add BaseAttrib.audit() method

Destroys ATTRIB and ATTDEF entities without
a "tag" attribute.

src/ezdxf/audit.py

@@ -93,6 +93,7 @@ class AuditError(IntEnum):
     INVALID_CREASE_VALUE_COUNT = 224
     INVALID_ELLIPSE_RATIO = 225
     INVALID_HATCH_BOUNDARY_PATH = 226
+    TAG_ATTRIBUTE_MISSING = 227
 
 
 REQUIRED_ROOT_DICT_ENTRIES = ("ACAD_GROUP", "ACAD_PLOTSTYLENAME")
@@ -111,7 +112,7 @@ def __init__(
         self.message: str = message  # error message
         self.data: Any = data  # additional data as an arbitrary object
 
-# pylint: disable=too-many-public-methods
+
 class Auditor:
     def __init__(self, doc: Drawing) -> None:
         assert doc is not None and doc.rootdict is not None and doc.entitydb is not None

src/ezdxf/entities/attrib.py

@@ -4,6 +4,8 @@
 from typing import TYPE_CHECKING, Optional
 from typing_extensions import Self
 import copy
+
+from ezdxf.audit import Auditor, AuditError
 from ezdxf.lldxf import validator
 from ezdxf.math import NULLVEC, Vec3, Z_AXIS, OCS, Matrix44
 from ezdxf.lldxf.attributes import (
@@ -40,7 +42,6 @@
 if TYPE_CHECKING:
     from ezdxf.lldxf.tagwriter import AbstractTagWriter
     from ezdxf.lldxf.tags import Tags
-    from ezdxf.entities import DXFEntity
     from ezdxf import xref
 
 
@@ -81,6 +82,7 @@
     # ezdxf stores the last group code 280 as "lock_position" attribute and does
     # not export a version tag for any DXF version.
     # Tag string (cannot contain spaces):
+    # Mandatory by AutoCAD!
     "tag": DXFAttr(
         2,
         default="",
@@ -402,6 +404,16 @@ def transform(self, m: Matrix44) -> Self:
             self.post_transform(m)
         return self
 
+    def audit(self, auditor: Auditor) -> None:
+        """Validity check."""
+        super().audit(auditor)
+        if not self.dxf.hasattr("tag"):
+            auditor.fixed_error(
+                code=AuditError.TAG_ATTRIBUTE_MISSING,
+                message=f'Missing mandatory "tag" attribute, entity {str(self)} deleted.',
+            )
+            auditor.trash(self)
+
 
 def _update_content_from_mtext(text: Text, mtext: MText) -> None:
     content = mtext.plain_text(split=True, fast=True)

tests/test_02_dxf_graphics/test_208_attrib.py

@@ -9,6 +9,7 @@
 from ezdxf.lldxf.const import DXF12, DXF2000
 from ezdxf.lldxf.tagwriter import TagCollector, basic_tags_from_text
 from ezdxf.math import Matrix44
+from ezdxf.audit import Auditor
 
 TEST_CLASS = Attrib
 TEST_TYPE = "ATTRIB"
@@ -295,6 +296,19 @@ def test_version_without_lock_position():
     assert attrib.dxf.lock_position == 7
 
 
+def test_audit_destroys_attrib_without_tag_attribute(doc):
+    # Unbound entities cannot be audited!
+    attrib = Attrib.new()
+    doc.modelspace().add_entity(attrib)
+
+    auditor = Auditor(doc)
+    attrib.audit(auditor)
+    auditor.empty_trashcan()
+
+    assert len(auditor.fixes) == 1
+    assert attrib.is_alive is False
+
+
 LOCK_POSITION_AND_VERSION = """0
 ATTRIB
 5

tests/test_04_dxf_high_level_structs/test_424_audit.py

@@ -211,7 +211,8 @@ def test_remove_standalone_attrib_entities_from_blocks():
     # The model space is just a BLOCK!
     doc = ezdxf.new()
     msp = doc.modelspace()
-    msp.add_entity(Attrib())
+    # Missing tag is a different issue!
+    msp.add_entity(Attrib.new(dxfattribs={"tag": "test"}))
     auditor = doc.audit()
     assert len(list(msp)) == 0
     assert len(auditor.fixes) == 1