Categories: Software Development

Django Unit Testing with Mocks

Here I’m going to talk about how to use mocks when writing unit tests for Django, the Python-based web framework. Using Django test mocks has really opened my eyes on how to write much better unit tests. Previously, and in some cases still do when using 3rd party services, I would use fake API servers to serve fake data for testing end to end. With the mock library, I can easily mock out server responses in Django tests.
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Categories: AngularJS, Web Dev Training

Unit Testing in AngularJS

The modern way of development is to build and deliver web apps that include automated unit test suites. These automated tests exercise your web app to make sure that it works and doesn’t have any bugs. Tests give you the confident to say to your client or project manager or customer, yes we have the right features and yes they all work.

“Test-driven development is a set of techniques that any software engineer can follow, which encourages simple design and test suites that inspire confidence…following these two simple rules can lead us to work much more closely to our potential.

  • Write a failing automated test before you write any code.
  • Remove duplication.”

Kent Beck, Test Driven Development

Unit Tests

Unit testing is essential and of course, AngularJS lets you do some unit testing. In fact, it was built from the ground-up to co-operate with unit testing by using dependency injection.

One of the better tutorials on fully testing your AngularJS app is Full-Spectrum Testing With AngularJS and Karma.

To begin unit testing AngularJS, you need the following:

  • Karma test runner
  • Jasmine or Mocha/Chai test frameworks
  • Sinon for mocking/spies/stubs

The Karma test runner will run whatever tests you have. The Jasmine test framework lets you define tests and has assertions (such as myValue.is.expected.toBe(3)). Personally, I prefer the Mocha framework since it only defines tests, and lets you use whatever assertion library you want to use such as Chai, it also has lots of nice features.

A classic on unit testing is Test Driven Development: By Example, it’s by Kent Beck who was one of the founders of the Extreme Programming movement.

Mocking Dependencies for Integration and Unit Testing AngularJS

Sometimes when you’re writing a test, you want to make sure that your service or provider is making the right calls to another service. The way to do this is with mocks. Mocks are fake objects that keep track of which methods were called on them.

Mocks are not essential for writing tests, but there are cases where they do help. When you’re writing a controller that connects to your web app’s REST API, you want to make sure that it calls methodX and methodY. By creating a mock service and registering it with AngularJS, you can write a unit test that makes sure those two methods have been called. When using external 3rd party REST APIs, you may want to mock the $httpBackend to make sure the right calls are being made and the correct responses are returned.

Sinon is valuable for defining mocks. It lets you create method stubs and it lets you spy on method calls.

ng-modules

Find more modules on ngmodules.org

News

AngularJS Meetups

Categories: AngularJS, Software Development, Web Dev Training

AngularJS: testing services that use $resource

In this article we discuss one aspect of AngularJS testing, namely how to unit test code that uses $resource.

When working on a project that uses ngResource (imported into the code as $resource), the unit tests related to the service relying on $resource were failing. I jumped in to do a rewrite or to scrap them entirely if necessary.

  1. The Problem: how to test a service that relies on $resource
  2. Unit Tests Vs. Integration Tests
  3. The Solution: break the dependency and test each part separately
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Categories: Linux, Software Development

PHPUnit Essentials Book Review

PHPUnit Essentials would have come in handy while on a recent contracting gig and on all the other PHP projects I’ve worked on. The book is published by Packt Publishing, the last book I bought from them was on AngularJS and it was a great guide whereas as the O’Reilly book on AngularJS was outdated.

Overall the book was a good read and it’s worth getting as both a guide and a reference.
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Alternatives to Acceptance Testing

Alternatives to Acceptance Testing

I like the goal of eliminating defects while you’re writing code rather than fix bugs later on.

When it comes to testing, my goal is to eliminate defects. At least the ones that matter. (Netscape 4.01 users, you’re on your own.) And I’d much rather prevent defects than find and fix them days or weeks later.

I think of defects as coming from four sources: programmer errors, design errors, requirements errors, and systemic errors. When trying to eliminate defects, I look for practices that address these four causes.

He lists some solid methods for preventing defects for each of these classes of errors.

Preventing programming errors is done with test-driven development; unit-tests, focused integration tests and end-to-end integration tests.

Preventing design errors is done by having a simple clean design, incrementally improving the design and architecture and constantly refactoring to ensure it continues to be clean.

Preventing requirements errors:

  • a whole team is required, cross-functional and able to get what they need to finish the project
  • customer examples, using multiple examples can help clarify the general idea of the feature to implement
  • customer review, get the programmers to walk through the new functionality with customer, kinda like the client UAT (User Acceptance Tests) we do at work.
  • push testers to help in the build process rather than relying on them after releases are made. They can work with the customer to figure out requirements or set up automated regression testing (most companies rely on manual regression testing which eats up a lot of time)

This whole article is very good and Mr Shore is an excellent writer. I’d recommend getting his book too, The Art of Agile Development.