refac: several unverified users can exist at once: an empty reset or verification code is stored as no value so it doesn't break the unique constraint, and deleting a user removes the row so the same username and email can register again

features/unverified_users_and_reregistration.feature

@@ -0,0 +1,70 @@
+Feature: Several unverified users can coexist, and deleting a user frees its username and email
+
+  As the maintainer of RenewCMS
+  I want an absent password reset code or verification code stored as no value instead of an empty
+    string, and a deleted user's row actually removed
+  So that several unverified users can register one after another without colliding on the unique
+    reset-code column, and so that deleting a user lets the same username and email register again
+
+  Background:
+    Given internal/infrastructure/persistence/models.User stores PasswordResetCode and VerificationCode
+      as nullable, unique columns, so a domain value of "" is persisted as no value (SQL NULL), and SQL
+      NULL is exempt from the unique constraint
+    And internal/infrastructure/persistence/mappers.UserToModel maps a domain "" for PasswordResetCode or
+      VerificationCode to no value, and UserToDomain maps no value back to ""
+    And internal/infrastructure/persistence/models.User no longer embeds gorm.Model, so
+      UserRepository.Delete removes the row instead of leaving a soft-deleted row that still occupies the
+      unique username and email
+    And POST /v1/auth/register is public, and CreateUser stores a new user with is_verified false and
+      PasswordResetCode "" as soon as the request is valid
+    And Register only answers 403 once at least one existing user is verified (SomeUsersVerified), never
+      because the user table already has rows
+    And DeleteUser has no handler mounted in api/router.go today, so deletion in these scenarios is
+      exercised through UserRepository.Delete / DeleteUserUseCase.DeleteUser directly, not through an
+      HTTP route
+
+  Scenario: Two unverified users can register one after another without a reset-code collision
+    Given the user repository is empty
+    When the client sends POST /v1/auth/register with username "alice", password "hunter2example12",
+      email "alice@example.com"
+    Then the response status is 200
+    And a jwt cookie is set
+    When the client sends POST /v1/auth/register with username "bob", password "hunter2example12",
+      email "bob@example.com"
+    Then the response status is 200
+    And a jwt cookie is set
+    And the user repository contains both "alice" and "bob", each with is_verified false and an empty
+      password reset code
+
+  Scenario: Creating two users with no active reset code does not violate the unique constraint
+    Given a repository backed by an in-memory SQLite database with models.User migrated
+    When Create is called with username "alice", email "alice@example.com", password_reset_code "" and
+      verification_code "code-alice"
+    And Create is called with username "bob", email "bob@example.com", password_reset_code "" and
+      verification_code "code-bob"
+    Then both calls succeed
+    And GetByUsername "alice" and GetByUsername "bob" each return password_reset_code ""
+
+  Scenario: The unique constraint still rejects two users sharing the same active reset code
+    Given a repository backed by an in-memory SQLite database containing a user "alice" with
+      password_reset_code "shared-code"
+    When Create is called with username "bob", email "bob@example.com" and password_reset_code
+      "shared-code"
+    Then the Create call returns an error
+    And GetByUsername "bob" still returns user.ErrUserNotFound
+
+  Scenario: Deleting a user removes the row so the same username and email can register again
+    Given a repository backed by an in-memory SQLite database containing a user with id 1, username
+      "alice" and email "alice@example.com"
+    When Delete is called with id 1
+    And Create is called with username "alice", email "alice@example.com" and a new password
+    Then the Create call succeeds
+    And the newly created user's id is different from 1
+    And Get with id 1 returns user.ErrUserNotFound
+
+  Scenario: Registering the same username while the first account still exists is still rejected
+    Given a repository backed by an in-memory SQLite database containing a user with username "alice"
+      and email "alice@example.com"
+    When Create is called with username "alice", email "someone-else@example.com" and a new password
+    Then the Create call returns an error
+    And the user repository still contains exactly one user with username "alice"

features/unverified_users_and_reregistration.qa.md

@@ -0,0 +1,50 @@
+# QA procedure: unverified_users_and_reregistration
+
+Package: `test` (black-box), extending `test/user_test.go` (mockUserRepo) and reusing the
+`openInMemoryDb(t)` helper from `test/not_found_errors_test.go`.
+
+## Setup shared by every case
+1. Call `validator.InitValidator()` once.
+2. Repository-level checks use `openInMemoryDb(t)`, `db.AutoMigrate(&models.User{})`, and a real
+   `persistence.NewUserRepository(db)`.
+3. HTTP-level checks use `mockUserRepo` (from `test/user_test.go`) wired into
+   `useCases.NewCreateUserUseCase(repo, &hashing.BcryptHasher{})`,
+   `useCases.NewListUsersUseCase(repo)`, `useCases.NewGetUserUseCase(repo)`,
+   `useCases.NewAuthenticateUserUseCase(repo, ...)`, and `auth.NewHandler(...)` with a test
+   `jwtauth.New("HS256", []byte("test-secret"), nil)`. Mount `POST /v1/auth/register` and
+   `POST /v1/auth/login` unprotected on a fresh `chi.NewRouter()`, mirroring `api/router.go`. No live
+   server.
+
+## Repository-level checks (real persistence repository, in-memory SQLite, no HTTP)
+4. On an empty repository, `Create` a user "alice"/"alice@example.com" with `PasswordResetCode: ""` and
+   `VerificationCode: "code-alice"` → assert `err == nil`. `Create` a second user "bob"/"bob@example.com"
+   with `PasswordResetCode: ""` and `VerificationCode: "code-bob"` → assert `err == nil` (regression: before
+   the fix this fails with a SQLite `UNIQUE constraint failed: users.password_reset_code` error). Then
+   `GetByUsername("alice")` and `GetByUsername("bob")` → assert `PasswordResetCode == ""` for both.
+5. `Create` a user "alice" with `PasswordResetCode: "shared-code"`. `Create` a user "bob" with the same
+   `PasswordResetCode: "shared-code"` → assert `err != nil` (the unique constraint still applies to an
+   actual shared value). Assert `GetByUsername("bob")` returns `user.ErrUserNotFound` (the row was never
+   created).
+6. `Create` a user "alice"/"alice@example.com", capture its id. `Delete(id)` → assert `err == nil`.
+   `Create` a new user with the same username "alice" and email "alice@example.com" (a different
+   password and verification code) → assert `err == nil` (regression: before the fix this fails with a
+   SQLite `UNIQUE constraint failed: users.username` error because the row was only soft-deleted). Assert
+   the new user's id differs from the deleted one. Assert `Get(deletedId)` returns `user.ErrUserNotFound`.
+7. `Create` a user "alice"/"alice@example.com" and do **not** delete it. `Create` a second user with
+   username "alice" and a different email → assert `err != nil` (unchanged: still rejected while the row
+   is live).
+
+## HTTP checks (fakes, per the shared setup above)
+8. `POST /v1/auth/register` with `{"username":"alice","password":"hunter2example12","email":"alice@example.com"}`
+   against an empty `mockUserRepo` → assert status `200`, a `Set-Cookie: jwt=...` header present, body
+   decodes to `{"message":"User registered! HTTPonly jwt cookie created"}`.
+9. `POST /v1/auth/register` again with `{"username":"bob","password":"hunter2example12","email":"bob@example.com"}`
+   (repo now holds unverified "alice") → assert status `200` and a `Set-Cookie: jwt=...` header present
+   (register stays allowed because no user is verified yet).
+10. Assert `mockUserRepo.users` holds two entries, both `IsVerified == false` and both
+    `PasswordResetCode == ""`.
+
+## Manual verification (not exercised by the Go test)
+- None. `DeleteUser` has no HTTP route mounted today, so there is no SPA-visible delete-and-re-register
+  flow to check by hand, and `CreateUser` does not call the mailer, so there is no SMTP involvement in
+  this slice.

internal/infrastructure/persistence/mappers/userMapper.go

@@ -5,15 +5,29 @@ import (
 	"RenewCMS/internal/infrastructure/persistence/models"
 )
 
+func nullableStringToDomain(value *string) string {
+	if value == nil {
+		return ""
+	}
+	return *value
+}
+
+func DomainToNullableString(value string) *string {
+	if value == "" {
+		return nil
+	}
+	return &value
+}
+
 func UserToDomain(m models.User) user.User {
 	return user.User{
 		ID:                     m.ID,
 		Username:               m.Username,
 		Password:               m.Password,
-		PasswordResetCode:      m.PasswordResetCode,
+		PasswordResetCode:      nullableStringToDomain(m.PasswordResetCode),
 		Email:                  m.Email,
 		IsVerified:             m.IsVerified,
-		VerificationCode:       m.VerificationCode,
+		VerificationCode:       nullableStringToDomain(m.VerificationCode),
 		VerificationExpiration: m.VerificationExpiration,
 		CreatedAt:              m.CreatedAt,
 		UpdatedAt:              m.UpdatedAt,
@@ -24,10 +38,10 @@ func UserToModel(a user.User) models.User {
 	return models.User{
 		Username:               a.Username,
 		Password:               a.Password,
-		PasswordResetCode:      a.PasswordResetCode,
+		PasswordResetCode:      DomainToNullableString(a.PasswordResetCode),
 		Email:                  a.Email,
 		IsVerified:             a.IsVerified,
-		VerificationCode:       a.VerificationCode,
+		VerificationCode:       DomainToNullableString(a.VerificationCode),
 		VerificationExpiration: a.VerificationExpiration,
 		CreatedAt:              a.CreatedAt,
 		UpdatedAt:              a.UpdatedAt,

internal/infrastructure/persistence/models/userModel.go

@@ -2,19 +2,16 @@ package models
 
 import (
 	"time"
-
-	"gorm.io/gorm"
 )
 
 type User struct {
-	gorm.Model
-	ID                     uint32 `gorm:"primaryKey;autoIncrement"`
-	Username               string `gorm:"unique;not null"`
-	Password               string `gorm:"not null"`
-	PasswordResetCode      string `gorm:"unique"`
-	Email                  string `gorm:"unique;not null"`
-	IsVerified             bool   `gorm:"default=false;not null"`
-	VerificationCode       string `gorm:"unique"`
+	ID                     uint32  `gorm:"primaryKey;autoIncrement"`
+	Username               string  `gorm:"unique;not null"`
+	Password               string  `gorm:"not null"`
+	PasswordResetCode      *string `gorm:"unique"`
+	Email                  string  `gorm:"unique;not null"`
+	IsVerified             bool    `gorm:"default=false;not null"`
+	VerificationCode       *string `gorm:"unique"`
 	VerificationExpiration time.Time
 	CreatedAt              time.Time `gorm:"autoCreateTime"`
 	UpdatedAt              time.Time `gorm:"autoUpdateTime"`

internal/infrastructure/persistence/repositories/userRepository.go

@@ -30,8 +30,9 @@ func (u *UserRepository) Create(user domainUser.User) (domainUser.User, error) {
 	creationResult := u.db.Create(&entity.User{
 		Username:               user.Username,
 		Password:               user.Password,
+		PasswordResetCode:      mappers.DomainToNullableString(user.PasswordResetCode),
 		Email:                  user.Email,
-		VerificationCode:       user.VerificationCode,
+		VerificationCode:       mappers.DomainToNullableString(user.VerificationCode),
 		VerificationExpiration: user.VerificationExpiration,
 	})
 	if creationResult.Error != nil {
@@ -121,7 +122,7 @@ func (u *UserRepository) UpdatePasswordResetCode(userId uint32, code string) (do
 		return domainUser.User{}, mapNotFoundErr(err, domainUser.ErrUserNotFound)
 	}
 
-	localUser.PasswordResetCode = code
+	localUser.PasswordResetCode = mappers.DomainToNullableString(code)
 	err = u.db.Save(&localUser).Error
 	if err != nil {
 		return domainUser.User{}, err

test/unverified_users_and_reregistration_test.go

@@ -0,0 +1,229 @@
+package test
+
+import (
+	"RenewCMS/api/handlers/auth"
+	validator "RenewCMS/api/pkg/validator"
+	domainUser "RenewCMS/internal/domain/user"
+	"RenewCMS/internal/infrastructure/hashing"
+	"RenewCMS/internal/infrastructure/persistence/models"
+	persistence "RenewCMS/internal/infrastructure/persistence/repositories"
+	"RenewCMS/internal/infrastructure/useCases"
+	"bytes"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/jwtauth/v5"
+)
+
+func newMigratedUserRepository(t *testing.T) *persistence.UserRepository {
+	t.Helper()
+	db := openInMemoryDb(t)
+	if err := db.AutoMigrate(&models.User{}); err != nil {
+		t.Fatalf("failed to migrate: %v", err)
+	}
+	return persistence.NewUserRepository(db)
+}
+
+func TestUnverifiedUsersAndReregistrationRepository(t *testing.T) {
+	t.Run("Creating two users with no active reset code does not violate the unique constraint", func(t *testing.T) {
+		repo := newMigratedUserRepository(t)
+
+		if _, err := repo.Create(domainUser.User{Username: "alice", Email: "alice@example.com", Password: "hunter2example12", PasswordResetCode: "", VerificationCode: "code-alice"}); err != nil {
+			t.Fatalf("expected alice creation to succeed, got %v", err)
+		}
+		if _, err := repo.Create(domainUser.User{Username: "bob", Email: "bob@example.com", Password: "hunter2example12", PasswordResetCode: "", VerificationCode: "code-bob"}); err != nil {
+			t.Fatalf("expected bob creation to succeed, got %v", err)
+		}
+
+		alice, err := repo.GetByUsername("alice")
+		if err != nil {
+			t.Fatalf("failed to get alice: %v", err)
+		}
+		if alice.PasswordResetCode != "" {
+			t.Errorf("expected empty password reset code for alice, got %q", alice.PasswordResetCode)
+		}
+
+		bob, err := repo.GetByUsername("bob")
+		if err != nil {
+			t.Fatalf("failed to get bob: %v", err)
+		}
+		if bob.PasswordResetCode != "" {
+			t.Errorf("expected empty password reset code for bob, got %q", bob.PasswordResetCode)
+		}
+	})
+
+	t.Run("The unique constraint still rejects two users sharing the same active reset code", func(t *testing.T) {
+		repo := newMigratedUserRepository(t)
+
+		if _, err := repo.Create(domainUser.User{Username: "alice", Email: "alice@example.com", Password: "hunter2example12", PasswordResetCode: "shared-code", VerificationCode: "code-alice"}); err != nil {
+			t.Fatalf("expected alice creation to succeed, got %v", err)
+		}
+
+		_, err := repo.Create(domainUser.User{Username: "bob", Email: "bob@example.com", Password: "hunter2example12", PasswordResetCode: "shared-code", VerificationCode: "code-bob"})
+		if err == nil {
+			t.Fatal("expected Create for bob to fail because of the shared reset code")
+		}
+
+		_, err = repo.GetByUsername("bob")
+		if !errors.Is(err, domainUser.ErrUserNotFound) {
+			t.Errorf("expected user.ErrUserNotFound, got %v", err)
+		}
+	})
+
+	t.Run("Deleting a user removes the row so the same username and email can register again", func(t *testing.T) {
+		repo := newMigratedUserRepository(t)
+
+		created, err := repo.Create(domainUser.User{Username: "alice", Email: "alice@example.com", Password: "hunter2example12", VerificationCode: "code-alice"})
+		if err != nil {
+			t.Fatalf("failed to seed alice: %v", err)
+		}
+
+		if err := repo.Delete(created.ID); err != nil {
+			t.Fatalf("expected delete to succeed, got %v", err)
+		}
+
+		recreated, err := repo.Create(domainUser.User{Username: "alice", Email: "alice@example.com", Password: "differentpassword12", VerificationCode: "code-alice-2"})
+		if err != nil {
+			t.Fatalf("expected alice to be re-registrable after deletion, got %v", err)
+		}
+		if recreated.ID == created.ID {
+			t.Errorf("expected the recreated user to have a different id than %d", created.ID)
+		}
+
+		_, err = repo.Get(created.ID)
+		if !errors.Is(err, domainUser.ErrUserNotFound) {
+			t.Errorf("expected user.ErrUserNotFound for the deleted id, got %v", err)
+		}
+	})
+
+	t.Run("Registering the same username while the first account still exists is still rejected", func(t *testing.T) {
+		repo := newMigratedUserRepository(t)
+
+		if _, err := repo.Create(domainUser.User{Username: "alice", Email: "alice@example.com", Password: "hunter2example12", VerificationCode: "code-alice"}); err != nil {
+			t.Fatalf("failed to seed alice: %v", err)
+		}
+
+		_, err := repo.Create(domainUser.User{Username: "alice", Email: "someone-else@example.com", Password: "anotherpassword12", VerificationCode: "code-alice-2"})
+		if err == nil {
+			t.Fatal("expected Create to fail because the username is still in use")
+		}
+
+		users := repo.GetAll()
+		count := 0
+		for _, u := range users {
+			if u.Username == "alice" {
+				count++
+			}
+		}
+		if count != 1 {
+			t.Errorf("expected exactly one user with username alice, got %d", count)
+		}
+	})
+
+	t.Run("Updating a user's reset code to one already active for another user is rejected", func(t *testing.T) {
+		repo := newMigratedUserRepository(t)
+
+		if _, err := repo.Create(domainUser.User{Username: "alice", Email: "alice@example.com", Password: "hunter2example12", PasswordResetCode: "alice-code", VerificationCode: "code-alice"}); err != nil {
+			t.Fatalf("expected alice creation to succeed, got %v", err)
+		}
+		bob, err := repo.Create(domainUser.User{Username: "bob", Email: "bob@example.com", Password: "hunter2example12", VerificationCode: "code-bob"})
+		if err != nil {
+			t.Fatalf("expected bob creation to succeed, got %v", err)
+		}
+
+		_, err = repo.UpdatePasswordResetCode(bob.ID, "alice-code")
+		if err == nil {
+			t.Fatal("expected UpdatePasswordResetCode for bob to fail because the code is already active for alice")
+		}
+
+		reloadedBob, err := repo.Get(bob.ID)
+		if err != nil {
+			t.Fatalf("failed to reload bob: %v", err)
+		}
+		if reloadedBob.PasswordResetCode != "" {
+			t.Errorf("expected bob's reset code to remain unset, got %q", reloadedBob.PasswordResetCode)
+		}
+	})
+}
+
+func newUnverifiedRegistrationRouter(userRepo *mockUserRepo, token *jwtauth.JWTAuth) *chi.Mux {
+	hasher := hashing.NewBcryptHasher()
+	authHandler := auth.NewHandler(
+		token,
+		useCases.NewGetUserUseCase(userRepo),
+		useCases.NewListUsersUseCase(userRepo),
+		useCases.NewCreateUserUseCase(userRepo, hasher),
+		useCases.NewAuthenticateUserUseCase(userRepo, hasher),
+		true,
+	)
+
+	r := chi.NewRouter()
+	r.Route("/v1", func(r chi.Router) {
+		r.Route("/auth", func(r chi.Router) {
+			r.Post("/register", authHandler.Register)
+		})
+	})
+	return r
+}
+
+func registerViaHttp(t *testing.T, router *chi.Mux, username, password, email string) *httptest.ResponseRecorder {
+	t.Helper()
+	body, err := json.Marshal(map[string]string{"username": username, "password": password, "email": email})
+	if err != nil {
+		t.Fatalf("failed to marshal body: %v", err)
+	}
+	req := httptest.NewRequest(http.MethodPost, "/v1/auth/register", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	return rec
+}
+
+func TestUnverifiedUsersAndReregistrationHttp(t *testing.T) {
+	validator.InitValidator()
+	token := jwtauth.New("HS256", []byte("test-secret"), nil)
+
+	t.Run("Two unverified users can register one after another without a reset-code collision", func(t *testing.T) {
+		repo := newMockUserRepo()
+		router := newUnverifiedRegistrationRouter(repo, token)
+
+		aliceRec := registerViaHttp(t, router, "alice", "hunter2example12", "alice@example.com")
+		if aliceRec.Code != http.StatusOK {
+			t.Fatalf("expected status 200 for alice, got %d: %s", aliceRec.Code, aliceRec.Body.String())
+		}
+		if aliceRec.Header().Get("Set-Cookie") == "" {
+			t.Errorf("expected a jwt cookie to be set for alice")
+		}
+		var aliceBody map[string]string
+		if err := json.Unmarshal(aliceRec.Body.Bytes(), &aliceBody); err != nil {
+			t.Fatalf("failed to decode alice response body: %v", err)
+		}
+		if aliceBody["message"] != "User registered! HTTPonly jwt cookie created" {
+			t.Errorf("unexpected response body for alice: %v", aliceBody)
+		}
+
+		bobRec := registerViaHttp(t, router, "bob", "hunter2example12", "bob@example.com")
+		if bobRec.Code != http.StatusOK {
+			t.Fatalf("expected status 200 for bob, got %d: %s", bobRec.Code, bobRec.Body.String())
+		}
+		if bobRec.Header().Get("Set-Cookie") == "" {
+			t.Errorf("expected a jwt cookie to be set for bob")
+		}
+
+		if len(repo.users) != 2 {
+			t.Fatalf("expected 2 users in the repository, got %d", len(repo.users))
+		}
+		for _, u := range repo.users {
+			if u.IsVerified {
+				t.Errorf("expected user %q to be unverified", u.Username)
+			}
+			if u.PasswordResetCode != "" {
+				t.Errorf("expected user %q to have an empty password reset code, got %q", u.Username, u.PasswordResetCode)
+			}
+		}
+	})
+}