hexago add domain¶

Add domain entities or value objects to an existing project.

Synopsis¶

hexago add domain entity <name> [flags]
hexago add domain valueobject <name> [flags]

Operates on the project root — use --working-directory (-w) to target a project without changing directories.

Subcommands¶

entity¶

Add a domain entity — a mutable business object with identity.

hexago add domain entity <name> [--fields "field:type,field:type"]

Flags:

Flag	Short	Type	Default	Description
`--fields`	`-f`	string	`""`	Comma-separated `field:type` pairs

Field Types:

Any valid Go type: string, int, int64, float64, bool, time.Time, etc.

Reserved keyword handling:

Field names that lower-case to a Go reserved keyword (type, map, range, func, chan, etc.) are automatically renamed in the generated constructor by appending Val. The struct field itself is unaffected.

# "type" is a reserved keyword — hexago handles it automatically
hexago add domain entity Movement \
  --fields "productEan13:string,type:string,quantity:float64"

// struct field stays "Type"; constructor parameter becomes "typeVal"
func NewMovement(productEan13 string, typeVal string, quantity float64) (*Movement, error) {
    return &Movement{
        ProductEan13: productEan13,
        Type:         typeVal,
        Quantity:     quantity,
    }, nil
}

Examples:

hexago add domain entity User --fields "id:string,name:string,email:string"
hexago add domain entity Order --fields "id:string,total:float64,createdAt:time.Time"
hexago add domain entity Product --fields "id:string,name:string,price:float64,stock:int"

valueobject¶

Add a value object — an immutable domain concept defined by its attributes, not identity.

hexago add domain valueobject <name> [--fields "field:type"] [--entity <entity>]

Flags:

Flag	Short	Type	Default	Description
`--fields`	`-f`	string	`""`	Comma-separated `field:type` pairs
`--entity`	`-e`	string	`""`	Entity name to co-locate with (entity-bound); omit for standalone sub-package

Examples:

hexago add domain valueobject Email
hexago add domain valueobject Money --fields "amount:float64,currency:string"
hexago add domain valueobject Address --fields "street:string,city:string,country:string"
hexago add domain valueobject StockLevel --fields "value:float64" --entity Product

Generated Files¶

For hexago add domain entity User --fields "id:string,name:string,email:string":

internal/core/domain/users/
├── users.go          # Entity definition
├── port.go           # Repository port interface
└── users_test.go     # Test file

Value objects are generated either as a standalone sub-package or co-located with an entity:

# Standalone — own sub-package
hexago add domain valueobject Email
# → internal/core/domain/email/email.go

# Entity-bound — co-located with entity
hexago add domain valueobject StockLevel --entity Product
# → internal/core/domain/products/stock_level.go

Generated Code Structure¶

Entity (in internal/core/domain/users/users.go):

package users

// User represents the User entity
type User struct {
    ID    string
    Name  string
    Email string
}

// NewUser creates a new User entity
func NewUser(id string, name string, email string) *User {
    return &User{
        ID:    id,
        Name:  name,
        Email: email,
    }
}

Value Object (standalone, in internal/core/domain/email/email.go):

package email

// Email represents the Email value object
type Email struct {
    // TODO: Add fields
}

// NewEmail creates a new Email value object
func NewEmail() (*Email, error) {
    // TODO: Add validation
    return &Email{}, nil
}

Architecture Notes¶

Domain objects belong to the core layer and must:

✅ Contain pure business logic and validation
✅ Be self-contained with zero external dependencies
❌ Never import adapter packages
❌ Never import infrastructure packages
❌ Never import external libraries (no database drivers, HTTP clients, etc.)