refactor: expose different commands from standalone / embeded CLI

The bootstrapped CLI which will be compiled along with the rest
of the user migration files does not need the Init command.

On the other hand, the standalone bundb command will provide that
and exclude all other commands to avoid confusion between them.

cmd/bundb/main.go

@@ -33,8 +33,7 @@ import (
 
 func main() {
 	log.SetPrefix("bundb: ")
-	// TODO: use buncli.New(buncli.FromPlugin()) to read config from plugin
-	if err := buncli.Run(os.Args, nil); err != nil {
+	if err := buncli.NewStandalone("bundb").Run(os.Args); err != nil {
 		log.Fatal(err)
 	}
 }

extra/buncli/buncli.go

@@ -24,8 +24,10 @@ var bunApp = &cli.App{
 
 // New creates a new CLI application for managing bun migrations.
 func New(c *Config) *App {
+	if c.RootName != "" {
+		bunApp.Name = c.RootName
+	}
 	bunApp.Commands = cli.Commands{
-		CmdInit(),
 		CmdMigrate(c),
 		CmdRollback(c),
 		CmdCreate(c),
@@ -37,7 +39,23 @@ func New(c *Config) *App {
 	}
 }
 
+// NewStandalone create a new CLI application to be distributed as a standalone binary.
+// It's intended to be used in the cmb/bund and does not require any prior setup from the user:
+// the app only includes the Init command and reads all its configuration from command line.
+//
+// Prefer using New(*Config) in your custom entrypoint.
+func NewStandalone(name string) *App {
+	bunApp.Name = name
+	bunApp.Commands = cli.Commands{
+		CmdInit(),
+	}
+	return &App{
+		App: bunApp,
+	}
+}
+
 type Config struct {
+	RootName           string
 	DB                 *bun.DB
 	AutoMigrator       *migrate.AutoMigrator
 	Migrations         *migrate.Migrations

extra/buncli/go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/uptrace/bun/driver/pgdriver v1.2.7-0.20241126124946-928d0779110e
 	github.com/uptrace/bun/driver/sqliteshim v1.2.7-0.20241126124946-928d0779110e
 	github.com/urfave/cli/v2 v2.27.5
+	golang.org/x/mod v0.22.0
 )
 
 require (
@@ -32,7 +33,6 @@ require (
 	github.com/xrash/smetrics v0.0.0-20240521201337-686a1a2994c1 // indirect
 	golang.org/x/crypto v0.29.0 // indirect
 	golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f // indirect
-	golang.org/x/mod v0.22.0 // indirect
 	golang.org/x/sys v0.27.0 // indirect
 	mellium.im/sasl v0.3.2 // indirect
 	modernc.org/gc/v3 v3.0.0-20241004144649-1aea3fae8852 // indirect

extra/buncli/init.go

@@ -127,6 +127,7 @@ func main() {
 	var _ /* auto */ migrate.AutoMigrator
 
 	if err := buncli.Run(os.Args, &buncli.Config{
+		RootName: %q,
 		// DB: db,
 		// AutoMigrator: auto,
 		Migrations: migrations.Migrations,
@@ -160,7 +161,7 @@ func initCmd(binDir string, migrationsDir string) error {
 
 	pkgMigrations := path.Join(modPath, strings.TrimLeft(migrationsDir, "."))
 	log.Print("pkgMigrations: ", pkgMigrations)
-	if _, err := fmt.Fprintf(f, entrypointTemplate, pkgMigrations); err != nil {
+	if _, err := fmt.Fprintf(f, entrypointTemplate, pkgMigrations, defaultBin); err != nil {
 		log.Print("here!")
 		return err
 	}
@@ -259,6 +260,7 @@ func newDB(ctx *cli.Context) (*bun.DB, error) {
 	return bun.NewDB(sqlDB, dialect), nil
 }
 
+// getModPath parses the ./go.mod file in the current directory and returns the declared module path.
 func getModPath() (string, error) {
 	f, err := os.ReadFile("go.mod")
 	if err != nil {