Merge pull request 'Implement phone number validation for customer and user registration and updates' (#35) from Phone-Uniqueness into develop

Reviewed-on: https://repo.ravanertebat.com/TM/tm_back/pulls/35

internal/customer/errors.go

@@ -1,7 +1,42 @@
 package customer
 
-import "errors"
+import (
+	"errors"
 
-var (
-	ErrCustomerNotFound = errors.New("customer not found")
+	orm "tm/pkg/mongo"
 )
+
+var ErrCustomerNotFound = errors.New("customer not found")
+
+func mapCustomerWriteError(err error) error {
+	if err == nil || !orm.IsDuplicateKeyError(err) {
+		return err
+	}
+	switch {
+	case orm.DuplicateKeyMatchesField(err, "phone"):
+		return errors.New("customer with this phone number already exists")
+	case orm.DuplicateKeyMatchesField(err, "email"):
+		return errors.New("customer with this email already exists")
+	case orm.DuplicateKeyMatchesField(err, "username"):
+		return errors.New("customer with this username already exists")
+	default:
+		return err
+	}
+}
+
+func isCustomerConflictError(err error) bool {
+	if err == nil {
+		return false
+	}
+	switch err.Error() {
+	case "customer with this phone number already exists",
+		"customer with this email already exists",
+		"customer with this username already exists",
+		"company with this name already exists",
+		"company with this registration number already exists",
+		"company with this tax ID already exists":
+		return true
+	default:
+		return false
+	}
+}

internal/customer/handler.go

@@ -53,11 +53,7 @@ func (h *Handler) CreateCustomer(c echo.Context) error {
 
 	customer, err := h.service.Register(c.Request().Context(), form)
 	if err != nil {
-		if err.Error() == "customer with this email already exists" ||
-			err.Error() == "customer with this username already exists" ||
-			err.Error() == "company with this name already exists" ||
-			err.Error() == "company with this registration number already exists" ||
-			err.Error() == "company with this tax ID already exists" {
+		if isCustomerConflictError(err) {
 			return response.Conflict(c, err.Error())
 		}
 		if strings.HasPrefix(err.Error(), "invalid company ID") || err.Error() == "invalid username format" {
@@ -126,11 +122,7 @@ func (h *Handler) UpdateCustomer(c echo.Context) error {
 		if err.Error() == "customer not found" {
 			return response.NotFound(c, "Customer not found")
 		}
-		if err.Error() == "customer with this email already exists" ||
-			err.Error() == "customer with this username already exists" ||
-			err.Error() == "company with this name already exists" ||
-			err.Error() == "company with this registration number already exists" ||
-			err.Error() == "company with this tax ID already exists" {
+		if isCustomerConflictError(err) {
 			return response.Conflict(c, err.Error())
 		}
 		if strings.HasPrefix(err.Error(), "invalid company ID") {

internal/customer/repository.go

@@ -25,6 +25,7 @@ type Repository interface {
 	GetByID(ctx context.Context, id string) (*Customer, error)
 	GetByEmail(ctx context.Context, email string) (*Customer, error)
 	GetByUsername(ctx context.Context, username string) (*Customer, error)
+	GetByPhone(ctx context.Context, phone string) (*Customer, error)
 	GetByIDs(ctx context.Context, ids []string) ([]Customer, error)
 	GetByRole(ctx context.Context, role CustomerRole) ([]Customer, error)
 	GetByCompanies(ctx context.Context, companies []string) ([]Customer, error)
@@ -50,6 +51,8 @@ func NewRepository(mongoManager *orm.ConnectionManager, logger logger.Logger) Re
 	indexes := []orm.Index{
 		*orm.CreateUniqueIndex("username_idx", bson.D{{Key: "username", Value: 1}}),
 		*orm.CreateTextIndex("search_idx", "email", "username"),
+		*orm.CreateUniqueIndex("phone_idx", bson.D{{Key: "phone", Value: 1}}).
+			WithPartialFilterExpression(bson.M{"phone": bson.M{"$type": "string", "$ne": ""}}),
 	}
 
 	// Create indexes
@@ -166,6 +169,24 @@ func (r *customerRepository) GetByEmail(ctx context.Context, email string) (*Cus
 	return customer, nil
 }
 
+// GetByPhone retrieves a customer by phone number
+func (r *customerRepository) GetByPhone(ctx context.Context, phone string) (*Customer, error) {
+	filter := bson.M{"phone": phone}
+	customer, err := r.ormRepo.FindOne(ctx, filter)
+	if err != nil {
+		if errors.Is(err, orm.ErrDocumentNotFound) {
+			return nil, ErrCustomerNotFound
+		}
+		r.logger.Error("Failed to get customer by phone", map[string]interface{}{
+			"error": err.Error(),
+			"phone": phone,
+		})
+		return nil, err
+	}
+
+	return customer, nil
+}
+
 // GetByUsername retrieves a customer by username
 func (r *customerRepository) GetByUsername(ctx context.Context, username string) (*Customer, error) {
 	filter := bson.M{"username": username}

internal/customer/service.go

@@ -95,6 +95,13 @@ func (s *customerService) Register(ctx context.Context, form *CreateCustomerForm
 		return nil, errors.New("customer with this username already exists")
 	}
 
+	if form.Phone != nil && *form.Phone != "" {
+		existingCustomer, _ = s.repository.GetByPhone(ctx, *form.Phone)
+		if existingCustomer != nil {
+			return nil, errors.New("customer with this phone number already exists")
+		}
+	}
+
 	// Check validator
 	if !s.validator.IsValidUsername(form.Username) {
 		return nil, errors.New("invalid username format")
@@ -149,6 +156,9 @@ func (s *customerService) Register(ctx context.Context, form *CreateCustomerForm
 	// Save to database
 	err = s.repository.Register(ctx, customer)
 	if err != nil {
+		if mapped := mapCustomerWriteError(err); mapped != err {
+			return nil, mapped
+		}
 		s.logger.Error("Failed to create customer", map[string]interface{}{
 			"error":    err.Error(),
 			"email":    form.Email,
@@ -373,6 +383,12 @@ func (s *customerService) Update(ctx context.Context, id string, form *UpdateCus
 	}
 
 	if form.Phone != nil && (customer.Phone == nil || *form.Phone != *customer.Phone) {
+		if *form.Phone != "" {
+			existingCustomer, _ := s.repository.GetByPhone(ctx, *form.Phone)
+			if existingCustomer != nil && existingCustomer.ID.Hex() != id {
+				return nil, errors.New("customer with this phone number already exists")
+			}
+		}
 		customer.Phone = form.Phone
 		infoChanged = true
 	}
@@ -411,6 +427,9 @@ func (s *customerService) Update(ctx context.Context, id string, form *UpdateCus
 	// Update in database
 	err = s.repository.Update(ctx, customer)
 	if err != nil {
+		if mapped := mapCustomerWriteError(err); mapped != err {
+			return nil, mapped
+		}
 		s.logger.Error("Failed to update customer", map[string]interface{}{
 			"error":       err.Error(),
 			"customer_id": id,

internal/user/errors.go

@@ -1,7 +1,37 @@
 package user
 
-import "errors"
+import (
+	"errors"
 
-var (
-	ErrUserNotFound = errors.New("user not found")
+	orm "tm/pkg/mongo"
 )
+
+var ErrUserNotFound = errors.New("user not found")
+
+func mapUserWriteError(err error) error {
+	if err == nil || !orm.IsDuplicateKeyError(err) {
+		return err
+	}
+	switch {
+	case orm.DuplicateKeyMatchesField(err, "phone"):
+		return errors.New("phone number already exists")
+	case orm.DuplicateKeyMatchesField(err, "email"):
+		return errors.New("email already exists")
+	case orm.DuplicateKeyMatchesField(err, "username"):
+		return errors.New("username already exists")
+	default:
+		return err
+	}
+}
+
+func isUserConflictError(err error) bool {
+	if err == nil {
+		return false
+	}
+	switch err.Error() {
+	case "phone number already exists", "email already exists", "username already exists":
+		return true
+	default:
+		return false
+	}
+}

internal/user/handler.go

@@ -170,6 +170,9 @@ func (h *Handler) UpdateProfile(c echo.Context) error {
 
 	user, err := h.service.Update(c.Request().Context(), userID, form)
 	if err != nil {
+		if isUserConflictError(err) {
+			return response.Conflict(c, err.Error())
+		}
 		return response.BadRequest(c, err.Error(), "")
 	}
 
@@ -274,6 +277,9 @@ func (h *Handler) CreateUser(c echo.Context) error {
 	// Call service
 	user, err := h.service.Register(c.Request().Context(), form)
 	if err != nil {
+		if isUserConflictError(err) {
+			return response.Conflict(c, err.Error())
+		}
 		return response.BadRequest(c, err.Error(), "")
 	}
 
@@ -386,6 +392,9 @@ func (h *Handler) UpdateUser(c echo.Context) error {
 	// Call service
 	user, err := h.service.Update(c.Request().Context(), idStr, form)
 	if err != nil {
+		if isUserConflictError(err) {
+			return response.Conflict(c, err.Error())
+		}
 		return response.BadRequest(c, err.Error(), "")
 	}
 

internal/user/repository.go

@@ -22,6 +22,7 @@ type Repository interface {
 	UpdatePasswordReset(ctx context.Context, id, hashedPassword, updatedBy string) error
 	GetByEmail(ctx context.Context, email string) (*User, error)
 	GetByUsername(ctx context.Context, username string) (*User, error)
+	GetByPhone(ctx context.Context, phone string) (*User, error)
 	GetByIDs(ctx context.Context, userIDs []string) ([]User, error)
 	Search(ctx context.Context, form *SearchUsersForm, pagination *response.Pagination) (*orm.PaginatedResult[User], error)
 }
@@ -38,6 +39,8 @@ func NewRepository(mongoManager *orm.ConnectionManager, logger logger.Logger) Re
 	// Create indexes using the ORM's index management
 	indexes := []orm.Index{
 		*orm.CreateTextIndex("search_idx", "full_name", "email", "username"),
+		*orm.CreateUniqueIndex("phone_idx", bson.D{{Key: "phone", Value: 1}}).
+			WithPartialFilterExpression(bson.M{"phone": bson.M{"$type": "string", "$ne": ""}}),
 	}
 
 	// Create indexes
@@ -250,6 +253,23 @@ func (r *userRepository) GetByEmail(ctx context.Context, email string) (*User, e
 	return user, nil
 }
 
+// GetByPhone retrieves a user by phone number
+func (r *userRepository) GetByPhone(ctx context.Context, phone string) (*User, error) {
+	user, err := r.ormRepo.FindOne(ctx, bson.M{"phone": phone})
+	if err != nil {
+		if errors.Is(err, orm.ErrDocumentNotFound) {
+			return nil, errors.New("user not found")
+		}
+		r.logger.Error("Failed to get user by phone", map[string]interface{}{
+			"error": err.Error(),
+			"phone": phone,
+		})
+		return nil, err
+	}
+
+	return user, nil
+}
+
 // GetByUsername retrieves a user by username
 func (r *userRepository) GetByUsername(ctx context.Context, username string) (*User, error) {
 	user, err := r.ormRepo.FindOne(ctx, bson.M{"username": username})

internal/user/service.go

@@ -77,6 +77,13 @@ func (s *userService) Register(ctx context.Context, form *CreateUserForm) (*User
 		return nil, errors.New("username already exists")
 	}
 
+	if form.Phone != nil && *form.Phone != "" {
+		existingUser, _ = s.repository.GetByPhone(ctx, *form.Phone)
+		if existingUser != nil {
+			return nil, errors.New("phone number already exists")
+		}
+	}
+
 	// Hash password
 	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(form.Password), bcrypt.DefaultCost)
 	if err != nil {
@@ -110,6 +117,9 @@ func (s *userService) Register(ctx context.Context, form *CreateUserForm) (*User
 	// Save to database
 	err = s.repository.Create(ctx, user)
 	if err != nil {
+		if mapped := mapUserWriteError(err); mapped != err {
+			return nil, mapped
+		}
 		s.logger.Error("Failed to register user", map[string]interface{}{
 			"error":    err.Error(),
 			"email":    form.Email,
@@ -184,7 +194,13 @@ func (s *userService) Update(ctx context.Context, id string, form *UpdateUserFor
 		user.Position = form.Position
 	}
 
-	if form.Phone != nil {
+	if form.Phone != nil && (user.Phone == nil || *form.Phone != *user.Phone) {
+		if *form.Phone != "" {
+			existingUser, _ := s.repository.GetByPhone(ctx, *form.Phone)
+			if existingUser != nil && existingUser.ID.Hex() != id {
+				return nil, errors.New("phone number already exists")
+			}
+		}
 		user.Phone = form.Phone
 	}
 
@@ -195,6 +211,9 @@ func (s *userService) Update(ctx context.Context, id string, form *UpdateUserFor
 	// Update in database
 	err = s.repository.Update(ctx, user)
 	if err != nil {
+		if mapped := mapUserWriteError(err); mapped != err {
+			return nil, mapped
+		}
 		s.logger.Error("Failed to update user", map[string]interface{}{
 			"error":   err.Error(),
 			"user_id": id,
@@ -573,7 +592,13 @@ func (s *userService) UpdateProfile(ctx context.Context, userID string, form *Up
 	if form.Position != nil {
 		user.Position = form.Position
 	}
-	if form.Phone != nil {
+	if form.Phone != nil && (user.Phone == nil || *form.Phone != *user.Phone) {
+		if *form.Phone != "" {
+			existingUser, _ := s.repository.GetByPhone(ctx, *form.Phone)
+			if existingUser != nil && existingUser.ID.Hex() != userID {
+				return errors.New("phone number already exists")
+			}
+		}
 		user.Phone = form.Phone
 	}
 	if form.ProfileImage != nil {
@@ -586,6 +611,9 @@ func (s *userService) UpdateProfile(ctx context.Context, userID string, form *Up
 	// Save to database
 	err = s.repository.Update(ctx, user)
 	if err != nil {
+		if mapped := mapUserWriteError(err); mapped != err {
+			return mapped
+		}
 		s.logger.Error("Failed to update user profile", map[string]interface{}{
 			"error":   err.Error(),
 			"user_id": userID,

pkg/mongo/duplicate.go

@@ -0,0 +1,192 @@
+package mongo
+
+import (
+	"errors"
+	"regexp"
+	"strings"
+
+	mongodriver "go.mongodb.org/mongo-driver/v2/mongo"
+)
+
+var dupKeyFieldNamePattern = regexp.MustCompile(`(?:^|[,{]\s*)([a-zA-Z_][a-zA-Z0-9_]*)\s*:`)
+
+// IsDuplicateKeyError reports whether err is a MongoDB E11000 duplicate key error.
+func IsDuplicateKeyError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	if len(duplicateKeyMessages(err)) > 0 {
+		return true
+	}
+
+	if hasStructuredWriteException(err) {
+		return false
+	}
+
+	msg := strings.ToLower(err.Error())
+	return strings.Contains(msg, "e11000") || strings.Contains(msg, "duplicate key")
+}
+
+// DuplicateKeyMatchesField reports whether a duplicate key error involves the given field
+// by parsing WriteException messages (index name and dup key document keys), not broad
+// substring matching on the full error text.
+func DuplicateKeyMatchesField(err error, field string) bool {
+	if err == nil || field == "" {
+		return false
+	}
+
+	field = strings.ToLower(field)
+	msgs := duplicateKeyMessages(err)
+	if len(msgs) == 0 {
+		if hasStructuredWriteException(err) {
+			return false
+		}
+		if !IsDuplicateKeyError(err) {
+			return false
+		}
+		msgs = []string{err.Error()}
+	}
+	for _, msg := range msgs {
+		if duplicateKeyMessageMatchesField(msg, field) {
+			return true
+		}
+	}
+	return false
+}
+
+func duplicateKeyMessages(err error) []string {
+	var msgs []string
+
+	var writeException mongodriver.WriteException
+	if errors.As(err, &writeException) {
+		for _, writeErr := range writeException.WriteErrors {
+			if writeErr.Code == 11000 {
+				msgs = append(msgs, writeErr.Message)
+			}
+		}
+	}
+
+	var bulkWriteException mongodriver.BulkWriteException
+	if errors.As(err, &bulkWriteException) {
+		for _, writeErr := range bulkWriteException.WriteErrors {
+			if writeErr.Code == 11000 {
+				msgs = append(msgs, writeErr.Message)
+			}
+		}
+	}
+
+	return msgs
+}
+
+func hasStructuredWriteException(err error) bool {
+	var writeException mongodriver.WriteException
+	if errors.As(err, &writeException) {
+		return true
+	}
+
+	var bulkWriteException mongodriver.BulkWriteException
+	return errors.As(err, &bulkWriteException)
+}
+
+func duplicateKeyMessageMatchesField(message, field string) bool {
+	message = strings.ToLower(message)
+
+	if indexName := extractDuplicateIndexName(message); indexName != "" {
+		if indexNameMatchesField(indexName, field) {
+			return true
+		}
+	}
+
+	for _, key := range extractDuplicateKeyFields(message) {
+		if key == field {
+			return true
+		}
+	}
+
+	return false
+}
+
+func extractDuplicateIndexName(message string) string {
+	const prefix = "index: "
+	start := strings.Index(message, prefix)
+	if start < 0 {
+		return ""
+	}
+
+	rest := strings.TrimSpace(message[start+len(prefix):])
+	if rest == "" {
+		return ""
+	}
+
+	end := strings.IndexByte(rest, ' ')
+	if end >= 0 {
+		return rest[:end]
+	}
+
+	return rest
+}
+
+func indexNameMatchesField(indexName, field string) bool {
+	switch indexName {
+	case field, field + "_idx", field + "_1":
+		return true
+	default:
+		return false
+	}
+}
+
+func extractDuplicateKeyFields(message string) []string {
+	const prefix = "dup key:"
+	start := strings.Index(message, prefix)
+	if start < 0 {
+		return nil
+	}
+
+	document := strings.TrimSpace(message[start+len(prefix):])
+	if !strings.HasPrefix(document, "{") {
+		return nil
+	}
+
+	depth := 0
+	end := -1
+	for i, char := range document {
+		switch char {
+		case '{':
+			depth++
+		case '}':
+			depth--
+			if depth == 0 {
+				end = i
+			}
+		}
+		if end >= 0 {
+			break
+		}
+	}
+	if end <= 0 {
+		return nil
+	}
+
+	inner := strings.TrimSpace(document[1:end])
+	matches := dupKeyFieldNamePattern.FindAllStringSubmatch(inner, -1)
+	if len(matches) == 0 {
+		return nil
+	}
+
+	fields := make([]string, 0, len(matches))
+	seen := make(map[string]struct{}, len(matches))
+	for _, match := range matches {
+		if len(match) < 2 {
+			continue
+		}
+		key := strings.ToLower(match[1])
+		if _, ok := seen[key]; ok {
+			continue
+		}
+		seen[key] = struct{}{}
+		fields = append(fields, key)
+	}
+
+	return fields
+}

pkg/mongo/duplicate_test.go

@@ -0,0 +1,303 @@
+package mongo
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	mongodriver "go.mongodb.org/mongo-driver/v2/mongo"
+)
+
+func TestIsDuplicateKeyError(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name string
+		err  error
+		want bool
+	}{
+		{
+			name: "nil error",
+			err:  nil,
+			want: false,
+		},
+		{
+			name: "unrelated error",
+			err:  errors.New("connection refused"),
+			want: false,
+		},
+		{
+			name: "write exception duplicate key",
+			err: writeExceptionWithMessage(
+				11000,
+				`E11000 duplicate key error collection: tm.users index: phone_idx dup key: { phone: "+1234567890" }`,
+			),
+			want: true,
+		},
+		{
+			name: "write exception non duplicate code",
+			err: writeExceptionWithMessage(
+				121,
+				`Document failed validation`,
+			),
+			want: false,
+		},
+		{
+			name: "wrapped write exception duplicate key",
+			err: fmt.Errorf(
+				"failed to create user: %w",
+				writeExceptionWithMessage(
+					11000,
+					`E11000 duplicate key error collection: tm.users index: username_idx dup key: { username: "admin" }`,
+				),
+			),
+			want: true,
+		},
+		{
+			name: "bulk write exception duplicate key",
+			err: bulkWriteExceptionWithMessage(
+				11000,
+				`E11000 duplicate key error collection: tm.customers index: phone_idx dup key: { phone: "+1234567890" }`,
+			),
+			want: true,
+		},
+		{
+			name: "string fallback duplicate key",
+			err:  errors.New(`write exception: write errors: [E11000 duplicate key error collection: tm.users index: phone_idx dup key: { phone: "+1234567890" }] `),
+			want: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			if got := IsDuplicateKeyError(tt.err); got != tt.want {
+				t.Fatalf("IsDuplicateKeyError() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestDuplicateKeyMatchesField(t *testing.T) {
+	t.Parallel()
+
+	const phoneMsg = `E11000 duplicate key error collection: tm.users index: phone_idx dup key: { phone: "+1234567890" }`
+	const usernameMsg = `E11000 duplicate key error collection: tm.users index: username_idx dup key: { username: "admin" }`
+	const emailMsg = `E11000 duplicate key error collection: tm.customers index: email_1 dup key: { email: "user@example.com" }`
+	const phoneValueContainsNameMsg = `E11000 duplicate key error collection: tm.users index: phone_idx dup key: { phone: "username-like-value" }`
+
+	tests := []struct {
+		name  string
+		err   error
+		field string
+		want  bool
+	}{
+		{
+			name:  "nil error",
+			err:   nil,
+			field: "phone",
+			want:  false,
+		},
+		{
+			name:  "empty field",
+			err:   writeExceptionWithMessage(11000, phoneMsg),
+			field: "",
+			want:  false,
+		},
+		{
+			name:  "phone duplicate matches phone field",
+			err:   writeExceptionWithMessage(11000, phoneMsg),
+			field: "phone",
+			want:  true,
+		},
+		{
+			name:  "phone duplicate does not match email field",
+			err:   writeExceptionWithMessage(11000, phoneMsg),
+			field: "email",
+			want:  false,
+		},
+		{
+			name:  "username duplicate matches username field",
+			err:   writeExceptionWithMessage(11000, usernameMsg),
+			field: "username",
+			want:  true,
+		},
+		{
+			name:  "username duplicate does not match name substring",
+			err:   writeExceptionWithMessage(11000, usernameMsg),
+			field: "name",
+			want:  false,
+		},
+		{
+			name:  "email duplicate matches email field via default index suffix",
+			err:   writeExceptionWithMessage(11000, emailMsg),
+			field: "email",
+			want:  true,
+		},
+		{
+			name:  "dup key value substring does not match unrelated field",
+			err:   writeExceptionWithMessage(11000, phoneValueContainsNameMsg),
+			field: "name",
+			want:  false,
+		},
+		{
+			name:  "wrapped duplicate key matches field",
+			err: fmt.Errorf(
+				"failed to register customer: %w",
+				writeExceptionWithMessage(11000, phoneMsg),
+			),
+			field: "phone",
+			want:  true,
+		},
+		{
+			name:  "non duplicate write error does not match",
+			err:   writeExceptionWithMessage(121, phoneMsg),
+			field: "phone",
+			want:  false,
+		},
+		{
+			name:  "unrelated error does not match",
+			err:   errors.New("timeout"),
+			field: "phone",
+			want:  false,
+		},
+		{
+			name:  "string fallback duplicate key matches field",
+			err:   errors.New(`write exception: write errors: [E11000 duplicate key error collection: tm.users index: phone_idx dup key: { phone: "+1234567890" }] `),
+			field: "phone",
+			want:  true,
+		},
+		{
+			name:  "string fallback duplicate key does not match unrelated field",
+			err:   errors.New(`write exception: write errors: [E11000 duplicate key error collection: tm.users index: username_idx dup key: { username: "admin" }] `),
+			field: "name",
+			want:  false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			if got := DuplicateKeyMatchesField(tt.err, tt.field); got != tt.want {
+				t.Fatalf("DuplicateKeyMatchesField(%q) = %v, want %v", tt.field, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestExtractDuplicateIndexName(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name    string
+		message string
+		want    string
+	}{
+		{
+			name:    "phone index",
+			message: `E11000 duplicate key error collection: tm.users index: phone_idx dup key: { phone: "+1234567890" }`,
+			want:    "phone_idx",
+		},
+		{
+			name:    "missing index segment",
+			message: `E11000 duplicate key error collection: tm.users dup key: { phone: "+1234567890" }`,
+			want:    "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			if got := extractDuplicateIndexName(tt.message); got != tt.want {
+				t.Fatalf("extractDuplicateIndexName() = %q, want %q", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestExtractDuplicateKeyFields(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name    string
+		message string
+		want    []string
+	}{
+		{
+			name:    "single field",
+			message: `index: phone_idx dup key: { phone: "+1234567890" }`,
+			want:    []string{"phone"},
+		},
+		{
+			name:    "compound dup key",
+			message: `index: user_company_idx dup key: { user_id: ObjectId('507f1f77bcf86cd799439011'), company_id: ObjectId('507f1f77bcf86cd799439012') }`,
+			want:    []string{"user_id", "company_id"},
+		},
+		{
+			name:    "value containing colon does not add false field",
+			message: `index: phone_idx dup key: { phone: "office:123" }`,
+			want:    []string{"phone"},
+		},
+		{
+			name:    "missing dup key segment",
+			message: `index: phone_idx`,
+			want:    nil,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			got := extractDuplicateKeyFields(tt.message)
+			if len(got) != len(tt.want) {
+				t.Fatalf("extractDuplicateKeyFields() = %v, want %v", got, tt.want)
+			}
+			for i := range got {
+				if got[i] != tt.want[i] {
+					t.Fatalf("extractDuplicateKeyFields() = %v, want %v", got, tt.want)
+				}
+			}
+		})
+	}
+}
+
+func TestIndexNameMatchesField(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		indexName string
+		field     string
+		want      bool
+	}{
+		{indexName: "phone_idx", field: "phone", want: true},
+		{indexName: "phone_1", field: "phone", want: true},
+		{indexName: "phone", field: "phone", want: true},
+		{indexName: "username_idx", field: "name", want: false},
+		{indexName: "email_idx", field: "mail", want: false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.indexName+"_"+tt.field, func(t *testing.T) {
+			t.Parallel()
+			if got := indexNameMatchesField(tt.indexName, tt.field); got != tt.want {
+				t.Fatalf("indexNameMatchesField(%q, %q) = %v, want %v", tt.indexName, tt.field, got, tt.want)
+			}
+		})
+	}
+}
+
+func writeExceptionWithMessage(code int, message string) error {
+	return mongodriver.WriteException{
+		WriteErrors: []mongodriver.WriteError{
+			{Code: code, Message: message},
+		},
+	}
+}
+
+func bulkWriteExceptionWithMessage(code int, message string) error {
+	return mongodriver.BulkWriteException{
+		WriteErrors: []mongodriver.BulkWriteError{
+			{WriteError: mongodriver.WriteError{Code: code, Message: message}},
+		},
+	}
+}