golang-development

name	golang-development
description	Develop Go backend features in DBO Studio following layered architecture, apperror/response patterns, and database driver conventions. Use when writing, reviewing, or refactoring Go code in backend/, adding API endpoints, database drivers, or Go tests.

DBO Go Development

Quick Start

1. Read AGENTS.md and backend/AGENTS.md
2. Find a similar feature in the same layer; mirror its patterns
3. Implement bottom-up: DTO → repo → service → handler → route
4. Run go fmt ./..., golangci-lint run, go test ./...

Architecture

handler (Fiber) → service → repository (app SQLite)
                         ↘ database.NewDatabaseRepository() (user DB)

New API Endpoint Workflow

- [ ] DTO in internal/app/dto/ with Validate()
- [ ] Repo method in internal/repository/ (if app DB)
- [ ] Service interface + impl + mapper in internal/service/<domain>/
- [ ] Handler in internal/app/handler/
- [ ] Route in internal/app/server/route.go
- [ ] Wire in cmd/cmd.go if new handler/service
- [ ] go fmt && golangci-lint run && go test ./...

Key Patterns

Package naming

Directory saved_query/ → package serviceSavedQuery with alias import.

Error handling

// Service
return nil, apperror.NotFound(apperror.ErrSavedQueryNotFound)

// Handler
return response.ErrorBuilder().FromError(err).Send(c)

Interface + impl

type ISavedQueryService interface { ... }
var _ ISavedQueryService = (*ISavedQueryServiceImpl)(nil)
func NewSavedQueryService(repo repository.ISavedQueryRepo) ISavedQueryService

Database driver feature

1. Add to internal/database/contract/contract.go
2. Implement in internal/database/<driver>/
3. Assert in contracts_assertions.go
4. Table-driven test for SQL generation

Do NOT

• Put business logic in handlers
• Return raw HTTP status from services
• Use panic in service/library code
• Create util/common packages
• Import upward (database → service)

Reference Files

• Handler example: backend/internal/app/handler/saved_query.go
• Service example: backend/internal/service/saved_query/saved_query_service.go
• Errors: backend/pkg/apperror/errors.go
• DB factory: backend/internal/database/repository.go
• Contract: backend/internal/database/contract/contract.go

Cursor Rules

Auto-applied when editing backend/**/*.go:

• go-core.mdc — idiomatic Go
• go-dbo-architecture.mdc — layer patterns
• go-concurrency.mdc — context/goroutines
• go-testing.mdc — test conventions
• go-tooling.mdc — lint/format