Feat/golang instructions (#38)

* feat: ✨ Add comprehensive Go development instructions

- Introduced a detailed guide for writing Go code adhering to idiomatic practices.
- Covers general instructions, naming conventions, code style, error handling, and security best practices.
- References established resources like Effective Go and Google's Go Style Guide.

* feat: ✨ Add Go development instructions

- Introduced guidelines for writing Go code that adhere to idiomatic Go practices and community standards.

Author: salihguru

README.md

@@ -32,6 +32,7 @@ Team and project-specific instructions to enhance GitHub Copilot's behavior for
 - [.NET MAUI](instructions/dotnet-maui.instructions.md) - .NET MAUI component and application patterns
 - [Genaiscript](instructions/genaiscript.instructions.md) - AI-powered script generation guidelines
 - [Generate Modern Terraform Code For Azure](instructions/generate-modern-terraform-code-for-azure.instructions.md) - Guidelines for generating modern Terraform code for Azure
+- [Go Development Instructions](instructions/go.instructions.md) - Instructions for writing Go code following idiomatic Go practices and community standards
 - [Guidance for Localization](instructions/localization.instructions.md) - Guidelines for localizing markdown documents
 - [Markdown](instructions/markdown.instructions.md) - Documentation and content creation standards
 - [Next.js + Tailwind Development Instructions](instructions/nextjs-tailwind.instructions.md) - Next.js + Tailwind development standards and instructions

instructions/go.instructions.md

@@ -0,0 +1,292 @@
+---
+description: 'Instructions for writing Go code following idiomatic Go practices and community standards'
+applyTo: '**/*.go,**/go.mod,**/go.sum'
+---
+
+# Go Development Instructions
+
+Follow idiomatic Go practices and community standards when writing Go code. These instructions are based on [Effective Go](https://go.dev/doc/effective_go), [Go Code Review Comments](https://go.dev/wiki/CodeReviewComments), and [Google's Go Style Guide](https://google.github.io/styleguide/go/).
+
+## General Instructions
+
+- Write simple, clear, and idiomatic Go code
+- Favor clarity and simplicity over cleverness
+- Follow the principle of least surprise
+- Keep the happy path left-aligned (minimize indentation)
+- Return early to reduce nesting
+- Make the zero value useful
+- Document exported types, functions, methods, and packages
+- Use Go modules for dependency management
+
+## Naming Conventions
+
+### Packages
+
+- Use lowercase, single-word package names
+- Avoid underscores, hyphens, or mixedCaps
+- Choose names that describe what the package provides, not what it contains
+- Avoid generic names like `util`, `common`, or `base`
+- Package names should be singular, not plural
+
+### Variables and Functions
+
+- Use mixedCaps or MixedCaps (camelCase) rather than underscores
+- Keep names short but descriptive
+- Use single-letter variables only for very short scopes (like loop indices)
+- Exported names start with a capital letter
+- Unexported names start with a lowercase letter
+- Avoid stuttering (e.g., avoid `http.HTTPServer`, prefer `http.Server`)
+
+### Interfaces
+
+- Name interfaces with -er suffix when possible (e.g., `Reader`, `Writer`, `Formatter`)
+- Single-method interfaces should be named after the method (e.g., `Read` → `Reader`)
+- Keep interfaces small and focused
+
+### Constants
+
+- Use MixedCaps for exported constants
+- Use mixedCaps for unexported constants
+- Group related constants using `const` blocks
+- Consider using typed constants for better type safety
+
+## Code Style and Formatting
+
+### Formatting
+
+- Always use `gofmt` to format code
+- Use `goimports` to manage imports automatically
+- Keep line length reasonable (no hard limit, but consider readability)
+- Add blank lines to separate logical groups of code
+
+### Comments
+
+- Write comments in complete sentences
+- Start sentences with the name of the thing being described
+- Package comments should start with "Package [name]"
+- Use line comments (`//`) for most comments
+- Use block comments (`/* */`) sparingly, mainly for package documentation
+- Document why, not what, unless the what is complex
+
+### Error Handling
+
+- Check errors immediately after the function call
+- Don't ignore errors using `_` unless you have a good reason (document why)
+- Wrap errors with context using `fmt.Errorf` with `%w` verb
+- Create custom error types when you need to check for specific errors
+- Place error returns as the last return value
+- Name error variables `err`
+- Keep error messages lowercase and don't end with punctuation
+
+## Architecture and Project Structure
+
+### Package Organization
+
+- Follow standard Go project layout conventions
+- Keep `main` packages in `cmd/` directory
+- Put reusable packages in `pkg/` or `internal/`
+- Use `internal/` for packages that shouldn't be imported by external projects
+- Group related functionality into packages
+- Avoid circular dependencies
+
+### Dependency Management
+
+- Use Go modules (`go.mod` and `go.sum`)
+- Keep dependencies minimal
+- Regularly update dependencies for security patches
+- Use `go mod tidy` to clean up unused dependencies
+- Vendor dependencies only when necessary
+
+## Type Safety and Language Features
+
+### Type Definitions
+
+- Define types to add meaning and type safety
+- Use struct tags for JSON, XML, database mappings
+- Prefer explicit type conversions
+- Use type assertions carefully and check the second return value
+
+### Pointers vs Values
+
+- Use pointers for large structs or when you need to modify the receiver
+- Use values for small structs and when immutability is desired
+- Be consistent within a type's method set
+- Consider the zero value when choosing pointer vs value receivers
+
+### Interfaces and Composition
+
+- Accept interfaces, return concrete types
+- Keep interfaces small (1-3 methods is ideal)
+- Use embedding for composition
+- Define interfaces close to where they're used, not where they're implemented
+- Don't export interfaces unless necessary
+
+## Concurrency
+
+### Goroutines
+
+- Don't create goroutines in libraries; let the caller control concurrency
+- Always know how a goroutine will exit
+- Use `sync.WaitGroup` or channels to wait for goroutines
+- Avoid goroutine leaks by ensuring cleanup
+
+### Channels
+
+- Use channels to communicate between goroutines
+- Don't communicate by sharing memory; share memory by communicating
+- Close channels from the sender side, not the receiver
+- Use buffered channels when you know the capacity
+- Use `select` for non-blocking operations
+
+### Synchronization
+
+- Use `sync.Mutex` for protecting shared state
+- Keep critical sections small
+- Use `sync.RWMutex` when you have many readers
+- Prefer channels over mutexes when possible
+- Use `sync.Once` for one-time initialization
+
+## Error Handling Patterns
+
+### Creating Errors
+
+- Use `errors.New` for simple static errors
+- Use `fmt.Errorf` for dynamic errors
+- Create custom error types for domain-specific errors
+- Export error variables for sentinel errors
+- Use `errors.Is` and `errors.As` for error checking
+
+### Error Propagation
+
+- Add context when propagating errors up the stack
+- Don't log and return errors (choose one)
+- Handle errors at the appropriate level
+- Consider using structured errors for better debugging
+
+## API Design
+
+### HTTP Handlers
+
+- Use `http.HandlerFunc` for simple handlers
+- Implement `http.Handler` for handlers that need state
+- Use middleware for cross-cutting concerns
+- Set appropriate status codes and headers
+- Handle errors gracefully and return appropriate error responses
+
+### JSON APIs
+
+- Use struct tags to control JSON marshaling
+- Validate input data
+- Use pointers for optional fields
+- Consider using `json.RawMessage` for delayed parsing
+- Handle JSON errors appropriately
+
+## Performance Optimization
+
+### Memory Management
+
+- Minimize allocations in hot paths
+- Reuse objects when possible (consider `sync.Pool`)
+- Use value receivers for small structs
+- Preallocate slices when size is known
+- Avoid unnecessary string conversions
+
+### Profiling
+
+- Use built-in profiling tools (`pprof`)
+- Benchmark critical code paths
+- Profile before optimizing
+- Focus on algorithmic improvements first
+- Consider using `testing.B` for benchmarks
+
+## Testing
+
+### Test Organization
+
+- Keep tests in the same package (white-box testing)
+- Use `_test` package suffix for black-box testing
+- Name test files with `_test.go` suffix
+- Place test files next to the code they test
+
+### Writing Tests
+
+- Use table-driven tests for multiple test cases
+- Name tests descriptively using `Test_functionName_scenario`
+- Use subtests with `t.Run` for better organization
+- Test both success and error cases
+- Use `testify` or similar libraries sparingly
+
+### Test Helpers
+
+- Mark helper functions with `t.Helper()`
+- Create test fixtures for complex setup
+- Use `testing.TB` interface for functions used in tests and benchmarks
+- Clean up resources using `t.Cleanup()`
+
+## Security Best Practices
+
+### Input Validation
+
+- Validate all external input
+- Use strong typing to prevent invalid states
+- Sanitize data before using in SQL queries
+- Be careful with file paths from user input
+- Validate and escape data for different contexts (HTML, SQL, shell)
+
+### Cryptography
+
+- Use standard library crypto packages
+- Don't implement your own cryptography
+- Use crypto/rand for random number generation
+- Store passwords using bcrypt or similar
+- Use TLS for network communication
+
+## Documentation
+
+### Code Documentation
+
+- Document all exported symbols
+- Start documentation with the symbol name
+- Use examples in documentation when helpful
+- Keep documentation close to code
+- Update documentation when code changes
+
+### README and Documentation Files
+
+- Include clear setup instructions
+- Document dependencies and requirements
+- Provide usage examples
+- Document configuration options
+- Include troubleshooting section
+
+## Tools and Development Workflow
+
+### Essential Tools
+
+- `go fmt`: Format code
+- `go vet`: Find suspicious constructs
+- `golint` or `golangci-lint`: Additional linting
+- `go test`: Run tests
+- `go mod`: Manage dependencies
+- `go generate`: Code generation
+
+### Development Practices
+
+- Run tests before committing
+- Use pre-commit hooks for formatting and linting
+- Keep commits focused and atomic
+- Write meaningful commit messages
+- Review diffs before committing
+
+## Common Pitfalls to Avoid
+
+- Not checking errors
+- Ignoring race conditions
+- Creating goroutine leaks
+- Not using defer for cleanup
+- Modifying maps concurrently
+- Not understanding nil interfaces vs nil pointers
+- Forgetting to close resources (files, connections)
+- Using global variables unnecessarily
+- Over-using empty interfaces (`interface{}`)
+- Not considering the zero value of types