bounds checking for Integer

Author: Jack Saunders

kim/field.py

@@ -30,6 +30,7 @@
     'none_not_allowed': 'This field cannot be null',
     'invalid_choice': 'invalid choice',
     'duplicates': 'duplicates found',
+    'out_of_bounds': 'value out of allowed range',
 }
 
 
@@ -296,6 +297,18 @@ class UserMapper(Mapper):
     serialize_pipeline = StringSerializePipeline
 
 
+class IntegerFieldOpts(FieldOpts):
+    """Custom FieldOpts class that provides additional config options for
+    :class:`.Integer`.
+
+    """
+
+    def __init__(self, **kwargs):
+        self.max = kwargs.pop('max', None)
+        self.min = kwargs.pop('min', None)
+        super(IntegerFieldOpts, self).__init__(**kwargs)
+
+
 class Integer(Field):
     """:class:`.Integer` represents a value that must be valid
     when passed to int()
@@ -312,6 +325,7 @@ class UserMapper(Mapper):
 
     """
 
+    opts_class = IntegerFieldOpts
     marshal_pipeline = IntegerMarshalPipeline
     serialize_pipeline = IntegerSerializePipeline
 

kim/pipelines/base.py

@@ -137,7 +137,7 @@ def run(self, **opts):
             return session.output
 
 
-@pipe()
+@pipe(run_if_none=True)
 def get_data_from_name(session):
     """extracts a specific key from data using field.name.  This pipe is
     typically used as the entry point to a chain of input pipes.

kim/pipelines/numeric.py

@@ -28,10 +28,29 @@ def is_valid_integer(session):
         raise session.field.invalid(error_type='type_error')
 
 
+@pipe()
+def bounds_check(session):
+    """pipe used to determine if a value can be coerced to an int
+
+    :param session: Kim pipeline session instance
+
+    """
+
+    max_ = session.field.opts.max
+    min_ = session.field.opts.min
+
+    if max_ is not None and session.data > max_:
+        raise session.field.invalid(error_type='out_of_bounds')
+    if min_ is not None and session.data < min_:
+        raise session.field.invalid(error_type='out_of_bounds')
+
+    return session.data
+
+
 class IntegerMarshalPipeline(MarshalPipeline):
 
     validation_pipes = \
-        [is_valid_integer, is_valid_choice] + MarshalPipeline.validation_pipes
+        [is_valid_integer, is_valid_choice, bounds_check] + MarshalPipeline.validation_pipes
 
 
 class IntegerSerializePipeline(SerializePipeline):

tests/test_pipelines/test_numeric.py

@@ -81,6 +81,17 @@ def test_marshal_read_only_integer():
     assert output == {}
 
 
+def test_marshal_default():
+
+    field = Integer(name='name', default=5)
+
+    output = {}
+    mapper_session = get_mapper_session(data={}, output=output)
+
+    field.marshal(mapper_session)
+    assert output == {'name': 5}
+
+
 def test_is_valid_choice():
 
     field = Integer(name='type', choices=[1, 2])
@@ -94,6 +105,24 @@ def test_is_valid_choice():
     assert output == {'type': 1}
 
 
+def test_min_max():
+
+    field = Integer(name='age', min=20, max=35)
+    output = {}
+
+    mapper_session = get_mapper_session(data={'age': 15}, output=output)
+    with pytest.raises(FieldInvalid):
+        field.marshal(mapper_session)
+
+    mapper_session = get_mapper_session(data={'age': 40}, output=output)
+    with pytest.raises(FieldInvalid):
+        field.marshal(mapper_session)
+
+    mapper_session = get_mapper_session(data={'age': 25}, output=output)
+    field.marshal(mapper_session)
+    assert output == {'age': 25}
+
+
 def test_is_valid_decimal_pipe():
     """test piping data through is_valid_decimal.
     """