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Simplify repetitive Jest test cases with test.each

Bartosz Gordon on May 06, 2019

Problem From time to time, I run into a situation, where most of my test cases follow a similar sequence of steps. This scenario most of...
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Harish Rajora

Great article on simplifying Jest test cases! It's always helpful to explore different approaches to streamline testing processes. Speaking of testing, I recently came across a comprehensive guide on running Jest Testing with Selenium and JavaScript. It covers everything from setup to execution and provides valuable insights. If anyone is interested in expanding their testing capabilities, I highly recommend checking it out. how to run Jest Testing with Selenium and JavaScript Keep up the excellent content!"

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Jose E Saura

Hey I really liked this example.

Is there a way to make something similar but the difference would be in 1 test the element is in the document and the other test the element is NOT in the document.

I kinda have an idea but I think what I thought is too much abstraction and unnecesary.

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sammy kapienga

This was just a nice article.Thanks so much Gordon

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makaveli1313

Thank you, so much easier to understand then in the docs!

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makaveli1313

Any idea of how to use just the second argument in the text?
"given %p and %p as arguments, returns %p",

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Amnon Sadeh • Edited
  1. Change the order of the arguments so the previously second becomes first.
  2. Use the "Tagged Template Literal" variant as described in the docs: jestjs.io/docs/en/api#testeachtabl...
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Nonary

You'll have to use both of them, but the convention is if you're not using a parameter you should name it a single underscore _

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Joel Coll

What is the benefit of using the test.each of jest instead of js for each? I think it is more readable and friendly the js way

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Maxime Péloquin

Using test.each will create one test for each test case, so if it fails, you will know exactly which test case failed. It will also run the rest of the test cases even if one failed.

If you use for each, then your entire test will fail on the first case failure, and you will not know which one failed quickly.

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Antonio Luis Román

That's not completely true. You can put an it inside a forEach loop and get the same behavior.

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machy44

this is exactly what I needed. tnx for the article

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Daniel H.

How do you deal with cases where you have over 100,000 possible combinations you want to test out?

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Vk

Thanks. Simple use case helped grasp the concept quickly.

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Roberto La Greca • Edited

Really nice solution. Thanks.

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Sai Sumanth Lokinindi

Thank you, this article is so much simple to understand

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Isaac Hagoel

thanks. this was helpful

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kurtisas-k

Thank-you! I'm just beginning to implement tests today, I've known about them for years, but only dabbled. And finally now I have a use! And a great tutorial thanks to you.