add seeding demo

cmd/seed.go

@@ -0,0 +1,52 @@
+/*
+Copyright © 2023 NAME HERE <EMAIL ADDRESS>
+*/
+package cmd
+
+import (
+	_ "atom/database/seeders"
+	_ "atom/providers"
+
+	"atom/container"
+	"atom/contracts"
+	"log"
+
+	"github.com/spf13/cobra"
+	"go.uber.org/dig"
+	"gorm.io/gorm"
+)
+
+// seedCmd represents the seed command
+var seedCmd = &cobra.Command{
+	Use:   "seed",
+	Short: "seed databases",
+	Long:  `seed your database with data using seeders.`,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		return container.Container.Invoke(func(seedersContainer SeedersContainer) error {
+			if len(seedersContainer.Seeders) == 0 {
+				log.Print("no seeder exists")
+				return nil
+			}
+
+			for _, seeder := range seedersContainer.Seeders {
+				log.Printf("seed table (%s) for %d times", seeder.Table(), seeder.Times())
+				seeder.Run(seedersContainer.DB)
+			}
+			return nil
+		})
+	},
+	PostRun: func(cmd *cobra.Command, args []string) {
+		log.Println("BINGO! seeding done")
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(seedCmd)
+}
+
+type SeedersContainer struct {
+	dig.In
+
+	DB      *gorm.DB
+	Seeders []contracts.Seeder `group:"seeders"`
+}

contracts/seeder.go

@@ -0,0 +1,10 @@
+package contracts
+
+import "gorm.io/gorm"
+
+// Migration route interface
+type Seeder interface {
+	Times() uint
+	Table() string
+	Run(*gorm.DB)
+}

database/seeders/user.go

@@ -0,0 +1,59 @@
+package seeders
+
+import (
+	"atom/container"
+	"atom/contracts"
+	"fmt"
+	"log"
+	"time"
+
+	"go.uber.org/dig"
+	"gorm.io/gorm"
+)
+
+func init() {
+	if err := container.Container.Provide(NewUserSeeder, dig.Group("seeders")); err != nil {
+		log.Fatal(err)
+	}
+}
+
+type UserSeeder struct {
+}
+
+func NewUserSeeder() contracts.Seeder {
+	return &UserSeeder{}
+}
+
+type User struct {
+	gorm.Model
+
+	Username string
+	Password string
+	Birthday time.Time
+	Status   bool
+}
+
+func (s *UserSeeder) Times() uint {
+	return 10
+}
+
+func (s *UserSeeder) Run(db *gorm.DB) {
+	var i uint
+	for i = 0; i < s.Times(); i++ {
+		data := s.Generate(i)
+		db.Table(s.Table()).Create(&data)
+	}
+}
+
+func (s *UserSeeder) Table() string {
+	return "users"
+}
+
+func (s *UserSeeder) Generate(idx uint) User {
+	return User{
+		Username: fmt.Sprintf("username: %d", idx),
+		Password: fmt.Sprintf("password: %d", idx),
+		Birthday: time.Now().Add(time.Hour * 24 * time.Duration(idx)),
+		Status:   idx%2 == 0,
+	}
+}