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Discussion on: TDD in Angular - Dependency Injection and Mocking

qarunqb profile image
Bearded JavaScripter Author

Thanks a lot for the clarifications.

With respect to the forms, it's really up to the developers on how they wanna handle the validation. Once you decide that, the unit tests will follow where your validation is.

So for example:

<form action = '/create-user' method = 'POST'>

There really isn't much unit testing that could be done on the front end in terms of validation. An Angular HttpInterceptor can technically still catch the request before it goes off to the server, so it can grab the body and perform validation checks there, but you can also do the validation checks on the server and return the appropriate response based on the form value.

With respect to a ReactiveForms declaration inside a component as follows:

form: FormGroup;

constructor(private fb: FormBuilder) {
  this.form ={
    name: this.fb.control('', Validators.required),
    email: this.fb.control('', [Validators.required,]) 

This form can be unit tested and validated entirely on the client side to ease Validation on the server side. You can find many of the Validators here. And you can even stitch together custom validators to consider weird cases as well. Angular also comes with Sanitization for user input as well, though I have to do some more research on it.

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layzee profile image
Lars Gyrup Brink Nielsen • Edited on


When I tried that, I really didn't know how to start. I first needed to play around with material components, learn how they work, what there interfaces are... So I couldn't really write a Cypress test before because I din't know what HTML element I should select for expectations...

This is one of the issues that component harnesses address. You'd have to implement a HarnessEnvironment for Cypress though.

mapping a backend model (which is returned by an angular service) to a component model that contains all and only the information in appropriate data format that it can be used in templates.

There are many ways to approach this. I prefer creating input properties with data types that are the most convenient for presentational components and then doing mapping either in container components or services used by container components.

We can then easily test the mapping in isolated unit tests and there's less business logic in our presentational components.