How does ESLint's --fix option handle issues that it can't automatically fix?
- ESLint raises an error and stops
- It logs the issues without attempting to fix them
- It automatically disables the rule causing the issue
- It leaves the issues as is
When ESLint's --fix option encounters issues it can't automatically fix, it will disable the rule causing the issue to prevent further errors. This allows ESLint to continue running and fix as many issues as possible without breaking. The other options do not accurately describe how --fix behaves.
How can you ensure that your project’s dependencies are secure and up-to-date?
- Ignore dependency updates to maintain stability.
- Regularly review and update dependencies using a tool like npm audit or yarn audit.
- Rely on the package maintainers to keep dependencies secure.
- Never update dependencies to avoid breaking changes.
To ensure that your project's dependencies are secure and up-to-date, you should regularly review and update them using tools like npm audit or yarn audit. These tools help identify and address security vulnerabilities. Ignoring updates may lead to security risks, and relying solely on package maintainers is not a recommended practice. Avoiding updates altogether is not a solution as it can lead to outdated and potentially insecure dependencies.
You are developing a critical system where the cost of failure is very high. How would you design your testing strategy to ensure the reliability and stability of the system?
- Conduct extensive Unit Testing
- Rely on Beta Testing by end-users
- Implement Continuous Integration and Continuous Deployment (CI/CD) pipelines
- Perform thorough Regression Testing and use Automated Testing
To ensure the reliability and stability of a critical system, thorough Regression Testing and the use of Automated Testing are essential. These techniques help catch potential issues early and maintain system stability. Extensive Unit Testing alone may not cover all scenarios, and Beta Testing may be too risky for critical systems. CI/CD pipelines support automation but should be combined with robust testing.
You are optimizing the performance of a web application that uses EJS for rendering views. The views have a lot of dynamic content and are currently slow to render. How would you approach optimizing the rendering performance of the EJS templates?
- Implement caching mechanisms for frequently accessed templates using a caching library like Redis.
- Minimize the use of JavaScript in templates and offload complex logic to the server-side to reduce client-side rendering time.
- Precompile EJS templates into JavaScript functions to reduce runtime rendering overhead.
- Increase the client-side rendering capabilities by using a JavaScript framework like React or Angular.
To optimize the rendering performance of EJS templates, one effective approach is to precompile EJS templates into JavaScript functions. This reduces the runtime rendering overhead and improves the efficiency of rendering dynamic content.
In Jest, to isolate a module from its dependencies for more focused unit testing, you would use ______.
- mock
- stub
- spy
- inject
In Jest, you can use the mock function to isolate a module from its dependencies. This allows you to replace the real dependencies with mock implementations for focused unit testing.
In JavaScript, a closure is created when an inner function accesses the ________ of an outer function after the outer function has executed.
- parameters
- variables
- methods
- properties
In JavaScript, a closure is created when an inner function accesses the variables of an outer function after the outer function has executed. Closures allow inner functions to "remember" and access the variables of their containing (outer) function even after the outer function has finished executing. This is a fundamental concept for managing scope and data privacy in JavaScript.
In Pug, to extend a layout, you use the extends keyword and to fill a block within the layout, you use the ______ keyword.
- include
- fill
- block
- insert
In Pug, the extends keyword is used to extend a layout, and the block keyword is used to fill a block within the layout. This allows you to create modular and reusable templates. The other options do not serve the same purpose in Pug.
How does JavaScript's dynamic typing affect variable assignments and operations?
- It enforces strict type checking.
- It allows variables to change type during runtime.
- It requires explicit type annotations for all variables.
- It prevents type errors at compile time.
JavaScript's dynamic typing allows variables to change their data type during runtime. Unlike languages with static typing, you don't need to specify the data type of a variable explicitly.
What is the significance of the call(), apply(), and bind() methods in JavaScript functions?
- They are used for declaring global variables.
- They enable asynchronous execution of functions.
- They manipulate the DOM.
- They facilitate the manipulation of function context and parameter passing.
call(), apply(), and bind() are methods in JavaScript used to manipulate the context in which a function is executed and to pass arguments to functions. They are commonly used in scenarios like setting the value of 'this' in a function and passing arguments dynamically. None of the other options correctly describe their purpose.
You are developing a real-time analytics dashboard that requires aggregation of data from multiple tables. How can you optimize the queries to ensure minimum latency in displaying the results?
- Use caching mechanisms
- Opt for synchronous queries to ensure real-time data
- Optimize database indexes
- Use a single table to store all data
To ensure minimum latency in a real-time analytics dashboard, using caching mechanisms is essential. Caching can store frequently used aggregated data and serve it quickly, reducing the need for complex queries. Options B and D do not align with best practices for real-time analytics. Option C is a good practice but not as directly related to real-time performance as caching.