React-Redux-Form nested component testing - reactjs

I am using React-Redux-Form and React-Bootstrap on client side of application.
I'm stuck on how to testing my components. I have made a small project on github with one of my components named LoginModal:
https://github.com/DmitryIvanovIAMM/react-redux-form-login-test/blob/master/src/tests/Foo-test.js.
To start testing, I am following this tutorial https://www.codementor.io/vijayst/unit-testing-react-components-jest-or-enzyme-du1087lh8.
But when I try to .find() button in my rendered component, the result is an array of length zero. So I can't simulate its behaviour. I try find it (button) several different way but unsuccessful. Please, your suggestion.

This issue is with the rendering of Modal component that is part of #react-bootstrap. There is a discussion about it on https://github.com/react-bootstrap/react-bootstrap/issues/876.
The alternative is to use ReactModal from react-modal. Testing it is described on http://remarkablemark.org/blog/2017/05/17/testing-react-modal/

Related

Initial load time is slow for a react app

I am creating a web app with React which has a form component, uses Formik field and Yup schema for validation. I am also using Redux to capture some form input to render some other component. Everything works ok, but the initial render time is too slow. But once loaded it works fine and 2nd, 3rd refresh is correct very little render time. I am using create react app.
What is the solution? What should I look for? Chrome Dev Tools saying long function chain is main problem. I don't know where is this chain.
Sincerely,
I am out of clue here, component composition and image optimization is key, it is being said in multiple blogs, but not sure in this case.

How to pass data from stencil component to other component in react

I have created one search component using stencil and I'm integrating this stencil codebase with my react application via cdn link. I'm displaying the search component(which was created in stencil) as below in my react codebase :
<custom-search placeholder="Search"></custom-search>
The search component contains a search icon. I need to pass the text in search input field to my react code on click of this icon. How can this be achieved?
Unfortunately I haven't integrate Stencil JS component with React, but passing string data to web component should be working without too much hassle. Do you know if your React app can properly recognize your custom-search component? If not, then you might want to take a look at a link to Stencil JS official document of integrating Stencil JS component to React and make sure component get properly loaded and integrated.
If you know for sure you load the component then not sure why your placeholder is not set within your component - it is just a string after all. Maybe post the custom-search component code, as there might be issue with that (i.e. component lifecycle event you are using might not be doing what you expect to do)
Could you clarify the actual problem, please? :)
Does the component not get rendered, or are you unable to achieve communication from custom-search to the React app?
If the latter is the case, you might want to implement a Custom Event on the Stencil component, to communicate changes back to the consuming app.
As #tomokat mentioned, you should follow the official Stencil React integration docs. This is required, since React cannot handle Custom Events natively, and requires some help from the dev.
Edit: Sorry, I got confused by the first answer. Your title is quite clear, though. If you can show some example code of the component and the React integration, we could probably help in a better way.

How to Create a React Component in Isolation?

I need to create a popup message component which gets user feedback. Is there any way for me to develop a component like this (some type of dialog/modal probably) without making a new page to test it on?
Like, is there any way for me to develop this individual popup message, or other small components, in isolation, and then later attach them to a larger page component?
Sure you could use an online editor like codesandbox
Or you could use a dedicated create react app for testing / developing a component alone
You can just make the popup component, and add it into your App.js to see if it works as far as working on local workspace goes. you can also try some sort of virtual code editor like codepen, stackblitz, codesandbox, etc, then copy the code over into your workspace.

Tabulator: React formater: need 'dispose' handler for a correct implementation

react-tabulator is a library providing an integration of Tabulator in React. Their solution to render a React component within a Tabulator formater uses this function. However, I don't think this is 100% correct, because based on the React doc on integrating React w/ plain JS, ReactDOM.unmountComponentAtNode() needs to be called on dispose in order to to some cleanup. I also communicated this to the author within a GitHub issue, and maybe he'll provide additional info.
My question: is there a hook/handler/way to receive notifications when a cell is being disposed? 1) This will allow me to call the mentioned method, so that React can do some cleanup. 2) This opens also the path towards an alternative approach, leveraging React portals.
Thank you in advance!
I have created an implementation using portals in this gist. It's a Storybook pages. I'm using semantic-ui-react in my project, so a copy/paste of the file may need adapting.
I don't know if it's OK to have thousands of portals. I.e. one per cell. Also, I didn't see any action do "dispose" a portal. I hope that disposing the DOM element where the portal was rendered suffices. Otherwise => memory leaks possible I think.

Issue with UI event when rendering component inside a web component shadow DOM

I'm facing some issues when rendering a React component into the shadow DOM of a webcomponent.
I wrote a small piece of code to turn a React component into a webcomponent, but I want to render the
React component inside the shadow DOM of the webcomponent. But in that case, it seems that React is not able to catch UI events (click, keyPress, etc ...) anymore.
Let's take an example, let say that I have a first webcomponent <awesome-timer /> that render the React component inside the webcomponent node, and another webcomponent <less-awesome-timer /> that render the React component inside the shadow DOM of the webcomponent.
Both webcomponents use the same React component. However the one rendered inside the shadow DOM does not work, because click events on the button of the timer component does not trigger the bound function.
I guess React is not designed to handle such case, but I'd love to get more details about it.
The code of the example is available here : https://gist.github.com/mathieuancelin/cca14d31184bf4468bc1
Does anyone have an idea about it ?
I know this is kinda late but, I believe your issue when you pass any attributes to a web component they instantly become strings Because that's all you can pass to a web component. Now of course you can convert or cast them back to there original data type, except functions because once stringified they loose there scoping, lexical and all.
Now to your main question, you are were trying to pass you child element through the Main web components slot. Now you have to remember that once you pass anything to a web component you now have to use the webs components methods and return types to manage whatever you pass. So yes passing react into a web component will not work they you expect.
You will need to go back to whatever tool you use to build your web component and deal with the slot logic there. Since this is a very old post as are web components. You might not have had access to the modern web component build tool's we have today. I found Stenicl allows you to build and manage your web components in Typescript.
A good option is to change your pattern a little bit and just return web components from your react app.
Or you can use another really cool to call Lit-HTML or Lit-element. I believe they may have combined there core libraries. Anyway these tool will allow you to combine Reactjs and web components where lit-html gives you access to methods simial to Reactjs's life cycle methods. Anyway some good stuff to check out if your stuck at this point.

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