In Go, the 'switch' keyword is used to start a switch statement, which is a control structure used for executing one of many possible blocks of code based on the value of an expression.

The int8 data type is suitable for representing integer values ranging from -128 to 127. Its memory footprint is smaller compared to other integer types, which helps optimize memory usage in large datasets.

Middleware in a web application refers to software that provides common services and capabilities to applications outside of what鈥檚 offered by the operating system. Rate limiting is a common cross-cutting concern addressed by middleware, ensuring that certain operations do not exceed a predefined rate, preventing abuse or excessive usage.

Authentication middleware in Gorilla Mux can be implemented by creating a custom middleware function that checks the authentication status before handling the request. This function can verify the presence of authentication tokens or session cookies, and reject unauthorized requests. Using built-in middleware or third-party services may not offer the flexibility needed for custom authentication logic.

The 'recover' function in Go is used in conjunction with 'defer' to handle panics gracefully. When called inside a deferred function, 'recover' intercepts a panic and allows the program to regain control, effectively preventing the panic from propagating further. This enables developers to handle exceptional situations and errors in a controlled manner, ensuring that the program can recover from panics without crashing. However, it's important to note that 'recover' only works within deferred functions and is only useful for handling panics; it cannot recover from other types of errors.

In Go, the rune data type is used to represent a Unicode character. It's synonymous with int32 and is commonly used when dealing with Unicode characters or representing the code point of a particular character.

Goroutines are lightweight threads of execution in Go, allowing concurrent execution without the overhead of full-blown threads.

The encoding/json package in Go provides powerful tools for serializing and deserializing JSON data, including support for complex nested structures. By utilizing this package, you can ensure maintainability and efficiency in your code, as it handles the intricacies of JSON serialization and deserialization automatically. This approach minimizes the need for manual implementation, reducing the potential for errors and improving code readability.

The correct option is text/template. The text/template package in Go provides functionality for parsing and executing text templates. It's a powerful package used for creating text-based output formats. It's commonly used in web applications for generating dynamic HTML content and other text-based formats.

In Go, methods can be defined on all data types, not just structs. This includes slices and maps, allowing for more flexible and expressive code when working with various data structures.

GUnit stands out for its features such as test parallelization and subtests, which help in organizing and managing tests efficiently. These capabilities make it a suitable choice for projects requiring extensive test suites.

While code coverage analysis is valuable, it has limitations. It does not guarantee the absence of bugs, as it only measures the extent to which the code has been executed by tests. Additionally, achieving high code coverage can provide a false sense of security, as it does not necessarily indicate thorough testing or the absence of defects. Developers should be aware of these limitations and supplement code coverage analysis with other testing techniques to ensure robust software quality.