Common Errors

DI Resolution Errors

❌ Cannot resolve type for constructor

❌ DI Error: Cannot resolve '*UserService' for constructor

Cause: The required dependency is not registered in the DI container.

Solution: Make sure the dependency is registered as a provider in some module:

// Check that the dependency is in a module's Providers()
func (m *UsersModule) Providers() []interface{} {
    return []interface{}{
        NewUserService,     // ← Must be registered
        NewUserRepository,  // ← Must be registered
    }
}

❌ Module import order issue

Cause: Provider A depends on Provider B, but B's module is imported after A's module.

Solution: Import the module containing Provider B first:

func (m *AppModule) Imports() []nika.Module {
    return []nika.Module{
        NewDatabaseModule(),  // ← Import first (provides Database)
        NewUsersModule(),     // ← UsersModule depends on Database
    }
}

Controller Errors

❌ Controller must be a pointer to a struct

panic: Controller must be a pointer to a struct

Cause: You passed a non-pointer to the controller.

Solution:

// Wrong
func (m *AppModule) Controllers() []interface{} {
    return []interface{}{UserController{}} // ← Not a pointer
}

// Correct
func (m *AppModule) Controllers() []interface{} {
    return []interface{}{NewUserController} // ← Pass constructor
}

❌ Invalid route tag

panic: Invalid route tag in List

Cause: The route tag is malformed.

Solution: Use the correct format METHOD:path:

// Wrong
List func(*gin.Context) `route:"GET/users"`      // Missing colon
List func(*gin.Context) `route:"GET:/users" `    // Extra space

// Correct
List func(*gin.Context) `route:"GET:/users"`

❌ Field must be a function

panic: Field List must be a function

Cause: The tagged field is not a function.

Solution: Ensure the field type is func(*gin.Context).

❌ Route handler field must be exported

panic: Route handler field list must be exported

Cause: The field name starts with a lowercase letter.

Solution: Use uppercase for route handler fields:

// Wrong
list func(*gin.Context) `route:"GET:/users"`   // lowercase

// Correct
List func(*gin.Context) `route:"GET:/users"`    // Uppercase

Unsupported Method

panic: Unsupported method: HEAD

Cause: The HTTP method is not supported.

Supported methods: GET, POST, PUT, PATCH, DELETE, OPTIONS

Validator Errors

❌ validator: not initialized

panic: validator: not initialized — call validator.Setup(app, ...) before use

Cause: validator.Setup() was not called before using validation helpers.

Solution: Call Setup in your main function:

func main() {
    app := nika.NewApp()
    validator.Setup(app) // ← Add this
    app.LoadModule(rootModule)
    app.Listen(":3000")
}

Cache Errors

❌ unknown cache driver

unknown cache driver: postgres

Supported drivers: redis, file

❌ memcached provider not implemented

The memcached driver is not yet implemented. Use redis or file instead.