addressed review comments

clientapi/routing/admin.go

@@ -18,6 +18,7 @@ import (
 	"github.com/matrix-org/util"
 	"github.com/nats-io/nats.go"
 	"github.com/sirupsen/logrus"
+	"golang.org/x/exp/constraints"
 
 	clientapi "github.com/matrix-org/dendrite/clientapi/api"
 	"github.com/matrix-org/dendrite/internal/httputil"
@@ -39,8 +40,8 @@ func AdminCreateNewRegistrationToken(req *http.Request, cfg *config.ClientAPI, u
 	}
 	request := struct {
 		Token       string `json:"token"`
-		UsesAllowed int32  `json:"uses_allowed"`
+		UsesAllowed *int32 `json:"uses_allowed,omitempty"`
-		ExpiryTime  int64  `json:"expiry_time"`
+		ExpiryTime  *int64 `json:"expiry_time,omitempty"`
 		Length      int32  `json:"length"`
 	}{}
 
@@ -87,15 +88,13 @@ func AdminCreateNewRegistrationToken(req *http.Request, cfg *config.ClientAPI, u
 		}
 	}
 	// At this point, we have a valid token, either through request body or through random generation.
-
+	if usesAllowed != nil && *usesAllowed < 0 {
-	if usesAllowed < 0 {
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: spec.BadJSON("uses_allowed must be a non-negative integer or null"),
 		}
 	}
-
+	if expiryTime != nil && spec.Timestamp(*expiryTime).Time().Before(time.Now()) {
-	if expiryTime != 0 && expiryTime < time.Now().UnixNano()/int64(time.Millisecond) {
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: spec.BadJSON("expiry_time must not be in the past"),
@@ -106,10 +105,10 @@ func AdminCreateNewRegistrationToken(req *http.Request, cfg *config.ClientAPI, u
 	// If usesAllowed or expiryTime is 0, it means they are not present in the request. NULL (indicating unlimited uses / no expiration will be persisted in DB)
 	registrationToken := &clientapi.RegistrationToken{
 		Token:       &token,
-		UsesAllowed: &usesAllowed,
+		UsesAllowed: usesAllowed,
 		Pending:     &pending,
 		Completed:   &completed,
-		ExpiryTime:  &expiryTime,
+		ExpiryTime:  expiryTime,
 	}
 	created, err := userAPI.PerformAdminCreateRegistrationToken(req.Context(), registrationToken)
 	if !created {
@@ -130,19 +129,19 @@ func AdminCreateNewRegistrationToken(req *http.Request, cfg *config.ClientAPI, u
 		Code: 200,
 		JSON: map[string]interface{}{
 			"token":        token,
-			"uses_allowed": getReturnValueForUsesAllowed(usesAllowed),
+			"uses_allowed": getReturnValue(usesAllowed),
 			"pending":      pending,
 			"completed":    completed,
-			"expiry_time":  getReturnValueExpiryTime(expiryTime),
+			"expiry_time":  getReturnValue(expiryTime),
 		},
 	}
 }
 
-func getReturnValueForUsesAllowed(usesAllowed int32) interface{} {
+func getReturnValue[t constraints.Integer](in *t) any {
-	if usesAllowed == 0 {
+	if in == nil {
 		return nil
 	}
-	return usesAllowed
+	return *in
 }
 
 func AdminListRegistrationTokens(req *http.Request, cfg *config.ClientAPI, userAPI userapi.ClientUserAPI) util.JSONResponse {
@@ -176,13 +175,6 @@ func AdminListRegistrationTokens(req *http.Request, cfg *config.ClientAPI, userA
 	}
 }
 
-func getReturnValueExpiryTime(expiryTime int64) interface{} {
-	if expiryTime == 0 {
-		return nil
-	}
-	return expiryTime
-}
-
 func AdminGetRegistrationToken(req *http.Request, cfg *config.ClientAPI, userAPI userapi.ClientUserAPI) util.JSONResponse {
 	vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
 	if err != nil {

userapi/storage/postgres/registration_tokens_table.go

@@ -106,8 +106,8 @@ func (s *registrationTokenStatements) InsertRegistrationToken(ctx context.Contex
 	_, err := stmt.ExecContext(
 		ctx,
 		*registrationToken.Token,
-		nullIfZero(*registrationToken.UsesAllowed),
+		getInsertValue(registrationToken.UsesAllowed),
-		nullIfZero(*registrationToken.ExpiryTime),
+		getInsertValue(registrationToken.ExpiryTime),
 		*registrationToken.Pending,
 		*registrationToken.Completed)
 	if err != nil {
@@ -116,11 +116,11 @@ func (s *registrationTokenStatements) InsertRegistrationToken(ctx context.Contex
 	return true, nil
 }
 
-func nullIfZero[t constraints.Integer](in t) any {
+func getInsertValue[t constraints.Integer](in *t) any {
-	if in == 0 {
+	if in == nil {
 		return nil
 	}
-	return in
+	return *in
 }
 
 func (s *registrationTokenStatements) ListRegistrationTokens(ctx context.Context, tx *sql.Tx, returnAll bool, valid bool) ([]api.RegistrationToken, error) {

userapi/storage/sqlite3/registration_tokens_table.go

@@ -106,8 +106,8 @@ func (s *registrationTokenStatements) InsertRegistrationToken(ctx context.Contex
 	_, err := stmt.ExecContext(
 		ctx,
 		*registrationToken.Token,
-		nullIfZero(*registrationToken.UsesAllowed),
+		getInsertValue(registrationToken.UsesAllowed),
-		nullIfZero(*registrationToken.ExpiryTime),
+		getInsertValue(registrationToken.ExpiryTime),
 		*registrationToken.Pending,
 		*registrationToken.Completed)
 	if err != nil {
@@ -116,11 +116,11 @@ func (s *registrationTokenStatements) InsertRegistrationToken(ctx context.Contex
 	return true, nil
 }
 
-func nullIfZero[t constraints.Integer](in t) any {
+func getInsertValue[t constraints.Integer](in *t) any {
-	if in == 0 {
+	if in == nil {
 		return nil
 	}
-	return in
+	return *in
 }
 
 func (s *registrationTokenStatements) ListRegistrationTokens(ctx context.Context, tx *sql.Tx, returnAll bool, valid bool) ([]api.RegistrationToken, error) {