Use _ValidationError only internally

Author: Ghesselink

__init__.py

@@ -1,11 +1,11 @@
 try:
     from parser.parse import parse
     from parser.file import file, open
-    from parser.errors import ValidationError, CollectedValidationErrors, DuplicateNameError, HeaderFieldError
+    from parser.errors import _ValidationError, CollectedValidationErrors, DuplicateNameError, HeaderFieldError
 except:
     from .parser.parse import parse 
     from .parser.file import file, open 
-    from .parser.errors import ValidationError, CollectedValidationErrors, DuplicateNameError, HeaderFieldError
+    from .parser.errors import _ValidationError, CollectedValidationErrors, DuplicateNameError, HeaderFieldError
 
-__all__ = ["parse", "open", "file", "ValidationError", 
+__all__ = ["parse", "open", "file", "_ValidationError", 
            "CollectedValidationErrors", "DuplicateNameError", "HeaderFieldError"] # for testing 

parser/errors.py

@@ -1,7 +1,10 @@
 from lark.exceptions import UnexpectedToken
 
-class ValidationError(Exception):
-    pass
+class _ValidationError(Exception):
+    def __init__(self, *args, **kwargs):
+        if self.__class__ is _ValidationError:
+            raise TypeError("Do not raise _ValidationError directly.")
+        super().__init__(*args, **kwargs)
 
 class ErrorCollector:
     def __init__(self):
@@ -14,7 +17,7 @@ def raise_if_any(self):
         if self.errors:
             raise CollectedValidationErrors(self.errors)
 
-class CollectedValidationErrors(ValidationError):
+class CollectedValidationErrors(_ValidationError):
     def __init__(self, errors):
         self.errors = errors
 
@@ -24,7 +27,7 @@ def asdict(self, with_message=True):
     def __str__(self):
         return f"{len(self.errors)} validation error(s) collected:\n" + "\n\n".join(str(e) for e in self.errors)
 
-class SyntaxError(ValidationError):
+class SyntaxError(_ValidationError):
     def __init__(self, filecontent, exception):
         self.filecontent = filecontent
         self.exception = exception
@@ -57,7 +60,7 @@ def __str__(self):
         return f"On line {d['lineno']} column {d['column']}:\nUnexpected {sth}{d['found_type']} ('{d['found_value']}')\nExpecting {exp}\n{d['lineno']:05d} | {d['line']}\n        {' ' * (self.exception.column - 1)}^"
 
 
-class DuplicateNameError(ValidationError):
+class DuplicateNameError(_ValidationError):
     def __init__(self, filecontent, name, linenumbers):
         self.name = name
         self.filecontent = filecontent
@@ -83,7 +86,7 @@ def build():
         return "\n".join(build())
 
 
-class HeaderFieldError(ValidationError):
+class HeaderFieldError(_ValidationError):
     def __init__(self, field, found_len, expected_len):
         self.field = field
         self.found_len = found_len

parser/parse.py

@@ -8,7 +8,7 @@
 # import transformer
 from .transformer import Transformer, entity_instance, make_header_ent, create_step_entity
 from .grammar import grammar, HEADER_FIELDS
-from .errors import HeaderFieldError, DuplicateNameError, ErrorCollector, ValidationError, SyntaxError
+from .errors import HeaderFieldError, DuplicateNameError, ErrorCollector, SyntaxError
 
 def validate_header_fields(header, error_collector, only_header = False):
     for field in HEADER_FIELDS.keys():

test_parser.py

@@ -1,13 +1,13 @@
 import glob
 import pytest
 
-from __init__ import parse, open, ValidationError, CollectedValidationErrors, DuplicateNameError, HeaderFieldError
+from __init__ import parse, open, _ValidationError, CollectedValidationErrors, DuplicateNameError, HeaderFieldError
 from contextlib import nullcontext
 
 
 def create_context(fn):
     if "fail_" in fn:
-        return pytest.raises(ValidationError)
+        return pytest.raises(_ValidationError)
     else:
         return nullcontext()
 
@@ -120,7 +120,7 @@ def test_file_mvd_attr():
 ])
 def test_invalid_headers_(filename):
     # error in header
-    with pytest.raises(ValidationError):
+    with pytest.raises(_ValidationError):
         parse(filename=filename, with_tree=False, only_header=True)
 
 @pytest.mark.parametrize("filename", [
@@ -134,11 +134,11 @@ def test_valid_headers(filename):
         parse(filename=filename, with_tree=False, only_header=True)
 
 def test_header_entity_fields():
-    with pytest.raises(ValidationError):
+    with pytest.raises(_ValidationError):
         parse(filename='fixtures/fail_too_many_header_entity_fields.ifc', only_header=True)
 
 def test_header_entity_fields_whole_file():
-    with pytest.raises(ValidationError):
+    with pytest.raises(_ValidationError):
         parse(filename='fixtures/fail_too_many_header_entity_fields.ifc')
 
 def test_header_entity_fields_whole_file():