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JAVASCRIPTHTMLCSSPYTHONSQLJAVACPPCSHARPPHPTYPESCRIPTCRUBYGOSWIFTKOTLINRUSTRBASHSCALAOBJECTIVE-CDARTPERLLUAMATLABXMLJSONMARKDOWNASSEMBLYLATEXYAMLSOLIDITYBLOCKCHAIN

Topics

Go Basics

Introduction to GoInstalling GoGo SyntaxGo VariablesGo Data TypesGo ConstantsGo OperatorsGo CommentsGo KeywordsGo IdentifiersGo PackagesGo Import StatementGo Main FunctionGo Print Functions

Control Structures

Go If-Else StatementsGo Switch StatementGo For LoopGo RangeGo Break and ContinueGo DeferGo Panic and Recover

Functions

Go Function DeclarationGo Function ParametersGo Return ValuesGo Multiple Return ValuesGo Named Return ValuesGo Variadic FunctionsGo Anonymous FunctionsGo ClosuresGo Recursion

Data Structures

Go ArraysGo SlicesGo MapsGo StructsGo PointersGo Type AssertionsGo Type Switches

Object-Oriented Programming

Go MethodsGo InterfacesGo EmbeddingGo CompositionGo Polymorphism

Concurrency

Go GoroutinesGo ChannelsGo Select StatementGo Buffered ChannelsGo Channel SynchronizationGo Channel DirectionsGo WaitGroupsGo MutexesGo Atomic Operations

Error Handling

Go Error InterfaceGo Creating Custom ErrorsGo Error WrappingGo Error Handling Best Practices

File Handling

Go File OperationsGo Reading FilesGo Writing FilesGo File Permissions

Testing

Go Testing PackageGo Unit TestingGo Benchmark TestingGo Test CoverageGo Table-Driven Tests

Standard Library

Go fmt PackageGo io PackageGo os PackageGo strings PackageGo time PackageGo math PackageGo sort PackageGo encoding/json PackageGo net/http Package

Advanced Topics

Go ReflectionGo ContextGo GenericsGo Memory ManagementGo Garbage CollectionGo Race DetectorGo AssemblyGo cgoGo ProfilingGo Cross-Compilation

Best Practices

Go Code OrganizationGo Error Handling PatternsGo Naming ConventionsGo DocumentationGo Performance OptimizationGo Idiomatic GoGo Project Structure

Tools and Ecosystem

Go ModulesGo WorkspacesGo Command-Line ToolsGo LintersGo FormattersGo Dependency ManagementGo Build TagsGo Generate

Go Error Wrapping

Error wrapping is a crucial feature in Go programming, introduced in Go 1.13. It allows developers to add context to errors while preserving the original error information. This technique enhances error handling and debugging capabilities in Go applications.

Understanding Error Wrapping

Error wrapping builds upon Go's Error Interface, enabling you to create more informative error messages. It's particularly useful when you want to add context to an error as it propagates through different layers of your application.

How to Wrap Errors

To wrap an error, use the fmt.Errorf() function with the %w verb. This verb indicates that you're wrapping the error.


originalErr := errors.New("database connection failed")
wrappedErr := fmt.Errorf("failed to fetch user data: %w", originalErr)

Unwrapping Errors

Go provides the errors.Unwrap() function to retrieve the original error from a wrapped error. This function is useful when you need to access the underlying error.


if errors.Is(wrappedErr, originalErr) {
    fmt.Println("The wrapped error contains the original error")
}

Best Practices for Error Wrapping

  • Use error wrapping to add meaningful context to errors
  • Avoid wrapping errors multiple times unnecessarily
  • Utilize errors.Is() and errors.As() for error checking and type assertions
  • Consider creating custom error types for specific error scenarios

Error Wrapping in Action

Let's look at a more comprehensive example demonstrating error wrapping in a real-world scenario:


func fetchUserData(userID int) error {
    err := queryDatabase(userID)
    if err != nil {
        return fmt.Errorf("failed to fetch user data for ID %d: %w", userID, err)
    }
    return nil
}

func queryDatabase(userID int) error {
    // Simulating a database error
    return errors.New("database connection timeout")
}

func main() {
    err := fetchUserData(123)
    if err != nil {
        fmt.Println(err)
        if errors.Is(err, errors.New("database connection timeout")) {
            fmt.Println("Database issue detected")
        }
    }
}

This example demonstrates how error wrapping can provide valuable context while still allowing for specific error checking.

Conclusion

Error wrapping is a powerful feature in Go that enhances error handling and debugging. By using this technique, you can create more informative and context-rich error messages, leading to improved error management in your Go applications. Remember to combine error wrapping with other Go error handling best practices for robust and maintainable code.