I'm trying to run tests with component connected to redux and formik. I've been testing several ways to get the result of getting submitted and checking in the state if there was indeed the addition, but all attempts were invalid ... Could anyone give me a try on redux test?
projetct: https://github.com/henriqueweiand/reactjs-crud-state-test/blob/master/src/pages/tests/formDocumentos.test.js
If the component use connect you should wrap the component in a test with Provider to allow the component to use store values.
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When I run my jest tests, I got the following error , this particularly happens with the redux connected components and forwardRef:true is one parameters of the connect wrapper component
enter image description here
How can I fix my jest configuration to prevent this?
You may need to do some cleanup in the after hook for each test. You might also consider whether its appropriate to provide a mock for the redux store, so that you are isolating the component tests from the reducer tests.
Project that I'm working on is written in such pattern: each component has index.js with redux mappings and page.js which accepts mappings via props and renders a view.
Component can be huge, it can contain long chains of other smaller components.
Imagine how each component in the chain accepts around 30 props - redux data and redux actions - and then pass them into other components via chain, other components pass them into another components.
Though it's very typical redux situation, I can't live with it and trying to avoid it all the time. I'm trying to use useSelector and useDispatch to work with store, instead of passing dozens of properties I add useSelector right in the place where data is needed.
And all seems to be fine except tests.
I wrote utils for test to mount components inside redux Provider, utils to easily mutate store and to check history of dispatch.
But tests feels more complicated now then before when they just passed props.
It feels that I'm the only person who tries to write tests using redux store.
Is it good idea or bad? Do you know some articles of how to use useSelector and useDispatch and write tests at the same time?
For testability, look into the Container & Presentation Component Pattern. What you basically do is create a component that is purely presentational and maintains next to no state. Everything it displays, it'll get via props. This will let you test the visual elements without worrying about the store.
Next, create a container component that does all of the redux stuff, e.g., fetches, dispatches, etc. and it'll pass the relevant state as props to the presentational component. This will keep your test file size in check and allow you to focus your tests towards different goals while keeping them much simpler. So, your directory will look something like,
coolComponent
coolComponent.js (presentational component)
coolComponent.test.js
index.js (container component)
index.test.js
Testing the store is important as the store and redux determines your data flow. If your data flow doesn't work, it doesn't matter if you have 1000 tests passing elsewhere. You app will fail.
Keep in mind when testing the components that sometimes it doesn't make sense to test the components on their own. If they're only ever used with a parent, I think you can get good coverage testing them with the parent, so don't double your efforts going overboard with testing that way.
I'm trying to differentiate different redux state changes and saw this github solution: Redux-watch In order to the watch function you're supposed to provide the redux store which can't figure out how to do. I'm passing the store down to this component through a provider for reference.
If you need access to the store state in a component, you should be using the useSelector hook or the connect higher-order component. Don't try to set up store subscriptions yourself in components - React-Redux does that for you already.
I'm building an app as my first real foray into React, Relay and GraphQL, using Relay Modern.
The basic case is, I have a login form component that doesn't really need any data; that is to say, the component renders a form, and has a corresponding mutation, but doesn't need to query anything.
It seems that providing a Relay style query fragment is a necessity when calling createFragmentContainer, which in turn ensures that the this.props.relay will not be null in the context of the component.
Right now, I'm using a standard (non-Relay) React component for the login form, but as a result I'm unable to access the Relay environment to pass it through to the mutation.
My question - is there a way to essentially pass an "empty" Relay fragment? Or is there some better idiom that is recommended in this case?
You actually just use a normal component then create a mutation file with the mutation in it. Run the relay compiler to create the graphql fragment for the mutation and then call on the mutation in the form submit. The mutation does need your environment. Here is the relay modern docs:
https://facebook.github.io/relay/docs/mutations.html
You will need to store the result of the mutation somewhere and then append the auth token to your next requests, but that shouldn't be terribly hard to do. Just onCompleted and store the result somewhere.
Your environment should be a seperate file that you import for mutations and query renders. Only paginationContainer inherits encironment from a queryRenderer.
Redux's Provider component and connect function provide a reference to the store's state to wrapped components via mapStateToProps. As mentioned in the lovely article How to Build a Redux, this is done so that you don't need to refer to a global store object or pass data endlessly down the DOM.
This has a great advantage: the store state is DOM agnostic. You can put any two elements anywhere on the page and provide them with any data you want from the store. If you have a form for customer search and a list of customer search results... the relationship of these presentational elements doesn't affect their access to data.
As far as I can tell, Apollo-react's ApolloProvider does not subscribe to this principle. When I wrap a component with a query using graphql, the results of that query are provided as props to the wrapped component. If those results are needed elsewhere in the app, they must be passed manually or stored on a global reference. In particular, props returned from a graphql query cannot be passed up the DOM.
Is there a way of making ApolloProvider "provide" query results to the rest of the app in the same way redux's Provider does? Do I need to build this functionality myself? Or, better yet, am I misunderstanding something?
Apollo uses Redux to cache the graphql query results. Essentially if you have multiple components that need the same data, just use Apollo to wrap each of them with the same graphql query. You can even go as far as defining the graphql connector once, and using that same connector to wrap your N components.