add profile actors

pkg/profile/id.go

@@ -0,0 +1,70 @@
+package profile
+
+import (
+	"crypto/rand"
+	"fmt"
+)
+
+// ProfileId is a 64-bit profile identifier with a compact base62 string form,
+// the same scheme the cart and order use so ids are consistent across services.
+type ProfileId uint64
+
+const base62Alphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+
+var base62Rev [256]byte
+
+func init() {
+	for i := range base62Rev {
+		base62Rev[i] = 0xFF
+	}
+	for i := 0; i < len(base62Alphabet); i++ {
+		base62Rev[base62Alphabet[i]] = byte(i)
+	}
+}
+
+// String returns the canonical base62 encoding.
+func (id ProfileId) String() string { return encodeBase62(uint64(id)) }
+
+// NewProfileId generates a cryptographically random non-zero id.
+func NewProfileId() (ProfileId, error) {
+	var b [8]byte
+	if _, err := rand.Read(b[:]); err != nil {
+		return 0, fmt.Errorf("NewProfileId: %w", err)
+	}
+	u := uint64(b[0])<<56 | uint64(b[1])<<48 | uint64(b[2])<<40 | uint64(b[3])<<32 |
+		uint64(b[4])<<24 | uint64(b[5])<<16 | uint64(b[6])<<8 | uint64(b[7])
+	if u == 0 {
+		return NewProfileId()
+	}
+	return ProfileId(u), nil
+}
+
+// ParseProfileId parses a base62 string into a ProfileId.
+func ParseProfileId(s string) (ProfileId, bool) {
+	if len(s) == 0 || len(s) > 11 {
+		return 0, false
+	}
+	var v uint64
+	for i := 0; i < len(s); i++ {
+		d := base62Rev[s[i]]
+		if d == 0xFF {
+			return 0, false
+		}
+		v = v*62 + uint64(d)
+	}
+	return ProfileId(v), true
+}
+
+func encodeBase62(u uint64) string {
+	if u == 0 {
+		return "0"
+	}
+	var buf [11]byte
+	i := len(buf)
+	for u > 0 {
+		i--
+		buf[i] = base62Alphabet[u%62]
+		u /= 62
+	}
+	return string(buf[i:])
+}

pkg/profile/mutation-context.go

@@ -0,0 +1,21 @@
+package profile
+
+import (
+	"git.k6n.net/mats/go-cart-actor/pkg/actor"
+)
+
+// NewProfileMutationRegistry creates a mutation registry with all profile
+// mutation handlers registered.
+func NewProfileMutationRegistry() actor.MutationRegistry {
+	reg := actor.NewMutationRegistry()
+	reg.RegisterMutations(
+		actor.NewMutation(HandleSetProfile),
+		actor.NewMutation(HandleAddAddress),
+		actor.NewMutation(HandleUpdateAddress),
+		actor.NewMutation(HandleRemoveAddress),
+		actor.NewMutation(HandleLinkCart),
+		actor.NewMutation(HandleLinkCheckout),
+		actor.NewMutation(HandleLinkOrder),
+	)
+	return reg
+}

pkg/profile/mutation_address.go

@@ -0,0 +1,130 @@
+package profile
+
+import (
+	"fmt"
+
+	messages "git.k6n.net/mats/go-cart-actor/proto/profile"
+)
+
+// HandleAddAddress adds a new address to the user's address book.
+func HandleAddAddress(p *ProfileGrain, m *messages.AddAddress) error {
+	if m == nil {
+		return fmt.Errorf("AddAddress: nil payload")
+	}
+	if m.Address == nil {
+		return fmt.Errorf("AddAddress: address is required")
+	}
+
+	id := p.NextAddrId()
+	addr := protoToStored(id, m.Address)
+	if addr.IsDefaultShipping {
+		p.clearDefaultShipping()
+	}
+	if addr.IsDefaultBilling {
+		p.clearDefaultBilling()
+	}
+	p.Addresses = append(p.Addresses, *addr)
+	return nil
+}
+
+// HandleUpdateAddress updates an existing address (matched by id).
+func HandleUpdateAddress(p *ProfileGrain, m *messages.UpdateAddress) error {
+	if m == nil {
+		return fmt.Errorf("UpdateAddress: nil payload")
+	}
+	existing := p.findAddress(m.Id)
+	if existing == nil {
+		return fmt.Errorf("UpdateAddress: address %d not found", m.Id)
+	}
+	if m.Label != nil {
+		existing.Label = *m.Label
+	}
+	if m.FullName != nil {
+		existing.FullName = *m.FullName
+	}
+	if m.AddressLine1 != nil {
+		existing.AddressLine1 = *m.AddressLine1
+	}
+	if m.AddressLine2 != nil {
+		existing.AddressLine2 = *m.AddressLine2
+	}
+	if m.City != nil {
+		existing.City = *m.City
+	}
+	if m.State != nil {
+		existing.State = *m.State
+	}
+	if m.Zip != nil {
+		existing.Zip = *m.Zip
+	}
+	if m.Country != nil {
+		existing.Country = *m.Country
+	}
+	if m.Phone != nil {
+		existing.Phone = *m.Phone
+	}
+	if m.IsDefaultShipping != nil {
+		if *m.IsDefaultShipping {
+			p.clearDefaultShipping()
+		}
+		existing.IsDefaultShipping = *m.IsDefaultShipping
+	}
+	if m.IsDefaultBilling != nil {
+		if *m.IsDefaultBilling {
+			p.clearDefaultBilling()
+		}
+		existing.IsDefaultBilling = *m.IsDefaultBilling
+	}
+	return nil
+}
+
+// HandleRemoveAddress removes an address from the address book.
+func HandleRemoveAddress(p *ProfileGrain, m *messages.RemoveAddress) error {
+	if m == nil {
+		return fmt.Errorf("RemoveAddress: nil payload")
+	}
+	idx := -1
+	for i, a := range p.Addresses {
+		if a.Id == m.Id {
+			idx = i
+			break
+		}
+	}
+	if idx == -1 {
+		return fmt.Errorf("RemoveAddress: address %d not found", m.Id)
+	}
+	p.Addresses = append(p.Addresses[:idx], p.Addresses[idx+1:]...)
+	return nil
+}
+
+// clearDefaultShipping unsets IsDefaultShipping on all addresses.
+func (p *ProfileGrain) clearDefaultShipping() {
+	for i := range p.Addresses {
+		p.Addresses[i].IsDefaultShipping = false
+	}
+}
+
+// clearDefaultBilling unsets IsDefaultBilling on all addresses.
+func (p *ProfileGrain) clearDefaultBilling() {
+	for i := range p.Addresses {
+		p.Addresses[i].IsDefaultBilling = false
+	}
+}
+
+// protoToStored converts a proto Address to a stored StoredAddress.
+func protoToStored(id uint32, m *messages.Address) *StoredAddress {
+	return &StoredAddress{
+		Id:                id,
+		Label:             m.Label,
+		FullName:          m.FullName,
+		AddressLine1:      m.AddressLine1,
+		AddressLine2:      m.GetAddressLine2(),
+		City:              m.City,
+		State:             m.State,
+		Zip:               m.Zip,
+		Country:           m.Country,
+		Phone:             m.GetPhone(),
+		IsDefaultShipping: m.IsDefaultShipping,
+		IsDefaultBilling:  m.IsDefaultBilling,
+	}
+}

pkg/profile/mutation_links.go

@@ -0,0 +1,73 @@
+package profile
+
+import (
+	"fmt"
+
+	messages "git.k6n.net/mats/go-cart-actor/proto/profile"
+)
+
+// HandleLinkCart links a cart grain to this user profile.
+func HandleLinkCart(p *ProfileGrain, m *messages.LinkCart) error {
+	if m == nil {
+		return fmt.Errorf("LinkCart: nil payload")
+	}
+	if m.CartId == 0 {
+		return fmt.Errorf("LinkCart: cartId is required")
+	}
+	// Check for duplicate
+	for _, c := range p.Carts {
+		if c.CartId == m.CartId {
+			return nil // already linked; idempotent
+		}
+	}
+	p.Carts = append(p.Carts, LinkedCart{
+		CartId: m.CartId,
+		Label:  m.Label,
+	})
+	return nil
+}
+
+// HandleLinkCheckout links a checkout grain to this user profile.
+func HandleLinkCheckout(p *ProfileGrain, m *messages.LinkCheckout) error {
+	if m == nil {
+		return fmt.Errorf("LinkCheckout: nil payload")
+	}
+	if m.CheckoutId == 0 {
+		return fmt.Errorf("LinkCheckout: checkoutId is required")
+	}
+	// Check for duplicate
+	for _, ch := range p.Checkouts {
+		if ch.CheckoutId == m.CheckoutId {
+			return nil // already linked; idempotent
+		}
+	}
+	p.Checkouts = append(p.Checkouts, LinkedCheckout{
+		CheckoutId: m.CheckoutId,
+		CartId:     m.CartId,
+	})
+	return nil
+}
+
+// HandleLinkOrder links an order to this user profile.
+func HandleLinkOrder(p *ProfileGrain, m *messages.LinkOrder) error {
+	if m == nil {
+		return fmt.Errorf("LinkOrder: nil payload")
+	}
+	if m.OrderReference == "" {
+		return fmt.Errorf("LinkOrder: orderReference is required")
+	}
+	// Check for duplicate (by index so we can mutate)
+	for i := range p.Orders {
+		if p.Orders[i].OrderReference == m.OrderReference {
+			// Update status snapshot
+			p.Orders[i].Status = m.Status
+			return nil
+		}
+	}
+	p.Orders = append(p.Orders, LinkedOrder{
+		OrderReference: m.OrderReference,
+		CartId:         m.CartId,
+		Status:         m.Status,
+	})
+	return nil
+}

pkg/profile/mutation_set_profile.go

@@ -0,0 +1,33 @@
+package profile
+
+import (
+	"fmt"
+
+	messages "git.k6n.net/mats/go-cart-actor/proto/profile"
+)
+
+// HandleSetProfile updates the user's core profile information.
+func HandleSetProfile(p *ProfileGrain, m *messages.SetProfile) error {
+	if m == nil {
+		return fmt.Errorf("SetProfile: nil payload")
+	}
+	if m.Name != nil {
+		p.Name = *m.Name
+	}
+	if m.Email != nil {
+		p.Email = *m.Email
+	}
+	if m.Phone != nil {
+		p.Phone = *m.Phone
+	}
+	if m.Language != nil {
+		p.Language = *m.Language
+	}
+	if m.Currency != nil {
+		p.Currency = *m.Currency
+	}
+	if m.AvatarUrl != nil {
+		p.AvatarUrl = *m.AvatarUrl
+	}
+	return nil
+}

pkg/profile/profile-grain.go

@@ -0,0 +1,108 @@
+// Package profile implements a user-profile actor grain (same event-driven
+// framework as the cart, checkout, and order grains). Mutations are the proto
+// messages in proto/profile; the grain's event log is the source of truth and
+// ProfileGrain is the projection rebuilt by replaying them.
+package profile
+
+import (
+	"encoding/json"
+	"sync"
+	"time"
+)
+
+// LinkedCart records a cart id linked to this profile.
+type LinkedCart struct {
+	CartId uint64 `json:"cartId"`
+	Label  string `json:"label,omitempty"`
+}
+
+// LinkedCheckout records a checkout id linked to this profile.
+type LinkedCheckout struct {
+	CheckoutId uint64 `json:"checkoutId"`
+	CartId     uint64 `json:"cartId"`
+}
+
+// LinkedOrder records an order linked to this profile.
+type LinkedOrder struct {
+	OrderReference string `json:"orderReference"`
+	CartId         uint64 `json:"cartId"`
+	Status         string `json:"status,omitempty"`
+}
+
+// StoredAddress is a saved address in the user's address book.
+type StoredAddress struct {
+	Id                uint32 `json:"id"`
+	Label             string `json:"label,omitempty"`
+	FullName          string `json:"fullName,omitempty"`
+	AddressLine1      string `json:"addressLine1"`
+	AddressLine2      string `json:"addressLine2,omitempty"`
+	City              string `json:"city"`
+	State             string `json:"state,omitempty"`
+	Zip               string `json:"zip"`
+	Country           string `json:"country"`
+	Phone             string `json:"phone,omitempty"`
+	IsDefaultShipping bool   `json:"isDefaultShipping,omitempty"`
+	IsDefaultBilling  bool   `json:"isDefaultBilling,omitempty"`
+}
+
+// ProfileGrain is the projected current state of a user profile. It implements
+// actor.Grain[ProfileGrain].
+type ProfileGrain struct {
+	mu         sync.RWMutex
+	lastAccess time.Time
+	lastChange time.Time
+	nextAddrId uint32
+
+	Id       uint64 `json:"id"`
+	Name     string `json:"name,omitempty"`
+	Email    string `json:"email,omitempty"`
+	Phone    string `json:"phone,omitempty"`
+	Language string `json:"language,omitempty"`
+	Currency string `json:"currency,omitempty"`
+
+	AvatarUrl string           `json:"avatarUrl,omitempty"`
+	Carts     []LinkedCart     `json:"carts,omitempty"`
+	Checkouts []LinkedCheckout `json:"checkouts,omitempty"`
+	Orders    []LinkedOrder    `json:"orders,omitempty"`
+	Addresses []StoredAddress  `json:"addresses,omitempty"`
+}
+
+// NewProfileGrain returns an empty profile grain for id.
+func NewProfileGrain(id uint64, ts time.Time) *ProfileGrain {
+	return &ProfileGrain{
+		Id:         id,
+		lastAccess: ts,
+		lastChange: ts,
+	}
+}
+
+// --- actor.Grain[ProfileGrain] ---
+
+func (p *ProfileGrain) GetId() uint64 { return p.Id }
+
+func (p *ProfileGrain) GetLastAccess() time.Time { return p.lastAccess }
+
+func (p *ProfileGrain) GetLastChange() time.Time { return p.lastChange }
+
+func (p *ProfileGrain) GetCurrentState() (*ProfileGrain, error) {
+	p.lastAccess = time.Now()
+	return p, nil
+}
+
+func (p *ProfileGrain) GetState() ([]byte, error) { return json.Marshal(p) }
+
+// NextAddrId returns the next address id and advances the counter.
+func (p *ProfileGrain) NextAddrId() uint32 {
+	p.nextAddrId++
+	return p.nextAddrId
+}
+
+// findAddress returns a pointer to the address with the given id, or nil.
+func (p *ProfileGrain) findAddress(id uint32) *StoredAddress {
+	for i := range p.Addresses {
+		if p.Addresses[i].Id == id {
+			return &p.Addresses[i]
+		}
+	}
+	return nil
+}

pkg/profile/profile_test.go

@@ -0,0 +1,633 @@
+package profile
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"git.k6n.net/mats/go-cart-actor/pkg/actor"
+	messages "git.k6n.net/mats/go-cart-actor/proto/profile"
+	"google.golang.org/protobuf/proto"
+)
+
+// --- helpers (mirroring order/order_test.go) ---
+
+func apply(t *testing.T, reg actor.MutationRegistry, g *ProfileGrain, msg proto.Message) error {
+	t.Helper()
+	results, err := reg.Apply(context.Background(), g, msg)
+	if err != nil {
+		return err
+	}
+	if len(results) != 1 {
+		t.Fatalf("expected 1 result, got %d", len(results))
+	}
+	return results[0].Error
+}
+
+func mustApply(t *testing.T, reg actor.MutationRegistry, g *ProfileGrain, msg proto.Message) {
+	t.Helper()
+	if err := apply(t, reg, g, msg); err != nil {
+		t.Fatalf("apply %T: %v", msg, err)
+	}
+}
+
+func newRegistry() actor.MutationRegistry {
+	return NewProfileMutationRegistry()
+}
+
+// strPtr is a helper for proto optional string fields.
+func strPtr(s string) *string { return &s }
+func boolPtr(b bool) *bool    { return &b }
+
+// --- SetProfile ---
+
+func TestSetProfileAllFields(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(1, time.Now())
+
+	mustApply(t, reg, g, &messages.SetProfile{
+		Name:     strPtr("Jane Doe"),
+		Email:    strPtr("jane@example.com"),
+		Phone:    strPtr("+46 70 123 45 67"),
+		Language: strPtr("sv"),
+		Currency: strPtr("SEK"),
+		AvatarUrl: strPtr("https://cdn.example.com/avatar/jane.jpg"),
+	})
+
+	if g.Name != "Jane Doe" {
+		t.Fatalf("Name = %q, want %q", g.Name, "Jane Doe")
+	}
+	if g.Email != "jane@example.com" {
+		t.Fatalf("Email = %q, want %q", g.Email, "jane@example.com")
+	}
+	if g.Phone != "+46 70 123 45 67" {
+		t.Fatalf("Phone = %q, want %q", g.Phone, "+46 70 123 45 67")
+	}
+	if g.Language != "sv" {
+		t.Fatalf("Language = %q, want %q", g.Language, "sv")
+	}
+	if g.Currency != "SEK" {
+		t.Fatalf("Currency = %q, want %q", g.Currency, "SEK")
+	}
+	if g.AvatarUrl != "https://cdn.example.com/avatar/jane.jpg" {
+		t.Fatalf("AvatarUrl = %q, want %q", g.AvatarUrl, "https://cdn.example.com/avatar/jane.jpg")
+	}
+}
+
+func TestSetProfilePartialUpdate(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(2, time.Now())
+	g.Name = "Old Name"
+	g.Email = "old@example.com"
+
+	mustApply(t, reg, g, &messages.SetProfile{
+		Email: strPtr("updated@example.com"),
+	})
+
+	if g.Name != "Old Name" {
+		t.Fatalf("Name should be unchanged, got %q", g.Name)
+	}
+	if g.Email != "updated@example.com" {
+		t.Fatalf("Email = %q, want %q", g.Email, "updated@example.com")
+	}
+}
+
+func TestSetProfileNilMessage(t *testing.T) {
+	g := NewProfileGrain(3, time.Now())
+	if err := HandleSetProfile(g, nil); err == nil {
+		t.Fatal("expected error for nil SetProfile, got nil")
+	}
+}
+
+// --- AddAddress ---
+
+func addrProto(id *uint32) *messages.Address {
+	return &messages.Address{
+		Label:        "Home",
+		FullName:     "Jane Doe",
+		AddressLine1: "Storgatan 1",
+		City:         "Stockholm",
+		State:        "Stockholm",
+		Zip:          "111 22",
+		Country:      "SE",
+		Phone:        strPtr("+46 70 123 45 67"),
+	}
+}
+
+func TestAddAddress(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(10, time.Now())
+
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+
+	if len(g.Addresses) != 1 {
+		t.Fatalf("expected 1 address, got %d", len(g.Addresses))
+	}
+	a := g.Addresses[0]
+	if a.Id != 1 {
+		t.Fatalf("expected address id 1, got %d", a.Id)
+	}
+	if a.Label != "Home" {
+		t.Fatalf("Label = %q, want %q", a.Label, "Home")
+	}
+	if a.City != "Stockholm" {
+		t.Fatalf("City = %q, want %q", a.City, "Stockholm")
+	}
+	if a.Phone != "+46 70 123 45 67" {
+		t.Fatalf("Phone = %q, want %q", a.Phone, "+46 70 123 45 67")
+	}
+}
+
+func TestAddAddressIncrementsId(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(11, time.Now())
+
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+
+	if len(g.Addresses) != 3 {
+		t.Fatalf("expected 3 addresses, got %d", len(g.Addresses))
+	}
+	for i, a := range g.Addresses {
+		if want := uint32(i + 1); a.Id != want {
+			t.Fatalf("address %d id = %d, want %d", i, a.Id, want)
+		}
+	}
+}
+
+func TestAddAddressDefaultShippingClearsOthers(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(12, time.Now())
+
+	// Add two non-default addresses
+	addr1 := addrProto(nil)
+	addr1.IsDefaultShipping = false
+	addr1.IsDefaultBilling = false
+	mustApply(t, reg, g, &messages.AddAddress{Address: addr1})
+
+	addr2 := addrProto(nil)
+	addr2.IsDefaultShipping = false
+	addr2.IsDefaultBilling = false
+	mustApply(t, reg, g, &messages.AddAddress{Address: addr2})
+
+	// Add a default-shipping address — should clear the previous ones
+	addr3 := addrProto(nil)
+	addr3.IsDefaultShipping = true
+	mustApply(t, reg, g, &messages.AddAddress{Address: addr3})
+
+	if len(g.Addresses) != 3 {
+		t.Fatalf("expected 3 addresses, got %d", len(g.Addresses))
+	}
+	if !g.Addresses[2].IsDefaultShipping {
+		t.Fatal("expected address 3 to be default shipping")
+	}
+	for i := 0; i < 2; i++ {
+		if g.Addresses[i].IsDefaultShipping {
+			t.Fatalf("address %d should not be default shipping", i)
+		}
+	}
+}
+
+func TestAddAddressNil(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(13, time.Now())
+
+	if err := apply(t, reg, g, &messages.AddAddress{Address: nil}); err == nil {
+		t.Fatal("expected error for nil address, got nil")
+	}
+}
+
+// --- UpdateAddress ---
+
+func TestUpdateAddressAllFields(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(20, time.Now())
+
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+
+	mustApply(t, reg, g, &messages.UpdateAddress{
+		Id:          1,
+		Label:       strPtr("Work"),
+		FullName:    strPtr("Jane Doe Updated"),
+		AddressLine1: strPtr("Drottninggatan 10"),
+		City:        strPtr("Göteborg"),
+		State:       strPtr("Västra Götaland"),
+		Zip:         strPtr("411 03"),
+		Country:     strPtr("SE"),
+		Phone:       strPtr("+46 70 987 65 43"),
+	})
+
+	a := g.Addresses[0]
+	if a.Label != "Work" {
+		t.Fatalf("Label = %q, want %q", a.Label, "Work")
+	}
+	if a.City != "Göteborg" {
+		t.Fatalf("City = %q, want %q", a.City, "Göteborg")
+	}
+	if a.Phone != "+46 70 987 65 43" {
+		t.Fatalf("Phone = %q, want %q", a.Phone, "+46 70 987 65 43")
+	}
+}
+
+func TestUpdateAddressPartialFields(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(21, time.Now())
+
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+
+	// Update only the label
+	mustApply(t, reg, g, &messages.UpdateAddress{
+		Id:    1,
+		Label: strPtr("Summer Home"),
+	})
+
+	a := g.Addresses[0]
+	if a.Label != "Summer Home" {
+		t.Fatalf("Label = %q, want %q", a.Label, "Summer Home")
+	}
+	if a.City != "Stockholm" {
+		t.Fatalf("City should be unchanged, got %q", a.City)
+	}
+}
+
+func TestUpdateAddressNotFound(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(22, time.Now())
+
+	if err := apply(t, reg, g, &messages.UpdateAddress{Id: 999, Label: strPtr("Nowhere")}); err == nil {
+		t.Fatal("expected error for non-existent address, got nil")
+	}
+}
+
+func TestUpdateAddressDefaultShippingClearsOthers(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(23, time.Now())
+
+	addr1 := addrProto(nil)
+	addr1.IsDefaultShipping = true
+	mustApply(t, reg, g, &messages.AddAddress{Address: addr1})
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+
+	// Update address 2 to be default shipping — should clear address 1
+	mustApply(t, reg, g, &messages.UpdateAddress{
+		Id:              2,
+		IsDefaultShipping: boolPtr(true),
+	})
+
+	if !g.Addresses[1].IsDefaultShipping {
+		t.Fatal("expected address 2 to be default shipping")
+	}
+	if g.Addresses[0].IsDefaultShipping {
+		t.Fatal("address 1 should no longer be default shipping")
+	}
+}
+
+// --- RemoveAddress ---
+
+func TestRemoveAddress(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(30, time.Now())
+
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+
+	mustApply(t, reg, g, &messages.RemoveAddress{Id: 2})
+
+	if len(g.Addresses) != 2 {
+		t.Fatalf("expected 2 addresses after removal, got %d", len(g.Addresses))
+	}
+	if g.Addresses[0].Id != 1 {
+		t.Fatalf("expected address id 1 at index 0, got %d", g.Addresses[0].Id)
+	}
+	if g.Addresses[1].Id != 3 {
+		t.Fatalf("expected address id 3 at index 1, got %d", g.Addresses[1].Id)
+	}
+}
+
+func TestRemoveAddressNotFound(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(31, time.Now())
+
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+
+	if err := apply(t, reg, g, &messages.RemoveAddress{Id: 99}); err == nil {
+		t.Fatal("expected error for removing non-existent address, got nil")
+	}
+}
+
+func TestRemoveAddressLastElement(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(32, time.Now())
+
+	mustApply(t, reg, g, &messages.AddAddress{Address: addrProto(nil)})
+	mustApply(t, reg, g, &messages.RemoveAddress{Id: 1})
+
+	if len(g.Addresses) != 0 {
+		t.Fatalf("expected 0 addresses, got %d", len(g.Addresses))
+	}
+}
+
+// --- LinkCart ---
+
+func TestLinkCart(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(40, time.Now())
+
+	mustApply(t, reg, g, &messages.LinkCart{
+		CartId: 1001,
+		Label:  "current cart",
+	})
+
+	if len(g.Carts) != 1 {
+		t.Fatalf("expected 1 linked cart, got %d", len(g.Carts))
+	}
+	if g.Carts[0].CartId != 1001 {
+		t.Fatalf("CartId = %d, want %d", g.Carts[0].CartId, 1001)
+	}
+	if g.Carts[0].Label != "current cart" {
+		t.Fatalf("Label = %q, want %q", g.Carts[0].Label, "current cart")
+	}
+}
+
+func TestLinkCartMultiple(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(41, time.Now())
+
+	mustApply(t, reg, g, &messages.LinkCart{CartId: 1, Label: "first"})
+	mustApply(t, reg, g, &messages.LinkCart{CartId: 2, Label: "second"})
+
+	if len(g.Carts) != 2 {
+		t.Fatalf("expected 2 linked carts, got %d", len(g.Carts))
+	}
+}
+
+func TestLinkCartDuplicateIdempotent(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(42, time.Now())
+
+	mustApply(t, reg, g, &messages.LinkCart{CartId: 1001})
+	mustApply(t, reg, g, &messages.LinkCart{CartId: 1001}) // same cart again
+
+	if len(g.Carts) != 1 {
+		t.Fatalf("expected 1 linked cart (idempotent), got %d", len(g.Carts))
+	}
+}
+
+func TestLinkCartMissingId(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(43, time.Now())
+
+	if err := apply(t, reg, g, &messages.LinkCart{CartId: 0}); err == nil {
+		t.Fatal("expected error for zero cartId, got nil")
+	}
+}
+
+// --- LinkCheckout ---
+
+func TestLinkCheckout(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(50, time.Now())
+
+	mustApply(t, reg, g, &messages.LinkCheckout{
+		CheckoutId: 2001,
+		CartId:     1001,
+	})
+
+	if len(g.Checkouts) != 1 {
+		t.Fatalf("expected 1 linked checkout, got %d", len(g.Checkouts))
+	}
+	if g.Checkouts[0].CheckoutId != 2001 {
+		t.Fatalf("CheckoutId = %d, want %d", g.Checkouts[0].CheckoutId, 2001)
+	}
+	if g.Checkouts[0].CartId != 1001 {
+		t.Fatalf("CartId = %d, want %d", g.Checkouts[0].CartId, 1001)
+	}
+}
+
+func TestLinkCheckoutMultiple(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(51, time.Now())
+
+	mustApply(t, reg, g, &messages.LinkCheckout{CheckoutId: 1, CartId: 10})
+	mustApply(t, reg, g, &messages.LinkCheckout{CheckoutId: 2, CartId: 20})
+
+	if len(g.Checkouts) != 2 {
+		t.Fatalf("expected 2 linked checkouts, got %d", len(g.Checkouts))
+	}
+}
+
+func TestLinkCheckoutDuplicateIdempotent(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(52, time.Now())
+
+	mustApply(t, reg, g, &messages.LinkCheckout{CheckoutId: 2001, CartId: 1001})
+	mustApply(t, reg, g, &messages.LinkCheckout{CheckoutId: 2001, CartId: 1001})
+
+	if len(g.Checkouts) != 1 {
+		t.Fatalf("expected 1 linked checkout (idempotent), got %d", len(g.Checkouts))
+	}
+}
+
+func TestLinkCheckoutMissingId(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(53, time.Now())
+
+	if err := apply(t, reg, g, &messages.LinkCheckout{CheckoutId: 0}); err == nil {
+		t.Fatal("expected error for zero checkoutId, got nil")
+	}
+}
+
+// --- LinkOrder ---
+
+func TestLinkOrder(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(60, time.Now())
+
+	mustApply(t, reg, g, &messages.LinkOrder{
+		OrderReference: "ORD-001",
+		CartId:         1001,
+		Status:         "pending",
+	})
+
+	if len(g.Orders) != 1 {
+		t.Fatalf("expected 1 linked order, got %d", len(g.Orders))
+	}
+	if g.Orders[0].OrderReference != "ORD-001" {
+		t.Fatalf("OrderReference = %q, want %q", g.Orders[0].OrderReference, "ORD-001")
+	}
+	if g.Orders[0].CartId != 1001 {
+		t.Fatalf("CartId = %d, want %d", g.Orders[0].CartId, 1001)
+	}
+	if g.Orders[0].Status != "pending" {
+		t.Fatalf("Status = %q, want %q", g.Orders[0].Status, "pending")
+	}
+}
+
+func TestLinkOrderUpdatesStatusOnDuplicate(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(61, time.Now())
+
+	mustApply(t, reg, g, &messages.LinkOrder{
+		OrderReference: "ORD-001",
+		CartId:         1001,
+		Status:         "pending",
+	})
+	mustApply(t, reg, g, &messages.LinkOrder{
+		OrderReference: "ORD-001",
+		CartId:         1001,
+		Status:         "captured",
+	})
+
+	if len(g.Orders) != 1 {
+		t.Fatalf("expected 1 linked order (idempotent), got %d", len(g.Orders))
+	}
+	if g.Orders[0].Status != "captured" {
+		t.Fatalf("Status = %q, want %q", g.Orders[0].Status, "captured")
+	}
+}
+
+func TestLinkOrderMissingReference(t *testing.T) {
+	reg := newRegistry()
+	g := NewProfileGrain(62, time.Now())
+
+	if err := apply(t, reg, g, &messages.LinkOrder{OrderReference: "", CartId: 1001}); err == nil {
+		t.Fatal("expected error for empty orderReference, got nil")
+	}
+}
+
+// --- Nil message edge cases (call handlers directly with typed nil pointers;
+//     the registry silently skips typed-nil messages, so Apply does not reach
+//     the handler and we must test the handler in isolation) ---
+
+func TestNilMessages(t *testing.T) {
+	tests := []struct {
+		name string
+		err  error
+	}{
+		{"nil SetProfile", HandleSetProfile(NewProfileGrain(70, time.Now()), (*messages.SetProfile)(nil))},
+		{"nil AddAddress", HandleAddAddress(NewProfileGrain(70, time.Now()), (*messages.AddAddress)(nil))},
+		{"nil UpdateAddress", HandleUpdateAddress(NewProfileGrain(70, time.Now()), (*messages.UpdateAddress)(nil))},
+		{"nil RemoveAddress", HandleRemoveAddress(NewProfileGrain(70, time.Now()), (*messages.RemoveAddress)(nil))},
+		{"nil LinkCart", HandleLinkCart(NewProfileGrain(70, time.Now()), (*messages.LinkCart)(nil))},
+		{"nil LinkCheckout", HandleLinkCheckout(NewProfileGrain(70, time.Now()), (*messages.LinkCheckout)(nil))},
+		{"nil LinkOrder", HandleLinkOrder(NewProfileGrain(70, time.Now()), (*messages.LinkOrder)(nil))},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.err == nil {
+				t.Fatal("expected error for nil message, got nil")
+			}
+		})
+	}
+}
+
+// --- Event-sourced replay test (mirroring order/order_test.go) ---
+
+func TestEventSourcedReplay(t *testing.T) {
+	reg := newRegistry()
+	storage := actor.NewDiskStorage[ProfileGrain](t.TempDir(), reg)
+
+	const id uint64 = 100
+	g := NewProfileGrain(id, time.Now())
+
+	events := []proto.Message{
+		&messages.SetProfile{
+			Name:  strPtr("Jane Doe"),
+			Email: strPtr("jane@example.com"),
+		},
+		&messages.AddAddress{Address: addrProto(nil)},
+		&messages.LinkCart{CartId: 1001, Label: "current"},
+		&messages.LinkCheckout{CheckoutId: 2001, CartId: 1001},
+		&messages.LinkOrder{OrderReference: "ORD-001", CartId: 1001, Status: "pending"},
+		&messages.AddAddress{
+			Address: &messages.Address{
+				Label:        "Work",
+				FullName:     "Jane Doe",
+				AddressLine1: "Kungsgatan 5",
+				City:         "Malmö",
+				State:        "Skåne",
+				Zip:          "211 11",
+				Country:      "SE",
+			},
+		},
+		&messages.UpdateAddress{
+			Id:    1,
+			Label: strPtr("Home (Updated)"),
+		},
+		&messages.LinkOrder{OrderReference: "ORD-002", CartId: 1002, Status: "captured"},
+	}
+
+	for _, e := range events {
+		mustApply(t, reg, g, e)
+		if err := storage.AppendMutations(id, e); err != nil {
+			t.Fatalf("append: %v", err)
+		}
+	}
+
+	// Verify initial grain state before replay.
+	if g.Name != "Jane Doe" {
+		t.Fatalf("Name = %q, want %q", g.Name, "Jane Doe")
+	}
+	if len(g.Addresses) != 2 {
+		t.Fatalf("expected 2 addresses, got %d", len(g.Addresses))
+	}
+	if g.Addresses[0].Label != "Home (Updated)" {
+		t.Fatalf("first address label = %q, want %q", g.Addresses[0].Label, "Home (Updated)")
+	}
+	if len(g.Carts) != 1 {
+		t.Fatalf("expected 1 cart, got %d", len(g.Carts))
+	}
+	if len(g.Checkouts) != 1 {
+		t.Fatalf("expected 1 checkout, got %d", len(g.Checkouts))
+	}
+	if len(g.Orders) != 2 {
+		t.Fatalf("expected 2 orders, got %d", len(g.Orders))
+	}
+	if g.Orders[1].Status != "captured" {
+		t.Fatalf("second order status = %q, want %q", g.Orders[1].Status, "captured")
+	}
+
+	// Replay into a brand-new grain and compare the projection.
+	replayed := NewProfileGrain(id, time.Now())
+	if err := storage.LoadEvents(context.Background(), id, replayed); err != nil {
+		t.Fatalf("replay: %v", err)
+	}
+
+	if replayed.Name != g.Name {
+		t.Fatalf("replayed Name = %q, want %q", replayed.Name, g.Name)
+	}
+	if replayed.Email != g.Email {
+		t.Fatalf("replayed Email = %q, want %q", replayed.Email, g.Email)
+	}
+	if len(replayed.Addresses) != len(g.Addresses) {
+		t.Fatalf("replayed addresses = %d, want %d", len(replayed.Addresses), len(g.Addresses))
+	}
+	if replayed.Addresses[0].Label != g.Addresses[0].Label {
+		t.Fatalf("replayed first address label = %q, want %q", replayed.Addresses[0].Label, g.Addresses[0].Label)
+	}
+	if replayed.Addresses[0].Id != g.Addresses[0].Id {
+		t.Fatalf("replayed first address id = %d, want %d", replayed.Addresses[0].Id, g.Addresses[0].Id)
+	}
+	// Address book: second address should have been added AFTER the update to
+	// address 1, so its id is 2 and it should match the original.
+	if replayed.Addresses[1].City != g.Addresses[1].City {
+		t.Fatalf("replayed second address city = %q, want %q", replayed.Addresses[1].City, g.Addresses[1].City)
+	}
+	if len(replayed.Carts) != len(g.Carts) {
+		t.Fatalf("replayed carts = %d, want %d", len(replayed.Carts), len(g.Carts))
+	}
+	if len(replayed.Checkouts) != len(g.Checkouts) {
+		t.Fatalf("replayed checkouts = %d, want %d", len(replayed.Checkouts), len(g.Checkouts))
+	}
+	if len(replayed.Orders) != len(g.Orders) {
+		t.Fatalf("replayed orders = %d, want %d", len(replayed.Orders), len(g.Orders))
+	}
+	if replayed.Orders[0].Status != g.Orders[0].Status {
+		t.Fatalf("replayed first order status = %q, want %q", replayed.Orders[0].Status, g.Orders[0].Status)
+	}
+	if replayed.Orders[1].Status != g.Orders[1].Status {
+		t.Fatalf("replayed second order status = %q, want %q", replayed.Orders[1].Status, g.Orders[1].Status)
+	}
+}