refactor: Default examples and codegen to a test-local registry

README.md

@@ -110,7 +110,7 @@ go install github.com/mhiro2/seedling/cmd/seedling-gen@latest
    seedling-gen sql --explain schema.sql
    ```
 
-   This generates struct types, `RegisterBlueprints()`, deterministic `Defaults` for common scalar fields, relations, and Insert stubs. Fill in the `// TODO` callbacks with your DB logic:
+   This generates struct types, `NewRegistry()`, `RegisterBlueprints(reg)`, deterministic `Defaults` for common scalar fields, relations, and Insert stubs. Fill in the `// TODO` callbacks with your DB logic:
 
    ```go
    Insert: func(ctx context.Context, db seedling.DBTX, v Company) (Company, error) {
@@ -127,10 +127,9 @@ go install github.com/mhiro2/seedling/cmd/seedling-gen@latest
 
    ```go
    func TestUser(t *testing.T) {
-       seedling.ResetRegistry()
-       testutil.RegisterBlueprints()
+       reg := testutil.NewRegistry()
 
-       result := seedling.InsertOne[testutil.User](t, db)
+       result := seedling.NewSession[testutil.User](reg).InsertOne(t, db)
        user := result.Root()
 
        if user.ID == 0 {
@@ -146,12 +145,11 @@ go install github.com/mhiro2/seedling/cmd/seedling-gen@latest
 
    ```go
    func TestNamedUser(t *testing.T) {
-       seedling.ResetRegistry()
-       testutil.RegisterBlueprints()
+       reg := testutil.NewRegistry()
 
-       company := seedling.InsertOne[testutil.Company](t, db).Root()
+       company := seedling.NewSession[testutil.Company](reg).InsertOne(t, db).Root()
 
-       result := seedling.InsertOne[testutil.User](t, db,
+       result := seedling.NewSession[testutil.User](reg).InsertOne(t, db,
            seedling.Set("Name", "alice"),
            seedling.Use("company", company),
        )
@@ -161,12 +159,11 @@ go install github.com/mhiro2/seedling/cmd/seedling-gen@latest
    }
 
    func TestTaskProject(t *testing.T) {
-       seedling.ResetRegistry()
-       testutil.RegisterBlueprints()
+       reg := testutil.NewRegistry()
 
        // Only("project") inserts task + project subtree only,
        // skipping the assignee relation entirely.
-       result := seedling.InsertOne[testutil.Task](t, db,
+       result := seedling.NewSession[testutil.Task](reg).InsertOne(t, db,
            seedling.Only("project"),
        )
        _ = result
@@ -191,7 +188,7 @@ go install github.com/mhiro2/seedling/cmd/seedling-gen@latest
 ## 📂 Examples
 
 - [basic](./examples/basic): register blueprints and insert rows with automatic parent creation
-- [quickstart](./examples/quickstart): generated-style `RegisterBlueprints()` flow that matches the README Quick Start
+- [quickstart](./examples/quickstart): generated-style `NewRegistry()` / `RegisterBlueprints(reg)` flow that matches the README Quick Start
 - [custom-defaults](./examples/custom-defaults): customize values with `Set`, `With`, and `Generate`
 - [reuse-parent](./examples/reuse-parent): reuse existing rows with `Use`
 - [batch-insert](./examples/batch-insert): batch inserts with shared `Ref` dependencies and per-row `SeqRef` overrides

cmd/seedling-gen/main_test.go

@@ -235,6 +235,9 @@ func TestGenerate_OutputIncludesExpectedSections(t *testing.T) {
 		{name: "context import", substr: `"context"`, message: "output should import context"},
 		{name: "time import", substr: `"time"`, message: "output should import time"},
 		{name: "seedling import", substr: `"github.com/mhiro2/seedling"`, message: "output should import seedling"},
+		{name: "new registry helper", substr: "func NewRegistry() *seedling.Registry", message: "output should contain local registry helper"},
+		{name: "registry argument", substr: "func RegisterBlueprints(reg *seedling.Registry)", message: "output should accept a registry argument"},
+		{name: "register to registry", substr: "seedling.MustRegisterTo(reg", message: "output should register into the provided registry"},
 		{name: "company struct", substr: "type Company struct", message: "output should contain Company struct"},
 		{name: "user struct", substr: "type User struct", message: "output should contain User struct"},
 		{name: "company blueprint", substr: `Name:    "company"`, message: "output should register company blueprint"},
@@ -315,7 +318,10 @@ func TestGenerate_EmptyInput(t *testing.T) {
 	if !strings.Contains(output, "package empty") {
 		t.Fatalf("expected package declaration, got:\n%s", output)
 	}
-	if !strings.Contains(output, "func RegisterBlueprints()") {
+	if !strings.Contains(output, "func NewRegistry() *seedling.Registry") {
+		t.Fatalf("expected NewRegistry function, got:\n%s", output)
+	}
+	if !strings.Contains(output, "func RegisterBlueprints(reg *seedling.Registry)") {
 		t.Fatalf("expected RegisterBlueprints function, got:\n%s", output)
 	}
 }

cmd/seedling-gen/normalized_ir.go

@@ -53,11 +53,17 @@ type {{.StructName}} struct {
 `
 
 const normalizedBlueprintTemplate = `
-func RegisterBlueprints() {
+func NewRegistry() *seedling.Registry {
+	reg := seedling.NewRegistry()
+	RegisterBlueprints(reg)
+	return reg
+}
+
+func RegisterBlueprints(reg *seedling.Registry) {
 {{- range $i, $model := .}}
 {{- if $i}}
 {{ end }}
-	seedling.MustRegister(seedling.Blueprint[{{$model.TypeExpr}}]{
+	seedling.MustRegisterTo(reg, seedling.Blueprint[{{$model.TypeExpr}}]{
 		Name:  "{{$model.BlueprintID}}",
 		Table: "{{$model.TableName}}",
 {{- if isCompositePK $model}}

doc.go

@@ -52,40 +52,45 @@
 //
 // Register a [Blueprint] for each model that seedling should create:
 //
-//	seedling.MustRegister(seedling.Blueprint[Company]{
-//	    Name:    "company",
-//	    Table:   "companies",
-//	    PKField: "ID",
-//	    Defaults: func() Company {
-//	        return Company{Name: "test-company"}
-//	    },
-//	    Insert: func(ctx context.Context, db seedling.DBTX, v Company) (Company, error) {
-//	        return insertCompany(ctx, db, v)
-//	    },
-//	})
-//
-//	seedling.MustRegister(seedling.Blueprint[User]{
-//	    Name:    "user",
-//	    Table:   "users",
-//	    PKField: "ID",
-//	    Defaults: func() User {
-//	        return User{Name: "test-user"}
-//	    },
-//	    Relations: []seedling.Relation{
-//	        {Name: "company", Kind: seedling.BelongsTo, LocalField: "CompanyID", RefBlueprint: "company"},
-//	    },
-//	    Insert: func(ctx context.Context, db seedling.DBTX, v User) (User, error) {
-//	        return insertUser(ctx, db, v)
-//	    },
-//	})
+//	func registerBlueprints(reg *seedling.Registry) {
+//	    seedling.MustRegisterTo(reg, seedling.Blueprint[Company]{
+//	        Name:    "company",
+//	        Table:   "companies",
+//	        PKField: "ID",
+//	        Defaults: func() Company {
+//	            return Company{Name: "test-company"}
+//	        },
+//	        Insert: func(ctx context.Context, db seedling.DBTX, v Company) (Company, error) {
+//	            return insertCompany(ctx, db, v)
+//	        },
+//	    })
+//
+//	    seedling.MustRegisterTo(reg, seedling.Blueprint[User]{
+//	        Name:    "user",
+//	        Table:   "users",
+//	        PKField: "ID",
+//	        Defaults: func() User {
+//	            return User{Name: "test-user"}
+//	        },
+//	        Relations: []seedling.Relation{
+//	            {Name: "company", Kind: seedling.BelongsTo, LocalField: "CompanyID", RefBlueprint: "company"},
+//	        },
+//	        Insert: func(ctx context.Context, db seedling.DBTX, v User) (User, error) {
+//	            return insertUser(ctx, db, v)
+//	        },
+//	    })
+//	}
 //
 // DBTX is intentionally opaque. Your insert callback and your call sites must
 // agree on the concrete handle type passed as db.
 //
 // Then create rows directly in your tests:
 //
 //	func TestUser(t *testing.T) {
-//	    result := seedling.InsertOne[User](t, db)
+//	    reg := seedling.NewRegistry()
+//	    registerBlueprints(reg)
+//
+//	    result := seedling.NewSession[User](reg).InsertOne(t, db)
 //	    user := result.Root()
 //	    // user.ID and user.CompanyID are populated.
 //	}

docs/guide.md

@@ -258,7 +258,7 @@ Supported locales: `en` (default), `ja`, `zh`, `ko`, `de`, `fr`.
 ## Examples
 
 - [basic](../examples/basic) -- register blueprints and insert rows with automatic parent creation
-- [quickstart](../examples/quickstart) -- generated-style `RegisterBlueprints()` flow that matches the README Quick Start
+- [quickstart](../examples/quickstart) -- generated-style `NewRegistry()` / `RegisterBlueprints(reg)` flow that matches the README Quick Start
 - [custom-defaults](../examples/custom-defaults) -- customize values with `Set`, `With`, and `Generate`
 - [reuse-parent](../examples/reuse-parent) -- reuse existing rows with `Use`
 - [batch-insert](../examples/batch-insert) -- batch inserts with shared `Ref` dependencies and per-row `SeqRef` overrides

examples/basic/basic_test.go

@@ -7,16 +7,17 @@ import (
 	"github.com/mhiro2/seedling/examples/basic"
 )
 
-func setup(t *testing.T) {
+func setup(t *testing.T) *seedling.Registry {
 	t.Helper()
-	seedling.ResetRegistry()
-	basic.RegisterBlueprints()
+	reg := seedling.NewRegistry()
+	basic.RegisterBlueprints(reg)
+	return reg
 }
 
 func TestInsertOne_Company(t *testing.T) {
-	setup(t)
+	reg := setup(t)
 
-	company := seedling.InsertOne[basic.Company](t, nil)
+	company := seedling.NewSession[basic.Company](reg).InsertOne(t, nil)
 
 	if company.Root().ID == 0 {
 		t.Fatal("expected company ID to be set")
@@ -27,10 +28,10 @@ func TestInsertOne_Company(t *testing.T) {
 }
 
 func TestInsertOne_User(t *testing.T) {
-	setup(t)
+	reg := setup(t)
 
 	// InsertOne[User] automatically creates a parent Company.
-	user := seedling.InsertOne[basic.User](t, nil)
+	user := seedling.NewSession[basic.User](reg).InsertOne(t, nil)
 
 	if user.Root().ID == 0 {
 		t.Fatal("expected user ID to be set")
@@ -44,9 +45,9 @@ func TestInsertOne_User(t *testing.T) {
 }
 
 func TestInsertOne_UserWithSet(t *testing.T) {
-	setup(t)
+	reg := setup(t)
 
-	user := seedling.InsertOne[basic.User](t, nil,
+	user := seedling.NewSession[basic.User](reg).InsertOne(t, nil,
 		seedling.Set("Name", "alice"),
 		seedling.Set("Email", "alice@example.com"),
 	)

examples/basic/blueprints.go

@@ -13,10 +13,9 @@ func nextID() int {
 	return int(idSeq.Add(1))
 }
 
-// RegisterBlueprints registers the Company and User blueprints.
-// Call seedling.ResetRegistry() before this in tests to start fresh.
-func RegisterBlueprints() {
-	seedling.MustRegister(seedling.Blueprint[Company]{
+// RegisterBlueprints registers the Company and User blueprints in reg.
+func RegisterBlueprints(reg *seedling.Registry) {
+	seedling.MustRegisterTo(reg, seedling.Blueprint[Company]{
 		Name:    "company",
 		Table:   "companies",
 		PKField: "ID",
@@ -29,7 +28,7 @@ func RegisterBlueprints() {
 		},
 	})
 
-	seedling.MustRegister(seedling.Blueprint[User]{
+	seedling.MustRegisterTo(reg, seedling.Blueprint[User]{
 		Name:    "user",
 		Table:   "users",
 		PKField: "ID",

examples/batch-insert/batch_insert_test.go

@@ -9,19 +9,20 @@ import (
 	batchinsert "github.com/mhiro2/seedling/examples/batch-insert"
 )
 
-func setup(t *testing.T) {
+func setup(t *testing.T) *seedling.Registry {
 	t.Helper()
-	seedling.ResetRegistry()
 	batchinsert.ResetIDs()
-	batchinsert.RegisterBlueprints()
+	reg := seedling.NewRegistry()
+	batchinsert.RegisterBlueprints(reg)
+	return reg
 }
 
 func TestInsertManyE_SharedProject(t *testing.T) {
 	// Arrange
-	setup(t)
+	reg := setup(t)
 
 	// Act
-	result, err := seedling.InsertManyE[batchinsert.Task](context.Background(), nil, 2,
+	result, err := seedling.NewSession[batchinsert.Task](reg).InsertManyE(context.Background(), nil, 2,
 		seedling.Ref("project", seedling.Set("Name", "shared-project")),
 	)
 	if err != nil {
@@ -60,10 +61,10 @@ func TestInsertManyE_SharedProject(t *testing.T) {
 
 func TestInsertManyE_SeqRefCreatesDistinctProjects(t *testing.T) {
 	// Arrange
-	setup(t)
+	reg := setup(t)
 
 	// Act
-	result, err := seedling.InsertManyE[batchinsert.Task](context.Background(), nil, 2,
+	result, err := seedling.NewSession[batchinsert.Task](reg).InsertManyE(context.Background(), nil, 2,
 		seedling.SeqRef("project", func(i int) []seedling.Option {
 			return []seedling.Option{seedling.Set("Name", fmt.Sprintf("project-%d", i))}
 		}),

examples/batch-insert/blueprints.go

@@ -13,9 +13,9 @@ func nextID() int {
 	return int(idSeq.Add(1))
 }
 
-// RegisterBlueprints registers Company, Project, and Task blueprints.
-func RegisterBlueprints() {
-	seedling.MustRegister(seedling.Blueprint[Company]{
+// RegisterBlueprints registers Company, Project, and Task blueprints in reg.
+func RegisterBlueprints(reg *seedling.Registry) {
+	seedling.MustRegisterTo(reg, seedling.Blueprint[Company]{
 		Name:    "company",
 		Table:   "companies",
 		PKField: "ID",
@@ -28,7 +28,7 @@ func RegisterBlueprints() {
 		},
 	})
 
-	seedling.MustRegister(seedling.Blueprint[Project]{
+	seedling.MustRegisterTo(reg, seedling.Blueprint[Project]{
 		Name:    "project",
 		Table:   "projects",
 		PKField: "ID",
@@ -44,7 +44,7 @@ func RegisterBlueprints() {
 		},
 	})
 
-	seedling.MustRegister(seedling.Blueprint[Task]{
+	seedling.MustRegisterTo(reg, seedling.Blueprint[Task]{
 		Name:    "task",
 		Table:   "tasks",
 		PKField: "ID",

examples/custom-defaults/blueprints.go

@@ -13,9 +13,9 @@ func nextID() int {
 	return int(idSeq.Add(1))
 }
 
-// RegisterBlueprints registers the User blueprint with sensible defaults.
-func RegisterBlueprints() {
-	seedling.MustRegister(seedling.Blueprint[User]{
+// RegisterBlueprints registers the User blueprint with sensible defaults in reg.
+func RegisterBlueprints(reg *seedling.Registry) {
+	seedling.MustRegisterTo(reg, seedling.Blueprint[User]{
 		Name:    "user",
 		Table:   "users",
 		PKField: "ID",