feat(BA-4611): Add bridge methods between ScopeType/EntityType and RBACElementType (#9143)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: fregataa

changes/9143.feature.md

@@ -0,0 +1 @@
+Add bridge methods (`to_element()`, `to_scope_type()`, `to_entity_type()`) between `ScopeType`/`EntityType` and `RBACElementType` to enable incremental migration of upper layers independently of DB/ORM changes.

src/ai/backend/common/data/permission/types.py

@@ -270,6 +270,14 @@ def member_accessible_entity_types_in_domain(cls) -> set[EntityType]:
         """
         return {*cls._resource_types(), cls.USER}
 
+    def to_element(self) -> RBACElementType:
+        from ai.backend.common.exception import RBACTypeConversionError
+
+        try:
+            return RBACElementType(self.value)
+        except ValueError as e:
+            raise RBACTypeConversionError(f"{self!r} has no corresponding RBACElementType") from e
+
 
 class FieldType(enum.StrEnum):
     """Field types for RBAC field-scoped entities.
@@ -304,6 +312,14 @@ class ScopeType(enum.StrEnum):
     ARTIFACT_REVISION = "artifact_revision"
     ROLE = "role"
 
+    def to_element(self) -> RBACElementType:
+        from ai.backend.common.exception import RBACTypeConversionError
+
+        try:
+            return RBACElementType(self.value)
+        except ValueError as e:
+            raise RBACTypeConversionError(f"{self!r} has no corresponding RBACElementType") from e
+
 
 GLOBAL_SCOPE_ID = "global"
 
@@ -356,6 +372,30 @@ class RBACElementType(enum.StrEnum):
     # === Entity-level scopes (for entity-scope permissions) ===
     ARTIFACT_REVISION = "artifact_revision"
 
+    def to_scope_type(self) -> ScopeType:
+        """Temporary bridge for DB/ORM layers that still use ScopeType.
+
+        TODO: Remove after the RBAC ORM migration and ScopeType removal are complete.
+        """
+        from ai.backend.common.exception import RBACTypeConversionError
+
+        try:
+            return ScopeType(self.value)
+        except ValueError as e:
+            raise RBACTypeConversionError(f"{self!r} has no corresponding ScopeType") from e
+
+    def to_entity_type(self) -> EntityType:
+        """Temporary bridge for DB/ORM layers that still use EntityType.
+
+        TODO: Remove after the RBAC ORM migration and EntityType RBAC usage removal are complete.
+        """
+        from ai.backend.common.exception import RBACTypeConversionError
+
+        try:
+            return EntityType(self.value)
+        except ValueError as e:
+            raise RBACTypeConversionError(f"{self!r} has no corresponding EntityType") from e
+
 
 class RelationType(enum.StrEnum):
     """Classification of parent-child entity edges in BEP-1048.

src/ai/backend/common/exception.py

@@ -1153,3 +1153,17 @@ def error_code(self) -> ErrorCode:
             operation=ErrorOperation.AUTH,
             error_detail=ErrorDetail.INVALID_PARAMETERS,
         )
+
+
+class RBACTypeConversionError(BackendAIError, web.HTTPInternalServerError):
+    """Raised when an RBAC enum value cannot be converted to another RBAC enum type."""
+
+    error_type = "https://api.backend.ai/probs/rbac-type-conversion-error"
+    error_title = "RBAC type conversion failed."
+
+    def error_code(self) -> ErrorCode:
+        return ErrorCode(
+            domain=ErrorDomain.PERMISSION,
+            operation=ErrorOperation.GENERIC,
+            error_detail=ErrorDetail.INTERNAL_ERROR,
+        )