Testing Angular with Jasmine and Karma

Our goal

In this tutorial we will be building and testing an employee directory for a fictional company. This directory will have a view to show all of our users along with another view to serve as a profile page for individual users. Within this part of the tutorial we’ll focus on building the service and its tests that will be used for these users.

In following tutorials, we’ll populate the user profile page with an image of the user’s favorite Pokemon using the Pokeapi and learn how to test services that make HTTP requests.

What you should know

The primary focus for this tutorial is testing so my assumption is that you’re comfortable working with TypeScript and Angular applications. As a result of this I won’t be taking the time to explain what a service is and how it’s used. Instead, I’ll provide you with code as we work through our tests.

Why Test?

From personal experience, tests are the best way to prevent software defects. I’ve been on many teams in the past where a small piece of code is updated and the developer manually opens their browser or Postman to verify that it still works. This approach (manual QA) is begging for a disaster.

Tests are the best way to prevent software defects.

As features and codebases grow, manual QA becomes more expensive, time consuming, and error prone. If a feature or function is removed does every developer remember all of its potential side-effects? Are all developers manually testing in the same way? Probably not.

The reason we test our code is to verify that it behaves as we expect it to. As a result of this process you’ll find you have better feature documentation for yourself and other developers as well as a design aid for your APIs.

Why Karma?

Karma is a direct product of the AngularJS team from struggling to test their own framework features with existing tools. As a result of this, they made Karma and have transitioned it to Angular as the default test runner for applications created with the Angular CLI.

In addition to playing nicely with Angular, it also provides flexibility for you to tailor Karma to your workflow. This includes the option to test your code on various browsers and devices such as phones, tablets, and even a PS3 like the YouTube team.

Karma also provides you options to replace Jasmine with other testing frameworks such as Mocha and QUnit or integrate with various continuous integration services like JenkinsTravisCI, or CircleCI.

Unless you add some additional configuration your typical interaction with Karma will be to run ng test in a terminal window.

Why Jasmine?

Jasmine is a behavior-driven development framework for testing JavaScript code that plays very well with Karma. Similar to Karma, it’s also the recommended testing framework within the Angular documentation as it’s setup for you with the Angular CLI. Jasmine is also dependency free and doesn’t require a DOM.

As far as features go, I love that Jasmine has almost everything I need for testing built into it. The most notable example would be spies. A spy allows us to “spy” on a function and track attributes about it such as whether or not it was called, how many times it was called, and with which arguments it was called. With a framework like Mocha, spies are not built-in and would require pairing it with a separate library like Sinon.js.

The good news is that the switching costs between testing frameworks is relatively low with differences in syntax as small as Jasmine’s toEqual() and Mocha’s to.equal().

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Testing Angular with Jasmine and Karma
Roberta  Ward

Roberta Ward

1593144120

Basic Introduction to Unit Testing in Angular

What is Unit Testing?

Unit testing is testing a unit in an isolated environment. A unit can be a class, component, service, directive module, etc. which can be logically separated from the software. Any unit in an app is not isolated, it’s quite normal that it will be depending on the other units in an application for resources like data or methods.

So if we do an integrated test of the application and it fails then it’s hard to identify where exactly the code is breaking. So the purpose of unit testing is to test each unit individually and see if it’s working fine.

Benefits of Unit Testing

Reveal design mistakes

You may encounter difficulty while writing tests which might reveal that the design is not correct and you may be violating some important coding principles. Or after running the test it shows unexpected behavior.

Add new features without breaking anything

If you add any new feature into existing code and after running test passes then you can be confident it won’t break the application.

Simplifies debugging process

As discussed earlier it makes it easy to exactly identify where the code is breaking.

Tests make developers more confident about their work

So, we will understand unit testing in angular by looking at some basic simple examples and then getting to know why and how we have done.

#angular #angular #angular9 #jasmine #karma #testing #unit tesing in angular #unit testing

Angular Unit Testing : Unit Test Angular Component With Service | Karma | Jasmine

Angular Unit Testing : Unit Test Angular Component With Service | Karma | Jasmine

In this video, you’ll learn how to write a unit test case for an Angular component method which is using a service to make asynchronous API calls.

For the written tutorial version you can check the CodeHandbook blog.
https://codehandbook.org/how-to-unit-test-angular-component-with-service/

#angular #karma #jasmine

Christa  Stehr

Christa Stehr

1598940617

Install Angular - Angular Environment Setup Process

Angular is a TypeScript based framework that works in synchronization with HTML, CSS, and JavaScript. To work with angular, domain knowledge of these 3 is required.

  1. Installing Node.js and npm
  2. Installing Angular CLI
  3. Creating workspace
  4. Deploying your First App

In this article, you will get to know about the Angular Environment setup process. After reading this article, you will be able to install, setup, create, and launch your own application in Angular. So let’s start!!!

Angular environment setup

Install Angular in Easy Steps

For Installing Angular on your Machine, there are 2 prerequisites:

  • Node.js
  • npm Package Manager
Node.js

First you need to have Node.js installed as Angular require current, active LTS or maintenance LTS version of Node.js

Download and Install Node.js version suitable for your machine’s operating system.

Npm Package Manager

Angular, Angular CLI and Angular applications are dependent on npm packages. By installing Node.js, you have automatically installed the npm Package manager which will be the base for installing angular in your system. To check the presence of npm client and Angular version check of npm client, run this command:

  1. npm -v

Installing Angular CLI

  • Open Terminal/Command Prompt
  • To install Angular CLI, run the below command:
  1. npm install -g @angular/cli

installing angular CLI

· After executing the command, Angular CLI will get installed within some time. You can check it using the following command

  1. ng --version

Workspace Creation

Now as your Angular CLI is installed, you need to create a workspace to work upon your application. Methods for it are:

  • Using CLI
  • Using Visual Studio Code
1. Using CLI

To create a workspace:

  • Navigate to the desired directory where you want to create your workspace using cd command in the Terminal/Command prompt
  • Then in the directory write this command on your terminal and provide the name of the app which you want to create. In my case I have mentioned DataFlair:
  1. Ng new YourAppName

create angular workspace

  • After running this command, it will prompt you to select from various options about the CSS and other functionalities.

angular CSS options

  • To leave everything to default, simply press the Enter or the Return key.

angular setup

#angular tutorials #angular cli install #angular environment setup #angular version check #download angular #install angular #install angular cli

Roberta  Ward

Roberta Ward

1595344320

Wondering how to upgrade your skills in the pandemic? Here's a simple way you can do it.

Corona Virus Pandemic has brought the world to a standstill.

Countries are on a major lockdown. Schools, colleges, theatres, gym, clubs, and all other public places are shut down, the country’s economy is suffering, human health is on stake, people are losing their jobs and nobody knows how worse it can get.

Since most of the places are on lockdown, and you are working from home or have enough time to nourish your skills, then you should use this time wisely! We always complain that we want some ‘time’ to learn and upgrade our knowledge but don’t get it due to our ‘busy schedules’. So, now is the time to make a ‘list of skills’ and learn and upgrade your skills at home!

And for the technology-loving people like us, Knoldus Techhub has already helped us a lot in doing it in a short span of time!

If you are still not aware of it, don’t worry as Georgia Byng has well said,

“No time is better than the present”

– Georgia Byng, a British children’s writer, illustrator, actress and film producer.

No matter if you are a developer (be it front-end or back-end) or a data scientisttester, or a DevOps person, or, a learner who has a keen interest in technology, Knoldus Techhub has brought it all for you under one common roof.

From technologies like Scala, spark, elastic-search to angular, go, machine learning, it has a total of 20 technologies with some recently added ones i.e. DAML, test automation, snowflake, and ionic.

How to upgrade your skills?

Every technology in Tech-hub has n number of templates. Once you click on any specific technology you’ll be able to see all the templates of that technology. Since these templates are downloadable, you need to provide your email to get the template downloadable link in your mail.

These templates helps you learn the practical implementation of a topic with so much of ease. Using these templates you can learn and kick-start your development in no time.

Apart from your learning, there are some out of the box templates, that can help provide the solution to your business problem that has all the basic dependencies/ implementations already plugged in. Tech hub names these templates as xlr8rs (pronounced as accelerators).

xlr8rs make your development real fast by just adding your core business logic to the template.

If you are looking for a template that’s not available, you can also request a template may be for learning or requesting for a solution to your business problem and tech-hub will connect with you to provide you the solution. Isn’t this helpful 🙂

Confused with which technology to start with?

To keep you updated, the Knoldus tech hub provides you with the information on the most trending technology and the most downloaded templates at present. This you’ll be informed and learn the one that’s most trending.

Since we believe:

“There’s always a scope of improvement“

If you still feel like it isn’t helping you in learning and development, you can provide your feedback in the feedback section in the bottom right corner of the website.

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Angular Unit Testing : Testing Private Methods | Karma | Jasmine

Angular Unit Testing : Testing Private Methods | Karma | Jasmine

In this tutorial, you’ll learn how to unit test private methods using Karma Jasmine in an Angular application. We’ll see three ways to access the private methods while writing unit test case for Angular components.

#angular #karma #jasmine