React Testing Library encourages tests that utilize ________, which means your tests will focus on the end-user perspective rather than implementation details.

  • shallow rendering
  • component snapshots
  • unit testing
  • user interactions
React Testing Library encourages tests that utilize "user interactions." This means that your tests should focus on simulating and testing user interactions with your components. By doing so, you ensure that your tests mimic how a real user would interact with your application, promoting a more realistic and user-centric testing approach. The other options do not represent the primary focus of React Testing Library.

You're building a React component that should accept props of different shapes based on a type prop. Which TypeScript feature would be most appropriate to handle this?

  • Conditional Types
  • Intersection Types
  • Type Assertions
  • Union Types
When dealing with React components that accept different props based on a type prop, Union Types are typically the most appropriate TypeScript feature. Union Types allow you to define a prop type that can accept multiple different shapes, providing flexibility in prop definitions based on the type prop value. Conditional Types, Intersection Types, and Type Assertions serve different purposes and are not as suitable for this scenario.

Your React application uses Apollo Client to fetch data from a GraphQL server. Users have reported seeing outdated data. Which Apollo Client method can you use to forcefully refetch data and bypass the cached results?

  • client.clearCache()
  • client.forceFetch()
  • client.invalidateQuery()
  • client.refetchQuery()
To forcefully refetch data from a GraphQL server and bypass the cached results in Apollo Client, you should use 'client.forceFetch()'. This method makes a fresh request to the server, ensuring that you get the latest data, even if it's already in the cache. 'client.refetchQuery()' is not a standard Apollo Client method, and 'client.invalidateQuery()' and 'client.clearCache()' have different purposes.

What is the main advantage of using React Fragments over wrapping multiple elements in a div?

  • Fragments allow for conditional rendering.
  • Fragments automatically add unique keys to child elements.
  • Fragments improve rendering performance.
  • Fragments provide more styling options.
The main advantage of using React Fragments over wrapping multiple elements in a div is improved rendering performance. Fragments don't add extra nodes to the DOM, which can lead to better performance, especially when dealing with a large number of elements. They don't introduce extra nesting levels, making it an ideal choice for cleaner, more efficient rendering.

A colleague is having trouble rendering a dynamic value in their JSX code. They've tried using quotes, but the value renders as a string. What advice would you give?

  • Advise them to use quotes but ensure the value is parsed as a number or boolean if needed.
  • Encourage them to use double curly braces {{}} around the value.
  • Recommend using backticks (`) to enclose the value.
  • Suggest wrapping the value with single curly braces {}.
To render a dynamic value in JSX as the intended value (rather than as a string), it's essential to wrap the value in single curly braces {}. Double curly braces {{}} are used for expressions or variable interpolation within JSX. Backticks (`) are used for template literals and are not appropriate for this case. Using quotes alone will indeed render the value as a string, so the correct approach is to use single curly braces.

In GraphQL, when you want to get real-time data updates, you would use a ________ instead of a regular query.

  • Live Query
  • Reactive Query
  • Real-time Query
  • Subscription Query
In GraphQL, when you want to receive real-time data updates, you would use a "Subscription Query" instead of a regular query. Subscriptions allow you to subscribe to specific events or data changes and receive updates when those events occur. Regular queries are used for retrieving static data, whereas subscriptions are designed for handling real-time data streams.

If you want to navigate between different screens in a React Native application, which library/package is commonly used?

  • React Native Navigation
  • React Native Router
  • React Navigation
  • React Router Native
In the context of React Native, the commonly used library for navigating between different screens in an application is "React Navigation." React Navigation provides a comprehensive navigation solution for React Native apps, offering features like stack navigation, tab navigation, and drawer navigation, making it a popular choice among developers for handling navigation within their apps.

How can you achieve the behavior of componentDidUpdate in functional components?

  • Functional components cannot achieve this behavior.
  • Use the componentDidMount hook.
  • Use the useEffect hook with dependency array.
  • Use the useEffect hook without a dependency array.
You can achieve the behavior of componentDidUpdate in functional components by using the useEffect hook with a dependency array. This allows you to perform side effects after the component has rendered and when specific dependencies change. It is the functional equivalent of componentDidUpdate in class components and is used for handling updates and side effects.

In your React application, you want to prevent users who are not logged in from accessing certain routes. How would you implement this using React Router?

  • Use the PrivateRoute pattern
  • Use React.auth middleware
  • Use a beforeEnter guard function
  • Use React.AccessControl component
To restrict access to certain routes for non-logged-in users in a React application, you would typically implement the PrivateRoute pattern. This involves creating a custom route component that checks the user's authentication status and redirects them if necessary. The other options are not standard practices for implementing route-based access control.

Libraries like Immer help in managing state by allowing developers to work with a ________ version of the state.

  • Dynamic
  • Immutable
  • Mutable
  • Static
Libraries like Immer enable developers to work with an "Immutable" version of the state. Immutability ensures that the state cannot be changed after it is created, making it easier to track changes and manage state in complex applications. This is a fundamental concept in state management in Redux and many other libraries.