What do you mean by Event Bubbling and Event Capturing?

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There are two ways for accomplishing event propagation and the order in which an event is received in the HTML DOM API. These are Event Bubbling and Event Capturing. In the former, the event is …

How will you distinguish Redux from Flux?

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Components – React components subscribe to the store in flux whereas in redux, container components utilize connect Dispatcher – There is no dispatcher in redux. On the other hand, flux has a singleton dispatcher Number of Stores …

How to create a TextEditingController in flutter?

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To retrieve the text a user has entered into a text field, create a TextEditingController and supply it to a TextField or TextFormField.

What is the difference between passing an object or a function in setState?

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Passing an update function allows you to access the current state value inside the updater. Since setState calls are batched, this lets you chain updates and ensure they build on top of each other instead of conflicting:

What is the prior art for Hooks?

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Hooks synthesize ideas from several different sources: Our old experiments with functional APIs in the react-future repository. React community’s experiments with render prop APIs, including Ryan Florence’s Reactions Component. Dominic Gannaway’s adopt keyword proposal as a sugar syntax for render props. State …

Jest mockFn.mock.calls function

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An array containing the call arguments of all calls that have been made to this mock function. Each item in the array is an array of arguments that were passed during the call. For example: …

Is there any age limit for taking JEST examination?

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There is no restriction on age for appearing in JEST examination. However, each participating institute has its own eligibility criteria. For details on the eligibility criteria of the participating institutes candidates are advised to visit …

What are the disciplines on which JEST examination is conducted?

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You can appear for the JEST examination in Physics or Theoretical Computer Science but not for both.

How can I test React component’s style with Jest + Enzyme?

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There are a few mistakes in your provided code: You should not be using DOM element’s style property because React does not manage it. Shift the hidden property into the state instead. I believe headerStyle is a shallow copy of the …

Jest fails to transpile import from npm linked module

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I had to change the transformIgnorePatterns configuration option of Jest in the package.json of the web module.

How to test image upload stream with supertest and jest?

Posted by Jennifer | Updated on |


This should work. To pipe data to a request you have to tell the readable stream to pipe to the request. The other way is for receiving data from the server. This also uses done …

React jest test with enzyme error

Posted by Jennifer | Updated on |


Just solved the problem by first installing enzyme-to-json; npm install –save-dev enzyme-to-json imported toJson inside my test_file.js

What are the differences between for…of and for…in statements

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Both for…in and for…of statements iterate over js data structures. The only difference is over what they iterate: for..in iterates over all enumerable property keys of an object for..of iterates over the values of an …

What are the differences between spread operator and rest parameter

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Rest parameter collects all remaining elements into an array. Whereas Spread operator allows iterables( arrays / objects / strings ) to be expanded into single arguments/elements. i.e, Rest parameter is opposite to the spread operator.

What are the differences between arguments object and rest parameter

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There are three main differences between arguments object and rest parameters The arguments object is an array-like but not an array. Whereas the rest parameters are array instances. The arguments object does not support methods …