Changed');
 return true;
 


test('Router', () => 
 const hashChangeSpy = jest.spyOn(Router.prototype, 'hashChange');
 const router = new Router();
 window.onhashchange();
 expect(hashChangeSpy).toHaveBeenCalled(); // Success!
);

share|improve this answer

answered Mar 27 at 19:07

brian-lives-outdoorsbrian-lives-outdoors

15.4k11 gold badge1818 silver badges4545 bronze badges

class Router 
 constructor() 
 window.onhashchange = this.hashChange;
 

 hashChange() 
 console.log('Hash Changed');
 return true;
 


test('Router', () => 
 const hashChangeSpy = jest.spyOn(Router.prototype, 'hashChange');
 const router = new Router();
 window.onhashchange();
 expect(hashChangeSpy).toHaveBeenCalled(); // Success!
);

share|improve this answer

answered Mar 27 at 19:07

brian-lives-outdoorsbrian-lives-outdoors

15.4k11 gold badge1818 silver badges4545 bronze badges

answered Mar 27 at 19:07

brian-lives-outdoorsbrian-lives-outdoors

15.4k11 gold badge1818 silver badges4545 bronze badges

answered Mar 27 at 19:07

brian-lives-outdoorsbrian-lives-outdoors

15.4k11 gold badge1818 silver badges4545 bronze badges