factory-go is a fixtures replacement inspired by factory_boy and factory_bot.
It can be generated easily complex objects by using this, and maintain easily those objects generaters.
$ go get -u github.com/bluele/factory-go/factory All of the following code on examples.
- Define a simple factory
- Use factory with random yet realistic values
- Define a factory includes sub-factory
- Define a factory includes a slice for sub-factory
- Define a factory includes sub-factory that contains self-reference
- Define a sub-factory refers to parent factory
Declare an factory has a set of simple attribute, and generate a fixture object.
package main import ( "fmt" "github.com/bluele/factory-go/factory" ) type User struct { ID int Name string Location string } // 'Location: "Tokyo"' is default value. var UserFactory = factory.NewFactory( &User{Location: "Tokyo"}, ).SeqInt("ID", func(n int) (interface{}, error) { return n, nil }).Attr("Name", func(args factory.Args) (interface{}, error) { user := args.Instance().(*User) return fmt.Sprintf("user-%d", user.ID), nil }) func main() { for i := 0; i < 3; i++ { user := UserFactory.MustCreate().(*User) fmt.Println("ID:", user.ID, " Name:", user.Name, " Location:", user.Location) } }Output:
ID: 1 Name: user-1 Location: Tokyo ID: 2 Name: user-2 Location: Tokyo ID: 3 Name: user-3 Location: Tokyo Tests look better with random yet realistic values. For example, you can use go-randomdata library to get them:
package main import ( "fmt" "github.com/Pallinder/go-randomdata" "github.com/bluele/factory-go/factory" ) type User struct { ID int Name string Location string } // 'Location: "Tokyo"' is default value. var UserFactory = factory.NewFactory( &User{}, ).SeqInt("ID", func(n int) (interface{}, error) { return n, nil }).Attr("Name", func(args factory.Args) (interface{}, error) { return randomdata.FullName(randomdata.RandomGender), nil }).Attr("Location", func(args factory.Args) (interface{}, error) { return randomdata.City(), nil }) func main() { for i := 0; i < 3; i++ { user := UserFactory.MustCreate().(*User) fmt.Println("ID:", user.ID, " Name:", user.Name, " Location:", user.Location) } }Output:
ID: 1 Name: Benjamin Thomas Location: Burrton ID: 2 Name: Madison Davis Location: Brandwell ID: 3 Name: Aubrey Robinson Location: Campden package main import ( "fmt" "github.com/bluele/factory-go/factory" ) type Group struct { ID int Name string } type User struct { ID int Name string Location string Group *Group } var GroupFactory = factory.NewFactory( &Group{}, ).SeqInt("ID", func(n int) (interface{}, error) { return 2 - n%2, nil }).Attr("Name", func(args factory.Args) (interface{}, error) { group := args.Instance().(*Group) return fmt.Sprintf("group-%d", group.ID), nil }) // 'Location: "Tokyo"' is default value. var UserFactory = factory.NewFactory( &User{Location: "Tokyo"}, ).SeqInt("ID", func(n int) (interface{}, error) { return n, nil }).Attr("Name", func(args factory.Args) (interface{}, error) { user := args.Instance().(*User) return fmt.Sprintf("user-%d", user.ID), nil }).SubFactory("Group", GroupFactory) func main() { for i := 0; i < 3; i++ { user := UserFactory.MustCreate().(*User) fmt.Println( "ID:", user.ID, " Name:", user.Name, " Location:", user.Location, " Group.ID:", user.Group.ID, " Group.Name", user.Group.Name) } }Output:
ID: 1 Name: user-1 Location: Tokyo Group.ID: 1 Group.Name group-1 ID: 2 Name: user-2 Location: Tokyo Group.ID: 2 Group.Name group-2 ID: 3 Name: user-3 Location: Tokyo Group.ID: 1 Group.Name group-1 package main import ( "fmt" "github.com/bluele/factory-go/factory" ) type Post struct { ID int Content string } type User struct { ID int Name string Posts []*Post } var PostFactory = factory.NewFactory( &Post{}, ).SeqInt("ID", func(n int) (interface{}, error) { return n, nil }).Attr("Content", func(args factory.Args) (interface{}, error) { post := args.Instance().(*Post) return fmt.Sprintf("post-%d", post.ID), nil }) var UserFactory = factory.NewFactory( &User{}, ).SeqInt("ID", func(n int) (interface{}, error) { return n, nil }).Attr("Name", func(args factory.Args) (interface{}, error) { user := args.Instance().(*User) return fmt.Sprintf("user-%d", user.ID), nil }).SubSliceFactory("Posts", PostFactory, func() int { return 3 }) func main() { for i := 0; i < 3; i++ { user := UserFactory.MustCreate().(*User) fmt.Println("ID:", user.ID, " Name:", user.Name) for _, post := range user.Posts { fmt.Printf("\tPost.ID: %v Post.Content: %v\n", post.ID, post.Content) } } }Output:
ID: 1 Name: user-1 Post.ID: 1 Post.Content: post-1 Post.ID: 2 Post.Content: post-2 Post.ID: 3 Post.Content: post-3 ID: 2 Name: user-2 Post.ID: 4 Post.Content: post-4 Post.ID: 5 Post.Content: post-5 Post.ID: 6 Post.Content: post-6 ID: 3 Name: user-3 Post.ID: 7 Post.Content: post-7 Post.ID: 8 Post.Content: post-8 Post.ID: 9 Post.Content: post-9 package main import ( "fmt" "github.com/Pallinder/go-randomdata" "github.com/bluele/factory-go/factory" ) type User struct { ID int Name string CloseFriend *User } var UserFactory = factory.NewFactory( &User{}, ) func init() { UserFactory.SeqInt("ID", func(n int) (interface{}, error) { return n, nil }).Attr("Name", func(args factory.Args) (interface{}, error) { return randomdata.FullName(randomdata.RandomGender), nil }).SubRecursiveFactory("CloseFriend", UserFactory, func() int { return 2 }) // recursive depth is always 2 } func main() { user := UserFactory.MustCreate().(*User) fmt.Println("ID:", user.ID, " Name:", user.Name, " CloseFriend.ID:", user.CloseFriend.ID, " CloseFriend.Name:", user.CloseFriend.Name) // `user.CloseFriend.CloseFriend.CloseFriend ` depth is 3, so this value is always nil. fmt.Printf("%v %v\n", user.CloseFriend.CloseFriend, user.CloseFriend.CloseFriend.CloseFriend) }Output:
ID: 1 Name: Mia Williams CloseFriend.ID: 2 CloseFriend.Name: Joseph Wilson &{3 Liam Wilson <nil>} <nil> package main import ( "fmt" "github.com/bluele/factory-go/factory" ) type User struct { ID int Name string Group *Group } type Group struct { ID int Name string Users []*User } var UserFactory = factory.NewFactory( &User{}, ).SeqInt("ID", func(n int) (interface{}, error) { return n, nil }).Attr("Name", func(args factory.Args) (interface{}, error) { user := args.Instance().(*User) return fmt.Sprintf("user-%d", user.ID), nil }).Attr("Group", func(args factory.Args) (interface{}, error) { if parent := args.Parent(); parent != nil { // if args have parent, use it. return parent.Instance(), nil } return nil, nil }) var GroupFactory = factory.NewFactory( &Group{}, ).SeqInt("ID", func(n int) (interface{}, error) { return 2 - n%2, nil }).Attr("Name", func(args factory.Args) (interface{}, error) { group := args.Instance().(*Group) return fmt.Sprintf("group-%d", group.ID), nil }).SubSliceFactory("Users", UserFactory, func() int { return 3 }) func main() { group := GroupFactory.MustCreate().(*Group) fmt.Println("Group.ID:", group.ID) for _, user := range group.Users { fmt.Println("\tUser.ID:", user.ID, " User.Name:", user.Name, " User.Group.ID:", user.Group.ID) } }Output:
Group.ID: 1 User.ID: 1 User.Name: user-1 User.Group.ID: 1 User.ID: 2 User.Name: user-2 User.Group.ID: 1 User.ID: 3 User.Name: user-3 User.Group.ID: 1 Currently this project has no support for directly integration with ORM like gorm, so you need to do manually.
Here is an example: https://github.com/bluele/factory-go/blob/master/examples/gorm_integration.go
Jun Kimura