Return 404 errors for missing resources.

Update login and register forms to return the right errors when the user
info can't be found.

internal/data/user/user.go

@@ -129,11 +129,38 @@ func create(username, email, password string) (*User, error) {
 
 type Error struct {
 	invalid map[string]string
+
+	// missingEmail gets set when the user tries to log in without a real email.
+	// This causes the frontend to respond with an "Invalid email or password" message.
+	// Might want to change this implementation later, just needed something quick.
+	missingEmail string
+	missingHash  string
 }
 
-func (err Error) Invalid() map[string]string { return err.invalid }
+func (err Error) Invalid() map[string]string {
+	switch {
+	case err.missingHash != "":
+		return map[string]string{
+			"confirmation_hash": "Confirmation token unknown or already used.",
+		}
+	case err.missingEmail != "":
+		return map[string]string{
+			"email":    "Invalid email or password.",
+			"password": "Invalid email or password.",
+		}
+	default:
+		return err.invalid
+	}
+}
 
 func (err Error) Error() string {
+	switch {
+	case err.missingEmail != "":
+		return fmt.Sprintf("user with email %q not found", err.missingEmail)
+	case err.missingHash != "":
+		return fmt.Sprintf("user confirmation hash %q", err.missingHash)
+	}
+
 	switch len(err.invalid) {
 	case 0:
 		return "user validation failed"

internal/data/user/user_postgres.go

@@ -56,7 +56,7 @@ func (d *Postgres) ConfirmUser(ctx context.Context, confirmation string) error {
 	if tag, err := d.db.Exec(ctx, q, confirmation); err != nil {
 		return fmt.Errorf("set postgres confirmation_hash to NULL: %w", err)
 	} else if tag.RowsAffected() == 0 {
-		return errors.New("unknown confirmation_hash in postgres")
+		return Error{missingHash: confirmation}
 	}
 
 	return nil
@@ -79,7 +79,7 @@ func (d *Postgres) FindUserByEmail(ctx context.Context, email string) (*User, er
 		&u.CreatedAt,
 		&u.UpdatedAt,
 	); err == pgx.ErrNoRows {
-		return nil, fmt.Errorf("user (email %q) not found in postgres", email)
+		return nil, Error{missingEmail: email}
 	} else if err != nil {
 		return nil, err
 	}

internal/data/user/user_sqlite.go

@@ -82,7 +82,7 @@ func (d *SQLite) ConfirmUser(ctx context.Context, confirmation string) error {
 	}
 
 	if conn.Changes() == 0 {
-		return errors.New("unknown confirmation_hash in sqlite")
+		return Error{missingHash: confirmation}
 	}
 
 	return nil
@@ -105,7 +105,7 @@ func (d *SQLite) FindUserByEmail(ctx context.Context, email string) (*User, erro
 	if found, err := stmt.Step(); err != nil {
 		return nil, err
 	} else if !found {
-		return nil, fmt.Errorf("user (email %q) not found in sqlite", email)
+		return nil, Error{missingEmail: email}
 	}
 
 	usr, err := sqliteUser(stmt)

internal/frontend/account/login.go

@@ -37,12 +37,12 @@ func (srv server) loginForm(w http.ResponseWriter, r *http.Request) {
 
 	usr, err := srv.userdb.FindUserByEmail(ctx, email)
 	if err != nil {
-		srv.http.Fail(ctx, w, err, "msg", "find user for auth")
+		srv.http.Fail(ctx, w, err, "login.tmpl", "msg", "find user for auth")
 		return
 	}
 
 	if err := usr.ValidatePassword(password); err != nil {
-		srv.http.Fail(ctx, w, err, "msg", "auth user")
+		srv.http.Fail(ctx, w, err, "login.tmpl", "msg", "auth user")
 		return
 	}
 

internal/frontend/account/register.go

@@ -70,7 +70,7 @@ func (srv server) registerConfirm(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if err := srv.userdb.ConfirmUser(ctx, confirmation); err != nil {
-		srv.http.Fail(ctx, w, err, "msg", "confirm user", "confirmation_hash", confirmation)
+		srv.http.Fail(ctx, w, err, "msg", "register-confirmed.tmpl", "confirm user", "confirmation_hash", confirmation)
 		return
 	}
 

pkg/frontend/frontend.go

@@ -182,6 +182,7 @@ func (srv *Server) Fail(ctx context.Context, w http.ResponseWriter, err error, k
 		return
 	}
 
+	tpl = "500.tmpl" // set back to Internal Server Error
 	srv.RenderTemplate(ctx, w, tpl, Data{}.
 		WithLog(err, keyvals...).
 		WithCode(http.StatusInternalServerError),

ui/includes/register-confirmed.tmpl

@@ -6,8 +6,12 @@
     <h3>Thank you for signing up</h3>
     <div class="msg">
       <p>
-      We confirmed your account. You can now use the site. 
+      {{- if .errors -}}
+          <div class="invalid-input">{{ .errors.confirmation_hash }}</div>
+      {{ else }}
       <a href="/login">Sign In</a>
+      We confirmed your account. You can now use the site.
+      {{ end }}
       </p>
     </div>
   </div>