How To Do Test-Driven Development In AngularJS?

Software Testing is essential to verify and double-check the software application produced. Software Testing ensures debugging, reducing development costs, and improvising the software performance.

QA Automation Testing is usually carried out for a successful run-through of the software developed and gives the exact desired output. Automation isn’t just about automating testing; it’s also about having a focus and path to report, clean test data, and set up and demolish various environments.


“Test-Driven Development” describes a programming style in which three activities are closely intertwined: coding, testing (in the form of unit tests), and design (in the form of refactoring).

It is done in the following way:

– Write a “unique” unit test that describes an aspect of the program.

-Execute the test that should fail because the program lacks this function.

-Write “sufficient” code, which is  easy to pass.

– Test “refactor” the code until it meets the simplicity criteria.

– Repeat, “accumulate” unit tests over time.

Expected benefits

Many teams report significant reductions in error rates at the expense of a modest increase in the development effort. Although empirical research has not yet confirmed this, experienced practitioners report that TDD leads to an improvement in design qualities in code and, more generally, at level it is higher in “internal” or technical quality, for example, improving cohesion and coupling metrics.



What is Test-Driven Development in Angular?

Test-Driven Development means that you first write your test, see that it fails, and then write the code that will make it pass. This is also known as the red-green approach. Simply put, it relies on development through testing.

AngularJS is a highly used web framework nowadays. To test Angular properly, you must be familiar with various libraries, many from the Angular team itself. It should work with all the trial frames you need: Mocha, Chai, Transporter, Karma, and more.

Angular was designed for testing purposes. The framework enables server-side request simulation and Document Object Model (DOM) abstraction and thus provides an environment for testing numerous scenarios.

Angular’s dependency injection allows it to simulate and test each component in different areas. Angular Mock is an angular module being used to simulate components that are already existing in the application.

Adding multiple components to your Angular application makes unit testing services available. Angular Mocks can be the middleman between your application’s Angular components and the unit test environment.


How to do test-driven development in AngularJS?

The TDD flow consists of 5 steps:

  • Reading, understanding, and processing the feature or error request.
  • Convert the requirement by scripting test
  • Write and implement code that meets the requirement.
  • Refactoring your code.
  • Rinse, lather and repeat.


Install packages

Once you are in the directory, start configuring your project dependencies. First, initialize the package.json

file. Set up your test environment using a & # 40; configuration file. karma.conf.js & # 41; This is similar to configuring package.json.


 Running your tests

To run your tests, you can run the npm test command in the terminal.



The writing tests deal with events and their expected results. Whenever you start writing tests for your application, you should always think about the results you want from your application’s component suite process.



The injection is an essential feature of angular application unit testing. The injection function characterizes it.

The injection allows the Angular modules $ service, $ controller, $ filter, $ directive, $ factory.

 Test policies

Policies differ in the purpose and structure of services and controllers. Therefore, they are tried with different approaches. The directives have their own encapsulated scope that pulls their data from an external scope, a controller.  To test them correctly, we need to simulate the same process and see if we get the results we want.


Testing Promises

Promises are the standard tool for managing client-server communications. Angular services like ngResource and $ HTTP use the promise to interact with the backend service.


Test events

Events can be generated with $ broadcast and intercepted with $ on. A service that is sent when a new item is added. We test if the event is broadcast if a handler intercepts it, and if its content matches the broadcast content.


 Directory and pattern structure

  • Describe the specification with a type and name.
  • Load the object module.
  • Load simulated modules if necessary.
  • Inject dependencies and spy methods.

Author BIO

Kamal Singh is a Digital Marketing strategist at Devstringx, a top AngularJS development company. He has 5+ years of experience in the information technology industry that inspire him to share his knowledge through articles. He also works with a team of experienced creative digital marketing strategists to generate unique and data-driven campaigns. He is an expert to analyze business USP and implement effective digital marketing initiatives.

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