📜 ResolveSpec 📜

ResolveSpec is a flexible and powerful REST API specification and implementation that provides GraphQL-like capabilities while maintaining REST simplicity. It allows for dynamic data querying, relationship preloading, and complex filtering through a clean, URL-based interface.

🆕 New in v2.0: Database-agnostic architecture with support for GORM, Bun, and other ORMs. Router-flexible design works with Gorilla Mux, Gin, Echo, and more.

Table of Contents

• Features
• Installation
• Quick Start
  • Existing Code (Backward Compatible)
  • New Database-Agnostic API
  • Router Integration
• Migration from v1.x
• Architecture
• API Structure
• Example Usage
• Testing
• What's New in v2.0

Features

• Dynamic Data Querying: Select specific columns and relationships to return
• Relationship Preloading: Load related entities with custom column selection and filters
• Complex Filtering: Apply multiple filters with various operators
• Sorting: Multi-column sort support
• Pagination: Built-in limit and offset support
• Computed Columns: Define virtual columns for complex calculations
• Custom Operators: Add custom SQL conditions when needed
• 🆕 Database Agnostic: Works with GORM, Bun, or any database layer through adapters
• 🆕 Router Flexible: Integrates with Gorilla Mux, Gin, Echo, or custom routers
• 🆕 Backward Compatible: Existing code works without changes
• 🆕 Better Testing: Mockable interfaces for easy unit testing

API Structure

URL Patterns

/[schema]/[table_or_entity]/[id]
/[schema]/[table_or_entity]
/[schema]/[function]
/[schema]/[virtual]

Request Format

{
  "operation": "read|create|update|delete",
  "data": {
    // For create/update operations
  },
  "options": {
    "preload": [...],
    "columns": [...],
    "filters": [...],
    "sort": [...],
    "limit": number,
    "offset": number,
    "customOperators": [...],
    "computedColumns": [...]
  }
}

Example Usage

Reading Data with Related Entities

POST /core/users
{
  "operation": "read",
  "options": {
    "columns": ["id", "name", "email"],
    "preload": [
      {
        "relation": "posts",
        "columns": ["id", "title"],
        "filters": [
          {
            "column": "status",
            "operator": "eq",
            "value": "published"
          }
        ]
      }
    ],
    "filters": [
      {
        "column": "active",
        "operator": "eq",
        "value": true
      }
    ],
    "sort": [
      {
        "column": "created_at",
        "direction": "desc"
      }
    ],
    "limit": 10,
    "offset": 0
  }
}

Installation

go get github.com/Warky-Devs/ResolveSpec

Quick Start

Option 1: Existing Code (Backward Compatible)

Your existing code continues to work without any changes:

import "github.com/Warky-Devs/ResolveSpec/pkg/resolvespec"

// This still works exactly as before
handler := resolvespec.NewAPIHandler(gormDB)
handler.RegisterModel("core", "users", &User{})

Migration from v1.x

ResolveSpec v2.0 introduces a new database and router abstraction layer while maintaining 100% backward compatibility. Your existing code will continue to work without any changes.

Migration Timeline

1. Phase 1: Continue using existing API (no changes needed)
2. Phase 2: Gradually adopt new constructors when convenient
3. Phase 3: Switch to interface-based approach for new features
4. Phase 4: Optionally switch database backends

Detailed Migration Guide

For detailed migration instructions, examples, and best practices, see MIGRATION_GUIDE.md.

Architecture

Database Abstraction Layer

Your Application Code
        ↓
   Handler (Business Logic)  
        ↓
   Database Interface
        ↓
   [GormAdapter] [BunAdapter] [CustomAdapter]
        ↓              ↓           ↓
    [GORM]         [Bun]    [Your ORM]

Supported Database Layers

• GORM (default, fully supported)
• Bun (ready to use, included in dependencies)
• Custom ORMs (implement the Database interface)

Supported Routers

• Gorilla Mux (built-in support with SetupRoutes())
• BunRouter (built-in support with SetupBunRouterWithResolveSpec())
• Gin (manual integration, see examples above)
• Echo (manual integration, see examples above)
• Custom Routers (implement request/response adapters)

Option 2: New Database-Agnostic API

With GORM (Recommended Migration Path)

import "github.com/Warky-Devs/ResolveSpec/pkg/resolvespec"

// Create database adapter
dbAdapter := resolvespec.NewGormAdapter(gormDB)

// Create model registry  
registry := resolvespec.NewModelRegistry()
registry.RegisterModel("core.users", &User{})
registry.RegisterModel("core.posts", &Post{})

// Create handler
handler := resolvespec.NewHandler(dbAdapter, registry)

With Bun ORM

import "github.com/Warky-Devs/ResolveSpec/pkg/resolvespec"
import "github.com/uptrace/bun"

// Create Bun adapter (Bun dependency already included)
dbAdapter := resolvespec.NewBunAdapter(bunDB)

// Rest is identical to GORM
registry := resolvespec.NewModelRegistry()
handler := resolvespec.NewHandler(dbAdapter, registry)

Router Integration

Gorilla Mux (Built-in Support)

import "github.com/gorilla/mux"

// Backward compatible way
router := mux.NewRouter()  
resolvespec.SetupRoutes(router, handler)

// Or manually:
router.HandleFunc("/{schema}/{entity}", func(w http.ResponseWriter, r *http.Request) {
    vars := mux.Vars(r)
    handler.Handle(w, r, vars)
}).Methods("POST")

Gin (Custom Integration)

import "github.com/gin-gonic/gin"

func setupGin(handler *resolvespec.Handler) *gin.Engine {
    r := gin.Default()
    
    r.POST("/:schema/:entity", func(c *gin.Context) {
        params := map[string]string{
            "schema": c.Param("schema"),
            "entity": c.Param("entity"),
        }
        
        // Use new adapter interfaces
        reqAdapter := resolvespec.NewHTTPRequest(c.Request)
        respAdapter := resolvespec.NewHTTPResponseWriter(c.Writer)
        handler.Handle(respAdapter, reqAdapter, params)
    })
    
    return r
}

Echo (Custom Integration)

import "github.com/labstack/echo/v4"

func setupEcho(handler *resolvespec.Handler) *echo.Echo {
    e := echo.New()
    
    e.POST("/:schema/:entity", func(c echo.Context) error {
        params := map[string]string{
            "schema": c.Param("schema"),
            "entity": c.Param("entity"),
        }
        
        reqAdapter := resolvespec.NewHTTPRequest(c.Request())
        respAdapter := resolvespec.NewHTTPResponseWriter(c.Response().Writer)
        handler.Handle(respAdapter, reqAdapter, params)
        return nil
    })
    
    return e
}

BunRouter (Built-in Support)

import "github.com/uptrace/bunrouter"

// Simple setup with built-in function
func setupBunRouter(handler *resolvespec.APIHandlerCompat) *bunrouter.Router {
    router := bunrouter.New()
    resolvespec.SetupBunRouterWithResolveSpec(router, handler)
    return router
}

// Or use the adapter
func setupBunRouterAdapter() *resolvespec.StandardBunRouterAdapter {
    routerAdapter := resolvespec.NewStandardBunRouterAdapter()
    
    // Register routes manually
    routerAdapter.RegisterRouteWithParams("POST", "/:schema/:entity", 
        []string{"schema", "entity"}, 
        func(w http.ResponseWriter, r *http.Request, params map[string]string) {
            // Your handler logic
        })
    
    return routerAdapter
}

// Full uptrace stack (bunrouter + Bun ORM)
func setupFullUptrace(bunDB *bun.DB) *bunrouter.Router {
    // Database adapter
    dbAdapter := resolvespec.NewBunAdapter(bunDB)
    registry := resolvespec.NewModelRegistry()
    handler := resolvespec.NewHandler(dbAdapter, registry)
    
    // Router
    router := resolvespec.NewStandardBunRouterAdapter()
    resolvespec.SetupBunRouterWithResolveSpec(router.GetBunRouter(), 
        &resolvespec.APIHandlerCompat{
            newHandler: handler,
        })
    
    return router.GetBunRouter()
}

Configuration

Model Registration

type User struct {
    ID    uint   `json:"id" gorm:"primaryKey"`
    Name  string `json:"name"`
    Email string `json:"email"`
    Posts []Post `json:"posts,omitempty" gorm:"foreignKey:UserID"`
}

handler.RegisterModel("core", "users", &User{})

Features in Detail

Filtering

Supported operators:

• eq: Equal
• neq: Not Equal
• gt: Greater Than
• gte: Greater Than or Equal
• lt: Less Than
• lte: Less Than or Equal
• like: LIKE pattern matching
• ilike: Case-insensitive LIKE
• in: IN clause

Sorting

Support for multiple sort criteria with direction:

"sort": [
  {
    "column": "created_at",
    "direction": "desc"
  },
  {
    "column": "name",
    "direction": "asc"
  }
]

Computed Columns

Define virtual columns using SQL expressions:

"computedColumns": [
  {
    "name": "full_name",
    "expression": "CONCAT(first_name, ' ', last_name)"
  }
]

Testing

With New Architecture (Mockable)

import "github.com/stretchr/testify/mock"

// Create mock database
type MockDatabase struct {
    mock.Mock
}

func (m *MockDatabase) NewSelect() resolvespec.SelectQuery {
    args := m.Called()
    return args.Get(0).(resolvespec.SelectQuery)
}

// Test your handler with mocks
func TestHandler(t *testing.T) {
    mockDB := &MockDatabase{}
    mockRegistry := resolvespec.NewModelRegistry()
    handler := resolvespec.NewHandler(mockDB, mockRegistry)
    
    // Setup mock expectations
    mockDB.On("NewSelect").Return(&MockSelectQuery{})
    
    // Test your logic
    // ... test code
}

Security Considerations

• Implement proper authentication and authorization
• Validate all input parameters
• Use prepared statements (handled by GORM/Bun/your ORM)
• Implement rate limiting
• Control access at schema/entity level
• New: Database abstraction layer provides additional security through interface boundaries

Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

What's New in v2.0

Breaking Changes

• None! Full backward compatibility maintained

New Features

• Database Abstraction: Support for GORM, Bun, and custom ORMs
• Router Flexibility: Works with any HTTP router through adapters
• BunRouter Integration: Built-in support for uptrace/bunrouter
• Better Architecture: Clean separation of concerns with interfaces
• Enhanced Testing: Mockable interfaces for comprehensive testing
• Migration Guide: Step-by-step migration instructions

Performance Improvements

• More efficient query building through interface design
• Reduced coupling between components
• Better memory management with interface boundaries

Acknowledgments

• Inspired by REST, OData, and GraphQL's flexibility
• Database Support: GORM and Bun
• Router Support: Gorilla Mux (built-in), Gin, Echo, and others through adapters
• Slogan generated using DALL-E
• AI used for documentation checking and correction
• Community feedback and contributions that made v2.0 possible