The third form of components in reagent can get a constructor key. In the documentation they say you provide a function with 2 arguments, but can you provide a 3 arguments functions with the last one being the possible context?

When you say context, do you mean react context or do you mean an encapsulating closure?

@neo2551 looking at the documentation, it would appear that you can provide an encapsulating clojure by wrapping the form-3 component in a let: https://github.com/reagent-project/reagent/blob/master/doc/CreatingReagentComponents.md#form-3-a-class-with-life-cycle-methods

@goomba I meant a react context

I took a glance through the source code and I don't see anything explicitly mentioned about it. My guess is it's exposed via life-cycle methods if you're already familiar with react, but I'm not a react expert.

does anyone have any ideas how to recursively expand form-2 components for testing?

:thinking_face: actually I'm not sure if that makes sense for unit testing

What are you looking to do @goomba?

testing the hiccup generated by components 🙂

but then I realized that it doesn't make for good unit-testing since once you start dealing with reactions now you're off in side-effect territory

To get you on the right foot, the approach you are looking for is not testing the hiccup generated, but that the component renders to the dom correctly. So my recommendation is checking out how the JavaScript community tests React. The general idea is: 1. Define a component 2. Instantiate the component 3. Render the component 4. assert your component renders/behaves as you expect e.g.

(defn my-comp [] ...) ; define component

(deftest my-comp-renders 
   (let [comp [my-component props]]) ; instantiate component
          container (render comp)] ; render component to a dom element like you would in your app
     ; assert your component renders/behaves as you expect
     )

So my question is, what if you have internal reactions?

Haven't we kind've gotten away from unit testing at that point? If our containers are only prop driven, that's no problem. But if we're using reactions internally then we'd have to set up the ratom state prior to initiating the test, which could get messy

One obvious solution is develop only using props but that's not always practical/performant, depends on the situation

Unit tests are one tool and in this case was serving as a simple example of the basis of how React tests work. I prefer integration testing in general, but it also depends on what I am doing. Right tool for the job 🙂 As for how to test stateful components, that depends on how your state is structured/what you are doing. e.g. is it a screen and we want to test that an API call hydrates the component? or is it a simple component that just happens to track some internal actions like a counter?

Folks, I'm trying to use reagent 0.8.1 with react 16.9 and I'm getting warnings about componentWillMount for lots of my components. It seems that reagent creates componentWillMount implicitly. Do I understand correctly that there is no way to use react 16.9 with the latest reagent without these warnings? If yes, does anybody know if it's planned to release the next version of reagent soon? I see the support for react 16.9 was merged 10 days ago, but there is still no release