Add the ArithmeticError exception

Author: zeroSteiner

docs/source/rule_engine/errors.rst

@@ -14,6 +14,11 @@ Data
 Exceptions
 ----------
 
+.. autoexception:: ArithmeticError
+   :members:
+   :show-inheritance:
+   :special-members: __init__
+
 .. autoexception:: AttributeResolutionError
    :members:
    :show-inheritance:
@@ -103,6 +108,7 @@ The class hierarchy for Rule Engine exceptions is:
 
    EngineError
     +-- EvaluationError
+         +-- ArithmeticError
          +-- AttributeResolutionError
          +-- AttributeTypeError
          +-- FunctionCallError

lib/rule_engine/ast.py

@@ -497,9 +497,9 @@ def __op_arithmetic(self, op, thing):
 		try:
 			result = op(left_value, right_value)
 		except ZeroDivisionError:
-			raise errors.EvaluationError('arithmetic error: division by zero') from None
+			raise errors.ArithmeticError('arithmetic error: division by zero') from None
 		except ArithmeticError:
-			raise errors.EvaluationError('arithmetic error') from None
+			raise errors.ArithmeticError('arithmetic error') from None
 		return result
 
 	_op_fdiv = functools.partialmethod(__op_arithmetic, operator.floordiv)

lib/rule_engine/errors.py

@@ -61,7 +61,6 @@ class EvaluationError(EngineError):
 	An error raised for issues which occur while the rule is being evaluated. This can occur at parse time while AST
 	nodes are being evaluated during the reduction phase.
 	"""
-	pass
 
 class SyntaxError(EngineError):
 	"""A base error for syntax related issues."""
@@ -171,7 +170,7 @@ def __init__(self, message, token=None):
 
 class AttributeResolutionError(EvaluationError):
 	"""
-	An error raised with an attribute can not be resolved to a value.
+	An error raised when an attribute can not be resolved to a value.
 
 	.. versionadded:: 2.0.0
 	"""
@@ -309,3 +308,10 @@ def __init__(self, message, error=None, function_name=None):
 		self.error = error
 		"""The exception from which this error was triggered."""
 		self.function_name = function_name
+
+class ArithmeticError(EvaluationError):
+	"""
+	An error raised when there is an issue performing an arithmetic operation.
+
+	.. versionadded:: 5.0.0
+	"""

tests/ast/expression/left_operator_right.py

@@ -96,6 +96,11 @@ def test_ast_expression_left_operator_right_arithmetic(self):
 		self.assertExpressionTests('mul', equals_value=8.0)
 		self.assertExpressionTests('pow', equals_value=16.0)
 
+	def test_ast_expression_left_operator_right_arithmetic_errors(self):
+		for operation in ('fdiv', 'tdiv'):
+			with self.assertRaises(errors.ArithmeticError):
+				self.assertExpressionTests(operation, ast.FloatExpression(context, 2.0), ast.FloatExpression(context, 0.0))
+
 	def test_ast_expression_left_operator_right_arithmetic_type_errors(self):
 		for operation in ('fdiv', 'tdiv', 'mod', 'mul', 'pow'):
 			with self.assertRaises(errors.EvaluationError):
@@ -106,7 +111,6 @@ def test_ast_expression_left_operator_right_arithmetic_type_errors(self):
 				self.assertExpressionTests(operation, ast.FloatExpression(context, 2.0), ast.BooleanExpression(context, True))
 			with self.assertRaises(errors.EvaluationError):
 				self.assertExpressionTests(operation, ast.BooleanExpression(context, True), ast.FloatExpression(context, 4.0))
-
 class AddExpressionTests(LeftOperatorRightExpresisonTestsBase):
 	ExpressionClass = ast.AddExpression
 	false_value = 0.0