Error handling is an important aspect of any programming language, including Go. Here are some best practices for error handling in Go code:
Return errors as values: In Go, errors are represented as values. Functions should return an error value as a second return value if an error occurs.
Check errors immediately: It's important to check errors immediately after they occur to prevent further execution of the program with invalid state.
Don't panic: The panic function should be used only for unrecoverable errors, such as out-of-memory errors or critical system failures. In general, it's better to return an error value and let the calling code handle it.
Use defer for cleanup: The defer statement can be used to schedule a function call to run after the current function completes, regardless of whether an error occurred or not. This is useful for cleaning up resources like file handles or network connections.
Wrap errors with context: When returning an error, it's often useful to provide additional context about what went wrong. This can be done by wrapping the error with additional information using the fmt.Errorf function or by using a third-party library like github.com/pkg/errors.
Use error codes sparingly: While it's common to use error codes in some languages, Go favors the use of descriptive error messages instead. Error codes can be ambiguous and difficult to maintain over time.
Use panics for unrecoverable errors: As mentioned before, panics should only be used for unrecoverable errors. Panicking can cause the entire program to crash, so it should be avoided unless absolutely necessary.
Overall, the goal of error handling in Go is to provide clear and descriptive error messages to the calling code while also allowing for easy cleanup and recovery.