feat(persistence): add UserRepository.UpdateImage

Adds the interface method, real repository implementation, and mock
together so the build stays green. UpdateImage sets updated_at
explicitly in the same UPDATE statement, since AvatarTag's ETag
derives from uploaded_image + updated_at.

model/user.go

@@ -73,6 +73,8 @@ type UserRepository interface {
 	Get(id string) (*User, error)
 	GetAll(options ...QueryOptions) (Users, error)
 	Put(*User) error
+	// UpdateImage is the only writer of uploaded_image. See the field comment on User.
+	UpdateImage(id string, filename string) error
 	UpdateLastLoginAt(id string) error
 	UpdateLastAccessAt(id string) error
 	FindFirstAdmin() (*User, error)

persistence/user_repository.go

@@ -189,6 +189,21 @@ func (r *userRepository) Put(u *model.User) error {
 	return nil
 }
 
+func (r *userRepository) UpdateImage(id string, filename string) error {
+	upd := Update(r.tableName).
+		Set("uploaded_image", filename).
+		Set("updated_at", time.Now()).
+		Where(Eq{"id": id})
+	count, err := r.executeSQL(upd)
+	if err != nil {
+		return err
+	}
+	if count == 0 {
+		return model.ErrNotFound
+	}
+	return nil
+}
+
 func (r *userRepository) FindFirstAdmin() (*model.User, error) {
 	sel := r.selectUserWithLibraries(model.QueryOptions{Sort: "updated_at", Max: 1}).Where(Eq{"user.is_admin": true})
 	var usr dbUser

persistence/user_repository_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"slices"
 	"sync"
+	"time"
 
 	"github.com/Masterminds/squirrel"
 	"github.com/deluan/rest"
@@ -94,6 +95,45 @@ var _ = Describe("UserRepository", func() {
 		})
 	})
 
+	Describe("UpdateImage", func() {
+		It("stores the filename and bumps updated_at", func() {
+			before := time.Now().Add(-time.Hour)
+			Expect(repo.UpdateImage(adminUser.ID, "u1_admin.png")).To(Succeed())
+
+			usr, err := repo.Get(adminUser.ID)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(usr.UploadedImage).To(Equal("u1_admin.png"))
+			Expect(usr.UpdatedAt).To(BeTemporally(">", before))
+		})
+
+		It("is not erased by a later full-row Put", func() {
+			Expect(repo.UpdateImage(adminUser.ID, "u1_admin.png")).To(Succeed())
+
+			usr, err := repo.Get(adminUser.ID)
+			Expect(err).ToNot(HaveOccurred())
+			usr.Name = "Renamed"
+			Expect(repo.Put(usr)).To(Succeed())
+
+			usr, err = repo.Get(adminUser.ID)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(usr.UploadedImage).To(Equal("u1_admin.png"))
+		})
+
+		It("clears the filename when given an empty string", func() {
+			Expect(repo.UpdateImage(adminUser.ID, "u1_admin.png")).To(Succeed())
+			Expect(repo.UpdateImage(adminUser.ID, "")).To(Succeed())
+
+			usr, err := repo.Get(adminUser.ID)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(usr.UploadedImage).To(BeEmpty())
+		})
+
+		It("returns ErrNotFound for an unknown id", func() {
+			err := repo.UpdateImage("no-such-user", "x.png")
+			Expect(err).To(MatchError(model.ErrNotFound))
+		})
+	})
+
 	Describe("validatePasswordChange", func() {
 		var loggedUser *model.User
 

tests/mock_user_repo.go

@@ -92,6 +92,20 @@ func (u *MockedUserRepo) GetAll(options ...model.QueryOptions) (model.Users, err
 	return users, nil
 }
 
+func (u *MockedUserRepo) UpdateImage(id string, filename string) error {
+	if u.Error != nil {
+		return u.Error
+	}
+	for _, usr := range u.Data {
+		if usr.ID == id {
+			usr.UploadedImage = filename
+			usr.UpdatedAt = time.Now()
+			return nil
+		}
+	}
+	return model.ErrNotFound
+}
+
 func (u *MockedUserRepo) UpdateLastLoginAt(id string) error {
 	for _, usr := range u.Data {
 		if usr.ID == id {