Alfie Mellor

Alfie Mellor

1558623735

Introduction To Testing With Jest

Why should I write tests?

As software developers, it is our prime responsibility to ensure that we ship apps that are of high quality. Now, how do you know if your app passes the quality test? Well, writing tests to validate the app if one of the fundamental tasks that we need to do as software developers.

Often times, we tend to skip writing tests for our code. And we may have plenty of reasons like meeting deadlines, client doesn’t care about tests, and so on. I believe, writing tests needs to be a part of our everyday job, and we should integrate it within the process.

Alright, enough said about the importance of testing.

If you are developing in JavaScript, one of the most popular and easy to use testing frameworks out there today is Jest.

What is Jest?

**Jest **is a JavaScript testing framework that is widely popular today. It works with all modern JavaScript frameworks like React, Angular, Vue, Node and so on.

If you are someone who hates writing tests, Jest will change your opinion. It is super easy to use and developers love writing tests with Jest.

Tell me more, what is cool about Jest?

No configuration

Remember how long it takes to set-up a testing framework and integrate it within your app. Well, Jest makes things a lot easier and comes with no configuration at all. It comes out of the box on most modern JavaScript frameworks and requires no setup time. Hence, saving you tons of developer time. I use Jest with my React and React Native applications with zero configuration.

Simple Mocking

Jest makes writing mock functions quite simple. It uses custom resolver for imports in your tests, hence making it easy to mock any object that is outside of your test’s scope.

Snapshots

Jest uses snapshots that can make your test keep track of large objects in an organized manner. Snapshots live either alongside your tests, or are embedded inline. This is useful, if you have a huge object stored in the redux store, and want to validate it’s data.

Tests run in Parallel

This is one of the distinguishing feature of Jest, making it suitable for fast paced development. The tests run parallely, in isolation. Since they have their own processes, it maximizes the performance.

Fast

Since tests run in parallel, Jest is a fast option for testing. It also runs previously failed tests first, and re-organizes test runs based on how long test files take.

Great Documentation

Jest APIs are documented clearly and are easy to use. You can browse through the Jest APIs to get an idea on how to get started.

If you are interested to learn more about Jest, the talk below from the core team will provide a lot of insights.

Code Coverage

Jest can generate code coverage by simply using the *–coverage *command. No additional setup is needed to generate the coverage report. This can be used to validate your test cases, and predict how many more test cases are needed to achieve better coverage.

Snapshot Testing with Jest

Snapshot testing ensures that your UI does not change in an unexpected manner. The idea is simple. An initial snapshot of UI component is taken, and it is compared to it’s reference snapshot file stored in the test. The test will fail, if the two snapshots don’t match. This will indicate to us that either, the change is unexpected, or the reference snapshot needs to be updated to the latest version of the UI component.

These types of testing are really common while testing mobile applications.

Jest supports snapshot testing your React/React Native components. You may think, it could be a hassle to constantly update the reference snapshots as your UI changes. Jest has this process simplified for you. You would just need to run one command to update the snapshots and the new reference snapshot replaces the old one.

Here is more information from the official blog, on snapshot testing using Jest.

Moving to Jest from an existing codebase

Not everyone is starting a new project all the time. In reality, if you are on an existing codebase with another testing framework and would like to migrate to Jest, it is quite simple.

  • If you are on Jasmine or Mocha, Jest is compatible with these frameworks and the migration is simple.
  • For other frameworks, you can use the codemods to transform your tests automatically.

Migrating existing tests with jest-codemods

Install the third party plugin, jest-codemods. It can be used to handle all the work to migrate these tests.

yarn global add jest-codemods

To transform your existing tests, navigate to the project containing the tests and run:

jest-codemods

Who is using Jest?

Jest is used today by many fortune 500 companies to test their products.

It was originally developed by Facebook and has been open sourced for the community to use and contribute to.

Facebook, Twitter, Airbnb, Instagram, Spotify, and many more big players and small startups are all using this framework to test their products that are written in JavaScript.

The state of JavaScript 2018 survey, shows that Jest is the most popular and widely used testing framework for JavaScript. And about 39.6% of the developers have used it and would use it again.

https://2018.stateofjs.com/testing/overview/

Jest is a solid testing framework and I highly recommend that you give it a shot.

If you liked this article, do share and spread the word.

#testing #javascript

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Buddha Community

Introduction To Testing With Jest
Tamia  Walter

Tamia Walter

1596754901

Testing Microservices Applications

The shift towards microservices and modular applications makes testing more important and more challenging at the same time. You have to make sure that the microservices running in containers perform well and as intended, but you can no longer rely on conventional testing strategies to get the job done.

This is where new testing approaches are needed. Testing your microservices applications require the right approach, a suitable set of tools, and immense attention to details. This article will guide you through the process of testing your microservices and talk about the challenges you will have to overcome along the way. Let’s get started, shall we?

A Brave New World

Traditionally, testing a monolith application meant configuring a test environment and setting up all of the application components in a way that matched the production environment. It took time to set up the testing environment, and there were a lot of complexities around the process.

Testing also requires the application to run in full. It is not possible to test monolith apps on a per-component basis, mainly because there is usually a base code that ties everything together, and the app is designed to run as a complete app to work properly.

Microservices running in containers offer one particular advantage: universal compatibility. You don’t have to match the testing environment with the deployment architecture exactly, and you can get away with testing individual components rather than the full app in some situations.

Of course, you will have to embrace the new cloud-native approach across the pipeline. Rather than creating critical dependencies between microservices, you need to treat each one as a semi-independent module.

The only monolith or centralized portion of the application is the database, but this too is an easy challenge to overcome. As long as you have a persistent database running on your test environment, you can perform tests at any time.

Keep in mind that there are additional things to focus on when testing microservices.

  • Microservices rely on network communications to talk to each other, so network reliability and requirements must be part of the testing.
  • Automation and infrastructure elements are now added as codes, and you have to make sure that they also run properly when microservices are pushed through the pipeline
  • While containerization is universal, you still have to pay attention to specific dependencies and create a testing strategy that allows for those dependencies to be included

Test containers are the method of choice for many developers. Unlike monolith apps, which lets you use stubs and mocks for testing, microservices need to be tested in test containers. Many CI/CD pipelines actually integrate production microservices as part of the testing process.

Contract Testing as an Approach

As mentioned before, there are many ways to test microservices effectively, but the one approach that developers now use reliably is contract testing. Loosely coupled microservices can be tested in an effective and efficient way using contract testing, mainly because this testing approach focuses on contracts; in other words, it focuses on how components or microservices communicate with each other.

Syntax and semantics construct how components communicate with each other. By defining syntax and semantics in a standardized way and testing microservices based on their ability to generate the right message formats and meet behavioral expectations, you can rest assured knowing that the microservices will behave as intended when deployed.

Ways to Test Microservices

It is easy to fall into the trap of making testing microservices complicated, but there are ways to avoid this problem. Testing microservices doesn’t have to be complicated at all when you have the right strategy in place.

There are several ways to test microservices too, including:

  • Unit testing: Which allows developers to test microservices in a granular way. It doesn’t limit testing to individual microservices, but rather allows developers to take a more granular approach such as testing individual features or runtimes.
  • Integration testing: Which handles the testing of microservices in an interactive way. Microservices still need to work with each other when they are deployed, and integration testing is a key process in making sure that they do.
  • End-to-end testing: Which⁠—as the name suggests⁠—tests microservices as a complete app. This type of testing enables the testing of features, UI, communications, and other components that construct the app.

What’s important to note is the fact that these testing approaches allow for asynchronous testing. After all, asynchronous development is what makes developing microservices very appealing in the first place. By allowing for asynchronous testing, you can also make sure that components or microservices can be updated independently to one another.

#blog #microservices #testing #caylent #contract testing #end-to-end testing #hoverfly #integration testing #microservices #microservices architecture #pact #testing #unit testing #vagrant #vcr

Software Testing 101: Regression Tests, Unit Tests, Integration Tests

Automation and segregation can help you build better software
If you write automated tests and deliver them to the customer, he can make sure the software is working properly. And, at the end of the day, he paid for it.

Ok. We can segregate or separate the tests according to some criteria. For example, “white box” tests are used to measure the internal quality of the software, in addition to the expected results. They are very useful to know the percentage of lines of code executed, the cyclomatic complexity and several other software metrics. Unit tests are white box tests.

#testing #software testing #regression tests #unit tests #integration tests

Jamal  Lemke

Jamal Lemke

1603587600

Agile Testing: An introduction

When we talk about Agile the first thing that pops into our mind is Agile development. But here we are going to see and learn about an introduction to Agile Testing that how testers work in Agile, the contrast between Agile Testing and development, and traditional vs. Agile approach.

What is Agile Testing?

  • In the world of software development, there are two very common terminologies, Developers (programmers) and testers. When we hear programmer we think of a person whose main task is to write production code. And when you hear tester you think of a person whose main task in testing and quality assurance.
  • In Agile no one has only one task to perform, here everyone works on it with one aim in the mind that is to deliver the quality their customers need. In a traditional approach, this would have been the primary concern of the tester or the QA of the team. But in Agile even the development team tries to deliver quality end product to the customer.
  • Agile is an iterative development methodology, where requirements evolve through collaboration between the customer and self-organizing teams. Agile aligns development with customer needs. Several core practices used by agile teams relate to testing.
  • Test-driven development (TDD) is used for the development of the services. Where the programmer writes the tiny piece of test which fails. Then tries to write the code around it to make the test pass. It is an approach that many teams follows as it is a smart technique to avoid any bugs.

ROLES AND ACTIVITIES ON AN AGILE TEAM

The roles are divided into mainly two teams:

  • Customer team
  • Developer team
Customer team
  • The customer team comprises business experts, product owners, domain experts, product managers, business analysts, etc. The customer team writes the stories for the development to work on. They provide examples and logic behind the requirements. Their main task is to clear any doubts and give clarification with real world use cases or examples. They are available in each iteration for guiding the Dev and QA teams as well.
  • In a customer team, the testers have a crucial role to play. They help the customers express their requirements as tests.
Developer team
  • The developer team comprises of Developer team includes programmers,system administrators, architects, database administrators, technical writers,security specialists. Each person in the team can be responsible for multiple roles. A developer can also be helping out in testing related activities and a tester could be helping the developers in debugging a issue.
  • Testers are in the developer team as well because testing is one of the core tasks in Agile. Both the testers and the developers help each other in achieving the best quality end product for the customer.

Interaction between Customer and Developer Teams

  • The customer and developer teams work closely together with a common goal to deliver value to the organisation. Testers does not have the sole responsibility for the quality of the product under development. The developer also helps them achieve this by trying to maintain the quality from the first phase of the development.
  • The customer team with developer team prioritise stories which are crucial and are to delivered in each sprint. It’s totally up to the customer that what they want the developer team to work on. They can even request changes in between the sprint and the developer can work on it. If it does not affect the current scope of the story too much. Even if it does they can pick it up in the next upcoming sprint.
  • It is not totally in the hands of the customer team to dictate how much work they want the development team to work on. The developer picks up work according to there bandwidth, estimates it and then starts working on it.
  • Testers have a foot in each world, understanding the customer viewpoint as well as the complexities of the technical implementation. The testers or the QA team acts as a bridge between the customer and the developers. They don’t just understands the customer requirements but also looks at it from a technical viewpoint. and tries to see if it is feasible or not from the developers point of view as well.

**HOW IS AGILE TESTING DIFFERENT? **

  • By now you must be wondering how is Agile testing different from the the other traditional approach? Let’s see how it is like to work on a traditional team vs. an Agile team.

Working on Traditional Teams

  • In traditional team or approach the testers are not involved with developers from the starting phases of the software. Testers are involved in the last phases of the development where they get very little time to test the services on which the developers works for months.
  • Each release cycle is for around 6 months where all the tasks are to be completed and released to the customer. Testers are involved in release planning and requirements definition.But after that they are involved in the end with rushed testing phase and sometimes a delayed release as well.
  • The quality is the sole responsibility of the QA team only. If any of the requirements were missing or any other issue was found the testers were responsible. They didn’t even have the control over if the developer has even tested there code or not.
  • The testers have the power to stop or postpone the release of they find any major issues in the release or if it is not according to the requirements.
  • 6 months seems like a very long time but is not as even after this time the end result is not according to the customers expectations. Things gets deviated from the path and the end result is not covering all the requirements.
  • The testers create there test plans according to the API specs but if the end product is not according to the defined requirements then the whole test plan simply fails.

#agile #api testing #integration testing #quality assurance (qa) #scaled agile #scrum #testing #unit testing #agile teams #agile transformation #test automation

Dejah  Reinger

Dejah Reinger

1599859380

How to Do API Testing?

Nowadays API testing is an integral part of testing. There are a lot of tools like postman, insomnia, etc. There are many articles that ask what is API, What is API testing, but the problem is How to do API testing? What I need to validate.

Note: In this article, I am going to use postman assertions for all the examples since it is the most popular tool. But this article is not intended only for the postman tool.

Let’s directly jump to the topic.

Let’s consider you have an API endpoint example http://dzone.com/getuserDetails/{{username}} when you send the get request to that URL it returns the JSON response.

My API endpoint is http://dzone.com/getuserDetails/{{username}}

The response is in JSON format like below

JSON

{
  "jobTitle": "string",
  "userid": "string",
  "phoneNumber": "string",
  "password": "string",
  "email": "user@example.com",
  "firstName": "string",
  "lastName": "string",
  "userName": "string",
  "country": "string",
  "region": "string",
  "city": "string",
  "department": "string",
  "userType": 0
}

In the JSON we can see there are properties and associated values.

Now, For example, if we need details of the user with the username ‘ganeshhegde’ we need to send a **GET **request to **http://dzone.com/getuserDetails/ganeshhegde **

dzone.com

Now there are two scenarios.

1. Valid Usecase: User is available in the database and it returns user details with status code 200

2. Invalid Usecase: User is Unavailable/Invalid user in this case it returns status with code 404 with not found message.

#tutorial #performance #api #test automation #api testing #testing and qa #application programming interface #testing as a service #testing tutorial #api test

Aurelie  Block

Aurelie Block

1598916060

Top 10 Automation Testing Tools: 2020 Edition

The demand for delivering quality software faster — or “Quality at Speed” — requires organizations to search for solutions in Agile, continuous integration (CI), and DevOps methodologies. Test automation is an essential part of these aspects. The latest World Quality Report 2018–2019 suggests that test automation is the biggest bottleneck to deliver “Quality at Speed,” as it is an enabler of successful Agile and DevOps adoption.

Test automation cannot be realized without good tools; as they determine how automation is performed and whether the benefits of automation can be delivered. Test automation tools is a crucial component in the DevOps toolchain. The current test automation trends have increased in applying artificial intelligence and machine learning (AI/ML) to offer advanced capabilities for test optimization, intelligent test generation, execution, and reporting. It will be worthwhile to understand which tools are best poised to take advantage of these trends.****

#automation-testing #automation-testing-tools #testing #testing-tools #selenium #open-source #test-automation #automated-testing