Seamless Deno Integration with Modern Frontend Frameworks Quiz

Explore essential concepts of integrating Deno with leading frontend frameworks such as React, Vue, and Svelte. This quiz helps developers assess their understanding of tools, workflows, and configuration best practices in building full-stack applications using Deno and modern frontend technologies.

1. Deno and Module Imports

   Which statement best describes how modules are typically imported in Deno compared to older approaches?

   1. Modules are imported using require syntax exclusively.
   2. Modules require manual installation through a centralized registry.
   3. Modules must be listed in a package.json file before importing.
   4. Modules are imported via relative or absolute URLs, allowing direct network imports.

   Explanation: Deno commonly imports modules using URLs, enabling direct and straightforward access to online resources without a dependency file by default. The other options reference outdated or irrelevant practices: there is no required package.json file, require syntax is not typical in Deno, and Deno doesn't require a centralized registry for most modules.

2. Using TypeScript with Frontend Frameworks in Deno

   When integrating frontend frameworks like React, Vue, or Svelte in a Deno project, why is native TypeScript support advantageous?

   1. Native TypeScript disables linting errors in Deno projects.
   2. Native TypeScript allows code to run without compilation in the browser.
   3. Native TypeScript enforces strict network permissions automatically.
   4. Native TypeScript means TypeScript files can be used directly without external build tools.

   Explanation: Deno natively supports TypeScript, so files can be run and imported directly, removing the need for extra build tools in server-side code. TypeScript does not inherently allow code to run uncompiled in browsers, nor does it enforce network permissions or disable linting errors—those are separate concerns.

3. Frontend Asset Serving

   In a typical Deno setup serving a React, Vue, or Svelte app, how are frontend build assets commonly delivered to the browser?

   1. By embedding all assets in a single JavaScript file sent from the server.
   2. By converting components to plain HTML strings on the client side only.
   3. By serving static files from a directory using Deno’s HTTP capabilities.
   4. By enabling a built-in frontend live reload utility in Deno.

   Explanation: Deno can serve static files such as JavaScript bundles, HTML, and CSS generated by frontend builds via its HTTP server functionality. Assets are not typically embedded into a single script, components aren't converted to HTML solely on the client, and Deno does not include a built-in live reload facility.

4. React Server-Side Rendering (SSR) with Deno

   Why might a developer choose to perform server-side rendering (SSR) of React components with Deno?

   1. To increase page load times by adding additional server work.
   2. To improve SEO and provide faster initial content display to users.
   3. To ensure all components are only rendered on the client.
   4. To bypass the need for any JavaScript on the client side.

   Explanation: Server-side rendering allows initial content to appear quickly and can be crawled by search engines more effectively, which is beneficial for SEO and user experience. SSR does not ensure client-only rendering, nor does it increase page load times on purpose. Client JavaScript is still required for interactivity.

5. Integrating Vue Single File Components (SFC) with Deno

   What must typically happen before deploying Vue single file components (SFCs) with a Deno backend?

   1. SFCs must be compiled into JavaScript using a build tool before deployment.
   2. SFCs are only used if they contain no styles or scripts.
   3. SFCs are directly imported into Deno as plain HTML files.
   4. SFCs can run natively on the backend without compilation.

   Explanation: Vue SFCs combine template, style, and script in one file and require compilation into standard JavaScript, CSS, and HTML for use in browsers and to interact with servers. They cannot run natively in Deno, aren't imported as HTML, and they're not restricted to only simple templates.

6. Svelte and Deno Integration Basics

   When integrating Svelte with Deno in a full-stack project, what is typically true about Svelte components?

   1. Svelte components must be pre-compiled into JavaScript before being served.
   2. Svelte components must be written in plain JavaScript without any templates.
   3. Svelte components can only function in non-TypeScript environments.
   4. Svelte components are executed directly on the server without any compilation.

   Explanation: Svelte requires components to be compiled into efficient JavaScript code before deployment. Components cannot run directly on servers without compilation, they are compatible with TypeScript, and templates are a core feature, not excluded.

7. Setting Up a Deno Backend for a Frontend App

   Which configuration is generally needed to enable a Deno backend to serve a built frontend React, Vue, or Svelte app?

   1. Enabling hot module replacement directly in Deno’s runtime.
   2. Placing the frontend source files in the root project directory without building.
   3. Configuring Deno’s HTTP server to serve static files from the frontend build directory.
   4. Importing all frontend scripts directly into the backend code.

   Explanation: You typically configure an HTTP server in Deno to serve the built static files (like index.html, bundle.js, and styles.css) from the build output directory. Deno doesn't have native hot module replacement, frontend scripts don't get imported into backend code, and unbuilt frontend source files aren't suitable for client delivery.

8. Network Permissions in Deno

   Suppose your Deno backend fetches data for a Vue frontend using an HTTP API. What must be ensured for the fetch operation to succeed?

   1. Data can be fetched only from local JSON files in Deno.
   2. Deno must be granted explicit network permission on execution.
   3. The fetch command must be run in a browser only.
   4. No special permissions are required since network access is unrestricted.

   Explanation: Deno's secure-by-default model requires explicit permission for network access, such as using a command-line flag. Fetch operations in backend code won't run in browsers, network access is not permitted by default, and fetches are not limited to static JSON files.

9. Hot Reloading During Development

   How do developers typically achieve hot reloading for frontend frameworks in a Deno project during development?

   1. By using external development servers or tools that watch for frontend file changes.
   2. By manually refreshing the browser after each code change.
   3. By compiling frontend code directly in the Deno server on the fly.
   4. By relying on a built-in Deno flag for automatic hot reloading of all files.

   Explanation: Most frontend frameworks utilize their own development servers with hot reload features that watch for file changes, separate from Deno’s backend. Deno itself doesn’t have built-in hot reloading for frontend assets, and manual refreshing or compiling on the server are less efficient or non-standard.

10. Environment Variables and Configuration

    When sharing configuration between a Deno backend and a frontend React app, what is the recommended practice?

    1. Expose only non-sensitive variables to the frontend via build-time injection.
    2. Use runtime code to allow the frontend to access all backend configuration.
    3. Directly share private backend environment variables with the frontend.
    4. Ignore environment variables and hardcode all configuration values.

    Explanation: Sensitive data should never be exposed to the frontend; only safe values can be injected at build time. Direct sharing of backend variables is a security risk, runtime sharing can leak sensitive data, and hardcoding configuration removes flexibility and maintainability.